GEOARCHAEOLOGICAL INVESTIGATIONS OF SITE FORMATION

GEOARCHAEOLOGICAL INVESTIGATIONS OF SITE FORMATION PROCESSES

IN AREA 15 AT THE GAULT SITE, BELL COUNTY, TEXAS

Presented to the Graduate Council of

Texas State University-San Marcos

in Partial Fulfillment

of the Requirements

for the Degree

Master of ARTS

by

Anastasia Gilmer, B.S.

San Marcos, Texas

August 2013

GEOARCHAEOLOGICAL INVESTIGATIONS OF SITE FORMATION PROCESSES

IN AREA 15 AT THE GAULT SITE, BELL COUNTY, TEXAS

Approved:

J. Michael Willoughby

Dean of the Graduate College

Committee Members Approved:

C. Britt Bousman, Chair

Michael B. Collins

Charles Frederick

COPYRIGHT

by

Anastasia Gilmer

2013

FAIR USE AND AUTHOR’S PERMISSION STATEMENT

Fair Use

This work is protected by the Copyright Laws of the United States (Public Law 94-553,

section 107). Consistent with fair use as defined in the Copyright Laws, brief quotations

from this material are allowed with proper acknowledgment. Use of this material for

financial gain without the author’s express written permission is not allowed.

Duplication Permission

As the copyright holder of this work I, Anastasia Gilmer, authorize duplication of this

work, in whole or in part, for educational or scholarly purposes only.

DEDICATION

To my parents. Thank you for your love, support, and encouragement.

vi

ACKNOWLEDGEMENTS

Particular thanks to my committee members for their insights, encouragement,

and time: Dr. Bousman for his support and always making time for me when I needed to

talk, Dr. Collins for his guidance and wisdom, and Dr. Frederick for his advice and

unending patience while I was at his lab.

My sincerest appreciation goes to the Gault School of Archaeological Research

for providing me with the opportunity to conduct this research. Clark Wernecke, Nancy

Littlefield, and Steve Howard were always willing to answer my questions and be out at

the site when I needed to be there.

I would like to thank the Center for Archaeological Studies at Texas State and

especially David Yelacic for helping me with the magnetic susceptibility equipment.

Analyses were conducted at Charles Fredericks’ laboratory. The generous

support provided by himself and Brittney Gregory is appreciated.

The preliminary research results of Sergio Ayala, Jennifer Gandy, and Nick

Rodriguez, were discussed here and provided invaluable archaeological data to

supplement this geoarchaeological study. Also, a spreadsheet created by Paul Lehman

was used to calculate texture as well as the mean and standard deviation for each sample.

Finally, I would like to thank Robert Lassen for his comments on an earlier draft.

This manuscript was submitted on April 29, 2013.

vii

TABLE OF CONTENTS

Page

ACKNOWLEDGEMENTS ............................................................................................... vi

LIST OF TABLES ...............................................................................................................x

LIST OF FIGURES ........................................................................................................... xi

CHAPTER

1. INTRODUCTION .............................................................................................1

Objectives and Justification of Research .....................................................1

Archaeological Investigations at the Gault Site ..........................................3

Geoarchaeological Investigations at the Gault Site ....................................6

The Cultural Components at the Gault Site .................................................6

OSL Dating the Gault site ................................................................8

Brief Outline.................................................................................................9

2. REDEFINING CLOVIS ..................................................................................11

Subsistence and Mobility ...........................................................................13

Traditional View as Hunting Specialists .......................................13

Growing View as Generalized Hunters and Gatherers .................14

Fauna at Gault ...............................................................................16

Clovis Lithic Technology ...........................................................................16

Clovis Lithics .................................................................................16

Lithic Insights from Gault ..............................................................17

The Clovis-First Paradigm ........................................................................19

Pre-Clovis Occupations .................................................................19

Why the Slow Rate of Acceptance? ................................................21

3. ENVIRONMENTAL SETTING ....................................................................24

Site Location ..............................................................................................24

Modern Environment .................................................................................30

Climate ...........................................................................................30

viii

Hydrology ......................................................................................32

Flora ..............................................................................................33

Fauna .............................................................................................34

Relationship between site setting and cultural history at Gault ....36

Bedrock Geology of the Balcones Escarpment and Edwards Plateau ......37

The Cretaceous System ..................................................................37

Geology of the Balcones Escarpment ............................................38

Geology of the Edward’s Plateau ..................................................38

Soils of the Edwards Plateau .....................................................................39

Soils at the Gault and Friedkin Sites .............................................40

Late Quaternary Environmental History and Landscape Evolution in

Central Texas .......................................................................................40

Stable Isotopic Analyses ................................................................43

Pollen Analyses ..............................................................................46

Faunal Analyses .............................................................................48

Geomorphic Analyses ....................................................................50

Archaeological Site Preservation and Formation Processes on the

Edward’s Plateau.................................................................................52

Cultural Remains versus the Original Cultural Component .........53

Geomorphic Processes...................................................................53

Pedoturbation ................................................................................54

Landscape Evolution and Formation Processes within Buttermilk Creek

Valley ...................................................................................................57

Landscape Evolution and Alluvial History ....................................57

Site Formation Processes ..............................................................59

Summary ....................................................................................................64

4. METHODS ......................................................................................................65

Field Descriptions and Profile Drawings ..................................................65

Sample Collection ......................................................................................66

Particle-Size Analysis ................................................................................66

Organic Carbon and Organic Matter Content ..........................................72

Calcium Carbonate Content ......................................................................75

Magnetic Susceptibility ..............................................................................78

5. RESULTS ........................................................................................................80

General comments .....................................................................................80

Column A ...................................................................................................83

Texture Analysis .............................................................................83

Calcium Carbonate ........................................................................86

Organic Carbon and Organic Matter ............................................86

Magnetic Susceptibility ..................................................................87

Field Observations .........................................................................87

Artifacts ..........................................................................................87

Column B ...................................................................................................88

ix





Artifacts ..........................................................................................90

Column C ...................................................................................................90






Column D ...................................................................................................93






Artifacts ..........................................................................................95

6. DISCUSSION ..................................................................................................96

Area 15 .......................................................................................................96

Sedimentary Processes...................................................................96

Pedogenic Processes ....................................................................103

Post-Depositional Processes .......................................................108

Buttermilk Creek Valley ...........................................................................111

Sedimentary and Pedogenic Processes ........................................111

Post-Depositional Processes .......................................................113

Central Texas ...........................................................................................115

Where to Look for “Old Dirt” .................................................................116

Possible Directions of Future Research ..................................................118

Photo-Sieving ...............................................................................118

Size-Sorting ..................................................................................118

OSL dating ...................................................................................118

7. CONCLUSIONS............................................................................................120

APPENDIX A: GEOLOGIC PROFILES AND DESCRIPTIONS .................................123

APPENDIX B: RESULTING DATA FROM ANALYSES ...........................................137

REFERENCES CITED ....................................................................................................155

x

LIST OF TABLES

Table Page

1. Legend for map unit symbols in Figure 13 ..................................................................42

2. Simplified characterization of site types and settings in Central Texas ......................54

3. Multiple-aliquot OSL ages on quartz grains ................................................................81

4. Summary of the changes in the hydrologic regime at Area 15 ..................................101

5. The relationships between the cultural horizons, soil horizons, and stratigraphic units

in Columns A, B, and C .............................................................................................105

6. Comparison between the stratigraphic units at Fort Hood, Buttermilk Creek, and Area

15................................................................................................................................112

7. Comparison between the stratigraphy in Area 8 and Area 15 ...................................113

xi

LIST OF FIGURES

Figure Page

1. Location of the Gault site, 41BL323..............................................................................2

2. Excavation areas at the Gault site. .................................................................................5

3. The natural regions of Texas ........................................................................................25

4. Buttermilk Creek Valley ..............................................................................................26

5. Looking downstream along Buttermilk Creek .............................................................27

6. Photo of the current excavation block taken from Buttermilk Creek ..........................27

7. River systems near Gault .............................................................................................28

8. Bedrock geology surrounding the Gault site. ..............................................................29

9. Sedimentary deposits at the Gault site .........................................................................29

10. The climatic regions of Texas ......................................................................................31

11. Blair’s biotic provinces of Texas .................................................................................35

12. Faunal Regions of Texas ..............................................................................................35

13. Soil map of area around the Gault site .........................................................................41

14. Locations where bulk sediment samples were collected in Columns A, B, C and D ..67

15. Column A along the west wall of the Area 15 excavation block, facing west. ...........68

16. Column B along the north wall of the Area 15 excavation block ................................69

17. Column C along the north wall of the Area 15 excavation block ................................69

18. Column D was collected from the pedestaled cobbles along the east wall .................70

xii

19. Ro-Tap Model E Test Sieve Shaker .............................................................................73

20. The crucibles used in the loss-on-ignition method ......................................................77

21. The furnace, heated to 950oC, used in the loss-on-ignition method ............................77

22. Chittick Apparatus .......................................................................................................77

23. Analysis results for Column A .....................................................................................84

24. Analysis results for Column A .....................................................................................85

25. Number and weight (grams) of flakes under 93.00 m in Area 15 ...............................88

26. Analysis results for Column B .....................................................................................89

27. Analysis results for Column C .....................................................................................91

28. Analysis results for Column D .....................................................................................94

29. The pollen data from Boriack Bog and the NGRIP and GRIP ice core record as

compared to stratigraphic units at Area 15 ..................................................................98

30. Approximate boundaries of the stratigraphic units across the excavations block .....106

31. Profile that includes all stratigraphic units and pedogenic horizons and highlights data

from Column A and B................................................................................................107

1

1. INTRODUCTION

The Gault site is a stratified, multi-component prehistoric site located northwest

of Georgetown, Texas (Figure 1). The site was repeatedly, and at times intensely,

occupied in all major periods of the prehistoric era in Central Texas. This thesis presents

a geoarchaeological analysis to reconstruct the natural formation processes that have

affected the sediment revealed in the current excavation block at the Gault site.

Objectives and Justification of Research

The archaeological record has cultural as well as natural components (Butzer

1982; Schiffer 1983). Butzer (1982) espouses a multi-disciplinary approach, referred to

as contextual archaeology, for interpreting archaeological deposits. In his model, the

factors within the ecosystem can be divided into cultural and non-cultural categories.

These categories are further sub-divided into four components: cultural (artifacts and

features), biological (flora and fauna), non-biological (physical landscape), and climate.

Understanding the non-cultural aspects of a site expands our understanding of the

environment in which people lived.

In addition to gaining a better understanding of past cultures, the natural

component of an archaeological site can be used to determine the context of cultural

material. As stated by Schiffer (1983:697), artifacts may be viewed “as merely peculiar

particles in a sedimentary matrix that potentially have been subjected by cultural and

2

2

Figure 1. Location of the Gault site, 41BL323.

natural formation processes to a variety of mechanical and chemical alterations.” Natural

formation processes, or non-cultural formation processes, are environmental factors that

form and affect the archaeological record (Schiffer 1987:7). The causes and

consequences of formation processes occur in a regular and predictable manner that can

be anticipated by experimental laws and empirical generalizations. The reconstruction of

natural formation processes is tied into the analytical methods of other disciplines, such

as geology and soil science (Schiffer 1987:21-22).

The main objective of this thesis is to determine the depositional and post-

depositional integrity of the sediment and cultural material from the current excavation

block at the Gault site, referred to as Area 15. Particular emphasis is placed upon the

sediment that is Paleoindian-aged and older due to the importance of determining the

3

integrity of pre-Clovis and Clovis materials. Investigations suggest evidence of a pre-

Clovis occupation at the Gault site (Collins and Bradley 2008).

Standard sediment and soil analyses were used to analytically examine

sedimentary processes, pedogenic qualities of the soil, and effects of post-depositional

processes on the sediment in order to trace the natural formation processes. Determining

the depositional and post-depositional integrity of the pre-Archaic sediment and cultural

material will increase the understanding of the Paleoindian record at the Gault site, as

well as provide further evidence regarding pre-Clovis occupation. The results of this

study, which will aid in future interpretations and research at the Gault site, could support

the preserved context of the Paleoindian strata, suggest disturbance of the sediment, or be

inconclusive.

Archaeological Investigations at the Gault Site

There is a long history of archaeological investigations at the Gault site. It was

first excavated in 1929 and 1930 by J. E. Pearce from the University of Texas. The

property underwent extensive looting from approximately 1908 to 1998. A pay-to-dig

business operated on the site for a number of years (Collins 1999a, 2002; Collins et al.

1991). Visits to the property in 1988 and brief excavations in 1991 by the Texas

Archaeological Research Laboratory (TARL) at the University of Texas established the

presence of undisturbed Paleoindian strata beneath the looted Archaic strata (Collins et

al. 1991). Neither the University of Texas nor the Texas Historical Commission could

come to an agreement with the landowners for professional excavations on the site,

however (Black 2001; Collins 1999a; GSAR 2011a).

4

After ownership of the property changed in 1998, the new landowners agreed in

1999 to a three year lease of the property between 1999 and 2002 by the University of

Texas System. Large-scale excavations were conducted by personnel and students under

auspices of TARL and under the direction of Drs. Michael B. Collins and Thomas R.

Hester. Collins has remained the principle investigator since Hester left the project in

2000. Additional assistance was provided by individuals from multiple universities and

organizations (Collins 2002; GSAR 2011a).

Researchers from Texas A&M University, in cooperation with Collins and Hester,

excavated at a part of the site termed Excavation Area 8, informally referred to as “The

Lindsey Pit” (Figure 2). Two field schools were conducted in Area 8. The first was run

in the spring of 2000 under the direction of Drs. Harry Shafer and Michael Waters. The

subsequent field school was conducted by Dr. David Carlson for the Texas

Archaeological Society in the summer of 2001 (Waters et al. 2011a). A number of theses

and dissertations from Texas A&M students focused on Area 8 (Alexander 2008;

Dickens 2005; Luchsinger 2002; Minchak 2007; Pevny 2009; Smallwood 2006;

Wiederhold 2004). Michael R. Waters, Charlotte D. Pevny, and David L. Carlson (2011)

published a monograph detailing Texas A&M University’s investigations at Area 8, with

particular focus on the Clovis component.

After the Gault School of Archaeological Research (GSAR) was founded in 2006,

the property containing the Gault site was purchased in 2007 and work on the site

resumed (GSAR 2011a). The property was donated to the Archaeological Conservancy

(TAC) in late 2007. Area 15 (Figure 2) was opened in the fall of 2007 to expose a large

section of deeply buried sediment. The intended goal is to investigate archaeological

5

Figure 2. Excavation areas at the Gault site.

evidence that resides in the deposits that are pre-Clovis in age (GSAR 2011b). The Gault

Project moved to Texas State University in August of 2010 (GSAR 2011a). Excavations

at Area 15 were continuous during the work on this thesis. Investigations at the site

remain active today.

6

Geoarchaeological Investigations at the Gault Site

Existing geoarchaeological investigations at the Gault site include: a geological

site model for Buttermilk Creek (Gibson 1997); a micromorphological analysis of

sediments from Area 8 (Luchsinger 2002); an investigation of natural formation

processes affecting the Clovis component of Area 8 (Alexander 2008); and a seismic

reflection imaging study to generate sediment profiles (Hildebrand et al. 2007).

After working at Area 8 at the Gault site, Michael Waters conducted excavations

focused on recovering the pre-Clovis material at the neighboring Debra L. Friedkin site

(Waters et al. 2011b). The Friedkin site is approximately 250 meters downstream from

the Gault site (Waters et al. 2011b). An examination of natural site formation processes

affecting the cultural components within one of the excavation blocks at the Friedkin site

was conducted (Keene 2009) and was subsequently expanded by Driese et al. (2013).

The results and implications of these geoarchaeological investigations are discussed in

further detail in Chapters 3 and 6.

The Cultural Components at the Gault site

The record from the Late Prehistoric Period (1200-250 calendar years B.P.) is

relatively sparse and is limited to a few pottery sherds and arrow points. The Archaic

midden, originally 12 or 15 hectares in extent and up to 2.5 meters in thickness, has been

heavily disturbed by looting throughout much of the site. Diagnostic points, missed by

looters, indicate occupations spanned the Archaic (8900-1200 calendar years B.P.)

(Collins 2002). In Area 15, however, portions of the midden remained intact and un-

looted (GSAR 2011b). Artifact and faunal materials suggest a wide range of activities;

7

such as hunting, woodworking, and plant-food processing. Archaic hunters and gatherers

likely found the area to be ideal for their diverse food base, with its easy access to chert,

springs, and a wide variety of flora and fauna (Collins 2002).

Paleoindian aged (>12,000-8900 calendar years B.P.) deposits are found across

the majority of the site. Late and Early Paleoindian cultural materials are present. The

Late Paleoindian component has yielded a number of previously unrecognized forms of

lithic materials in addition to the diagnostic materials typical to this period. In Area 15,

Late Paleoindian occupations are sparse. The diagnostic artifacts include Angostura,

Wilson, Dalton and St. Mary’s Hall.

While the Folsom and Clovis components from the Early Paleoindian period are

well established across the site, the lightweight tool kit of the nomadic Folsom bison

hunters is not as well represented as other technologies. The majority of diagnostic

Folsom materials are primarily lithic scatter from the re-tooling process. One diagnostic

Folsom artifact has been recovered from in Area 15. The point, however, was found in

the fill from an earth oven.

The Gault site has a rich Clovis record. The artifacts and faunal materials from

Gault suggest that people living during the Clovis era were engaged in a much more

diverse life-way than previously believed by the archaeological community (Collins

2002). For a more detailed discussion of the Clovis record at the Gault site and its

implications for understanding the Clovis culture, see Chapter 2.

In 2001, a rectangular stone pavement, closely oriented along cardinal directions,

was discovered at Area 12 (Figure 2), which is also referred to as Bobcat 18. This

surface is interpreted as a habitation floor. The pavement, confined to a thickness of 10

8

cm, is in a matrix of calcium carbonate-rich granular clay with few stones (Wernecke

2002). The stone pavement was surrounded by a toss zone of bison bone to the south and

southwest as well as burned chert artifacts to the north and northeast. Blade-segment

tools were found on top of the gravel pavement. Use-wear studies revealed sickle-sheen

on the blade tools (Shoberg 2010). Optically Stimulated Luminescence (OSL) of silt-

sized aeolian quartz grains was used to date the burial of the stone pavement to

14,980±450 calendar years B.P. (Rink and Collins 2013).

Area 15, the focus of this thesis, has yielded further evidence of a pre-Clovis

occupation at the Gault site. A well-defined Clovis component is contained within a dark

clay with soft carbonate nodules. Limonitic clay loam with hard carbonate nodules

stratigraphically underlies the clay. Artifacts technologically distinguishable from the

Clovis assemblage are found in the limonitic clay loam (Collins and Bradley 2008). The

artifacts are tentatively divided into upper and lower components based on technological

and stratigraphic changes through the profile (Michael Collins, personal communication).

The aeolian-derived silt-sized quartz grains from the upper pre-Clovis component have

been dated with OSL to 13,300-13,800 calendar years BP. The lower pre-Clovis

component lies beneath the OSL date of 13,800 calendar years BP (Rink and Collins

2013). Additional OSL samples were collected to create a more refined chronology but

had not been processed at the time this thesis was completed. Regardless, these dates

suggest artifacts were deposited prior to the Clovis interval of 12,900-13,500 calendar

years ago.

OSL Dating the Gault Site. OSL dating was possible because fairly high

quantities of silt-sized aeolian quartz grains have been detected in the sediment at Gault

9

(Luchsinger 2002). Defects in certain materials, such as quartz and plagioclase, create

traps for excited electrons. A stimulus, such as light or heat, will reset these traps, and

once emptied, the traps begin to refill. The amount of time since the last exposure to

light, or the zeroing event, can be determined through OSL dating by measuring the light

emitted from the material after it is exposed to an external light source. Many

depositional processes do not provide enough exposure to sunlight for each grain

involved in the depositional event to be zeroed. Aeolian derived sediments, such as those

found at Gault, are ideal for OSL dating. The significant amount of time spent airborne

means the traps within these grains were likely reset (Feathers 2003).

If the traps within the aeolian derived quartz grains from the stone pavement in

Area 12 were reset prior to deposition, the burial date for the pavement is 14,980±450

calendar years B.P. The very low overdispersion in the equivalent dose distribution

(between 0-12%) for the OSL samples collected from Areas 12 and 15 indicate the grains

were well exposed to light at the time of deposition and provide great confidence in the

accuracy of the results (Rink and Collins 2013).

Brief Outline

Chapter 2 reexamines the Clovis interval in regards to the Clovis-first paradigm,

lithic technology, and subsistence and mobility. This chapter synthesizes arguments that

redefine the Clovis culture in the face of growing evidence for a pre-Clovis occupation of

the Americas. Chapter 3 places the Gault site in its environmental context through a

discussion of Late Pleistocene and Holocene geology, geomorphology, hydrology, soils,

flora, fauna, and climate changes. Chapter 4 introduces the methodology used in this

10

thesis to analyze the sedimentary, pedogenic, and post-depositional processes that have

affected the geological context of the artifacts. Chapter 5, 6, and 7 respectively provide

the results of the analyses, a discussion of the results, and conclusions.

11

2. REDEFINING CLOVIS

For the last 80 years, the Clovis prehistoric technological complex, defined by the

use of a unique stone, bone, and ivory tool kit, has been considered the first culture to

emerge in North America (Collins 2002; Haynes 2002). Clovis artifacts were produced

through a remarkably uniform process across sub-glacial North America and into

northern South America between 13,500-12,900 calendar years ago (Bradley et al.

2010:1). The archaeological community has generally viewed Clovis as a highly mobile,

specialized hunter-gatherer lifeway that spread across North America in less than one

thousand years after humans first migrated from Beringia through the ice-free corridor

between the Laurentide and Cordilleran Ice Sheets (Haynes 1964; Kelly and Todd 1988).

This conventional wisdom, however, does not agree with archaeological material lately

brought to light (Collins 2002, 2007; Dillehay 1997). In recent decades, archaeologists,

now armed with fresh research goals and methods, have discovered new Pleistocene-aged

sites and revisited others. Evidence of archaeological horizons stratigraphically

underlying Clovis components are now well-documented at a number of sites (Collins

2010; Goebel et al. 2008), including the Gault site (Collins and Bradley 2008).

Understanding the Clovis record, according to Waters and Stafford (2007), has important

implications for inferring the origins of Clovis, assessing the Clovis-first model for the

peopling of the Americas, and evaluating the possibility of a pre-Clovis occupation of the

Americas.

12

An unusually rich archaeological record is present at the Gault site, especially in

the Clovis strata (Collins 2002). Additionally, as discussed in the introduction,

investigations suggest a technologically distinct pre-Clovis component underlying the

Clovis component in Area 15 (Collins and Bradley 2008; Rink and Collins 2013) and

Area 12 (Rink and Collins 2013).

The Gault site, like Aubrey (Ferring 2001), was a camp site, rather than the more

frequently excavated kill site. Gault was intensely and repeatedly occupied by humans in

all the major periods of the prehistoric era. The Clovis record at the Gault site, consisting

of prolific and diverse lithic artifacts and a small amount of mega-faunal materials,

suggests an alternative assessment of the Clovis culture and the traditional Clovis-first

view. The Clovis people may have been generalized hunters and gatherers, who used

resources other than big-game, and were less mobile than generally believed (Collins

2002, 2007, 2010; Ferring 2001). The extensive archaeological record, with clearly

defined Clovis and pre-Clovis assemblages, makes the Gault site particularly well suited

for re-assessing the pre-Clovis and Clovis record.

While it is clear that new models are needed to explain the peopling of the

Americas (Waters and Stafford 2007), this chapter will not revisit the arguments for

which migration routes or origin point best fit the archaeological and genetic data or the

origins of Clovis technology. Instead, the focus is on the growing body of data collected

in recent years that diverges from the traditional view of the Clovis culture. This chapter

argues that Clovis should be redefined with respect to subsistence and mobility, lithic

technology, and the Clovis-First paradigm.

13

Subsistence and Mobility

Traditional View as Hunting Specialists. Traditionally, the Clovis people were

considered hunting specialists (Walker and Driskell 2007:xi). The large number of

mammoth bones and occasional bison remains associated with Clovis sites gave birth to

the view of Clovis peoples as highly effective big-game hunters. Until recent years, few

archaeologists looked for Pleistocene-aged geologic surfaces to find the “boneless” sites,

as opposed to the more arresting megafauna remains (Meltzer 2009:91-92). The bias

toward discovering kill sites rather than “boneless” Paleoindian sites has resulted in kill

sites representing the majority of the known Clovis record. The idea of Clovis people as

hunting specialists became so imbedded in the archaeological consciousness that the

model was applied across North America, even though kill sites were predominately

confined to certain regions (Meltzer 2009:92).

It has been suggested by Haynes (2009) that the populations of some of the

frequently found megafuana, including mammoth, mastodont, horse, and camel, were not

as abundant everywhere as it is generally assumed. Relatively high numbers of fluted-

points and megafaunal fossils have been found in clusters across North America,

suggesting that certain parts of the continent were better for megafauna and Clovis

megafuana-hunting.

Kelly and Todd’s (1988) arguments, as detailed below, are a commonly cited

iteration of the hunting specialist model. Their model assumes the Americas were

unpopulated prior to the arrival of Clovis people. While Pleistocene hunters were not

exclusively megafuana hunters, they were dependent on terrestrial fauna. Since the

fluctuating climate at the Pleistocene-Holocene boundary resulted in changes in local

14

game populations, Paleoindians were constantly moving to new environments to follow

the shifting game. Kelly and Todd contend that there was a continued reliance on

hunting because it is easier to adapt to the fauna in a new region than the flora. Instead of

being concerned with adapting to new environments, early Paleoindians would have

continued to use the hunting techniques they already knew. However, Frison (2004), who

is an experienced hunter, points out that hunters use their accumulated knowledge of the

territory as well as animal behavior to hunt successfully. Adapting to a new region as

well as new game may not be as easy as Kelly and Todd claim, especially if one

considers how integrated the animal ecology is to the vegetative cover and the

physiographic features of the landscape (Frison 2004). Kelly and Todd argue that only

after the human population increased, the climate became more continental, the faunal

population decreased, and the remaining species became more allopatric, would

Paleoindian strategies have begun to shift from the hunting specialist model.

Growing View as Generalized Hunters and Gatherers. While megafauna were

certainly exploited by Clovis hunters, Clovis-aged megafauna kill sites are less common

than other types of sites (Kornfeld 2007). Also, human involvement in some kill sites has

been overstated. Bones which have been naturally broken and scratched should be

expected at waterhole sites. Elephant bones at modern watering holes, for example, are

mixed and sometimes broken and scratched. Furthermore, natural processes can create

bone modifications that are identical to butchering by humans. Breakage and sharp

incisions on animal bones does not necessarily reflect human agency. As such, human

involvement in the breakage cannot be determined, even if stone tools were found in the

same deposits, unless the association is unambiguous and clearly indicates a behavioral

15

relationship (Haynes 1988, 2000).

Of late Pleistocene mammals, only mammoth and mastodon kill-sites are clearly

documented, merely fourteen of which are from secure contexts (Grayson and Meltzer

2002). While horse and camel bones are either as commonly or more commonly found

than mammoth or mastodons at archaeological sites, no kill-sites for these genera are

clearly documented (Grayson and Meltzer 2002; Haynes 1988). Given the visibility and

archaeological interest invested in megafauna remains, Grayson and Meltzer conclude

that the rarity of megafauna kill-sites does not result from a bias but represents reality.

Additionally, the exploitation of birds, shellfish, mammals of all sizes, and the

wide range of other species documented at a variety of Paleoindian sites (Kornfeld

2007:56) does not fit within the hunting specialist model. Diverse faunal assemblages of

a wide range of mammals, reptiles, and birds, have been documented from Clovis

contexts at a number of sites in Texas; including, Aubrey (Ferring 1989, 1990, 1995; Hall

1996), Lewisville (Stanford 1982, 1983; Stanford et al. 1995; Winkler 1982), Lubbock

Lake (Johnson 1991, 1995a, 1995b; Kreutzer 1987, 1988), and Kincaid Shelter (Collins

1990; Collins et al. 1989). Riparian animals were observed at the Aubrey and Kincaid

Shelter sites (Collins 1990; Collins et al. 1989; Ferring 1989, 1990, 1995; Hall 1996).

Extending beyond faunal remains, carbonized plant seeds in addition to fish bones were

excavated from secure geologic context at the Shawnee Minisink site in northeastern

Pennsylvania (Dent 2007:123).

Although sites with well-preserved faunal assemblages are fairly rare, other

sources of evidence can be examined as well. Reoccupation events at sites such as Gault,

meat-caching at the Sheaman site (Frison 1982), and numerous examples of lithic-

16

caching (Collins 1999b:173-177) all support a more “place oriented” lifestyle during

Clovis times than the one suggested by the hunting specialist model (Kornfeld 2007:57).

Fauna at Gault. A diverse sample of animal species of all sizes was on the menu

during Clovis times. Frogs, birds, small mammals, horse, bison, and mammoth have

been documented in the faunal record (Collins 2002). Use-wear studies of Clovis lithic

artifacts from the Gault site (discussed in further detail in the following section) support a

broad, non-specialized subsistence pattern (Shoberg 2010).

Examining Gault within its regional context, the site’s location along the Balcones

Escarpment provides access to the resources of the Balcones Canyonlands, the Blackland

Prairies, and the Oak Woods and Prairies. Megafauna populations roamed the Gulf

Coastal Plain (FAUNMAP Working Group 1994, 1996; Lewis 1988, 1994; Sellards

1940, 1952). The mammoth (Mammuthus jeffersonii) was common throughout most of

Texas while the mastodon (Mammut americanum) was restricted to the Gulf Coastal

Plain and the stream valleys on the Edwards Plateau (Lundelius 1986). The irregular

landscape and dense brush of the Balcones Canyonlands does not make it an ideal

location for large mammals (Collins 2002). It can be concluded, therefore, that Gault is

best suited for generalized hunter-gatherers and not specialized megafauna hunters.

Clovis Lithic Technology

Clovis Lithics. Clovis lithic technology is the first well described technology in

North America (Collins 1999b). The hallmark of Clovis technology is the fluted Clovis

point (Haynes 2002:1). Other artifacts from Clovis sites include: various types of

scraping and cutting tools as well as, in cases of good preservation, bone, antler, and

17

ivory tools. The technologies used to produce Clovis materials varied little throughout

the Clovis age. Bifacial flaking produced blanks, knives, adzes, preforms, and spear

points; blades detached from prepared blade cores were used as scrapers and cutting tools

(Bradley et al. 2010:1). It should be noted that Clovis blades are macroblades.

Microblade technology, a distinctly Arctic and East Asia technology, is not present in

Clovis lithic assemblages (Bever 2001; Goebel 2002; Goebel et al. 2003; Goebel et al.

2008).

The Clovis point is often considered to be equivalent with the Clovis “culture.”

In fact, many Clovis sites have been identified as Clovis solely through the association

with Clovis points. This is problematic because there is still some debate as to where to

divide Clovis and other fluted points, such as Cumberland, Vail, Gainey, Folsom, etc.

(Bradley et al. 2010:2). The Clovis point, however, represents only one aspect of a

diverse lifestyle, as evidenced from the study of other tools in the Clovis toolkit.

Studies that source the high-quality flaking materials like chert and obsidian

reveal that often these stones were procured hundreds of kilometers from the discard

location (Tankersley 2004). This supports the assumption that the tools were part of a

conveniently transported tool kit.

Lithic Insights from Gault. Conversely, recent studies of lithic material from

Gault are contributing to the developing view of Clovis people as less mobile. The Gault

site represents a camp site repeatedly used by Clovis people. The area near Gault

provided excellent access to high quality chert, water, and plant and animal food

resources (Collins 2002). High-quality chert outcropping from the Edwards Limestone

bedrock available on-site were used to manufacture 99% of the artifacts and debitage

18

excavated (Collins 2007:67).

Gault represents more than a quarry site. There are several examples of tools

being manufactured, used, re-sharpened, and finally discarded at the Gault site (Collins

2007:68). It is argued, therefore, that Clovis people were at the Gault site during every

stage lithic analysts identify in the use-life of stone tools. These observations, especially

when considered along with the interpretation that the extremely thick Clovis deposits at

the Gault site which were accumulated over extended occupational events (Collins 2002),

counters the view of Clovis peoples as only being a highly-mobile society.

The lithic assemblage from the Gault site suggests Clovis people were engaged in

a variety of domestic activities in addition to hunting or meat processing. Micro-wear

analysis on a representative sample of stone tools from Gault indicates processing and

manufacture of skin, bones, fiber, and wood (Shoberg 2010:156). Shoberg (2010:154)

also notes that “tools manufactured and used at the Gault site during the Clovis

occupation represent a complex system of strategies and decisions in regard to the

acquisition of the appropriate tool for the task at hand.”

New artifacts not previously associated with Clovis have been cataloged at Gault:

woodworking adzes, choppers, gravers, and leather punches (Bradley et al. 2010). A

small stone tool component, used for an array of domestic activities not associated with

big-game hunting, has been catalogued as well. Rather than being used as part of a

composite tool, the small tools were hand-held and used individually. Use-wear studies

indicate that only one of the examined blade/bladelets (n=6) had been used on soft animal

material. Four had been used to cut grass or reeds and the remaining two were used to

fashion bone (Bradley et al. 2010:107-113). These findings support a more diverse

19

lifeway than mobile specialized hunting could afford.

The Clovis-First Paradigm

Pre-Clovis Occupations. As more pre-Clovis sites are documented, the body of

evidence for a human presence in the Americas prior to Clovis grows. Meadowcroft

Rockshelter is a deeply stratified, multicomponent site in southwestern Pennsylvania.

The site was intermittently occupied during all the major cultural stages/periods

recognized in northeastern North America. Excavations were carefully conducted along

natural stratigraphic levels. Extensive radiocarbon dating suggests the site was occupied

by at least 14,000-14,500 calendar years ago (Adovasio et al. 1978; Adovasio et al.

1990). Critics argued that the radiocarbon dates were contaminated by “old carbon” that

was carried through the sediment by groundwater (Haynes 1980, 1987; Tankersley and

Munson 1992; Tankersley et al. 1987). Micromorphological analysis suggests

groundwater contamination is not an issue as there was no evidence of groundwater

activity (Goldberg and Arpin 1999).

The first widely accepted pre-Clovis site was Monte Verde in Chile. The Monte

Verde (MV) II camp site, excavated by a team of archaeologists lead by Tom Dillehay,

dates to 14,500 calendar years ago. A remarkably rich organic and inorganic record of

this occupational event was preserved in a peat bed formed along the banks of

Chinchihuapi Creek, with house planks, animal bone and hide, marine algae, crayfish,

berries, and charred plants providing snippet views of daily life (Dillehay et al. 1997).

The site was preserved well enough to convince a team of Clovis First proponents and

skeptics that the associations were genuine (Meltzer et al. 1997). While one team-

20

member later reversed his support (Haynes 1999), the majority of the archaeological

community now recognizes Monte Verde as a valid pre-Clovis site (Haynes 2002:18-19;

Meltzer 2009:117-129).

Additional sites are pre-Clovis contenders, as well. Paisley Cave (Oregon), Page-

Ladson (Florida), and Manis site (Washington) support an occupation of North America

by 14,600 calendar years ago (Goebel et al. 2008; Waters et al. 2011c). The Cactus Hill

(Virginia) site dates to as early as 20,000 years ago (Goebel et al. 2008; Wagner and

McAvoy 2004). Miles Point (Maryland) may date to 25,000 years ago (Lowery et al.

2010). While difficult to place within the context of known human history, possible

evidence for an occupation that may be as old as 37,000 cal. years B.P. (Bronk Ramsey

2013) is documented at Monte Verde, also known as, Monte Verde I. This occupation is

associated with three small hearths, each lined with non-local clay and associated with

flecks of charcoal, and over two dozen possibly man-made artifacts (Dillehay and Collins

1988).

As discussed in the introductory chapter, there is evidence for a pre-Clovis

component stratigraphically underlying the Clovis component at the Gault (Collins and

Bradley 2008) and Debra L. Friedkin (Waters et al. 2011b) sites. While some artifacts

excavated from strata underlying Clovis artifacts lack the technological trademarks of

Clovis knapping (Collins and Bradley 2008), there are some technological similarities

among other artifact types, especially blade and blade tools (Michael Collins, personal

communication). In the pre-Clovis levels, there are biface forms not seen in Clovis

assemblages, small bladelets that are not quite the same as those in Clovis assemblages,

and more burins compared to Clovis levels at Gault. In a pilot study conducted by

21

Jennifer Gandy for her thesis research, 100 flakes from Clovis and pre-Clovis levels were

examined. There were no intentional overshot or channel flakes in the pre-Clovis levels

as well as a higher number of biface thinning flakes (Gandy 2013). The oldest cultural

materials at Gault have been dated by OSL to at least 13,800 calendar years BP (Rink and

Collins 2013). Gault provides a unique look at pre-Clovis artifacts stratigraphically

underlying a Clovis assemblage, affording insight into the transition between

technologies.

Waters et al. (2011b) report a 20-cm-thick layer of dispersed artifacts underlying

a thin 2.5-cm-thick Clovis assemblage at the neighboring Friedkin site. Multi-aliquot

OSL dating returned an age of 14,070-18,930 calendar years BP. The artifact

assemblage, which is reported as small and lightweight, consists of bifaces, a core,

blades, and modified flake tools. Use-wear suggests these tools were utilized on hard and

soft materials.

Why the Slow Rate of Acceptance? While a pre-Clovis occupation of North

America is not universally accepted, it has gained growing support from the

archaeological community (Meltzer 2009:539-563). Approximately 40 pre-Clovis

candidates have been documented to date (Collins 2010).

The number of potential sites is partially limited by the nature of what survives

the archaeological record. Meltzer (2009:132-133) points out that population density is a

controlling determinant of the archaeological record. North America is a vast landscape,

but the initial people to walk this continent would have been a relatively small group.

The smaller and the more disperse the population, the less material is deposited for

archaeologists to discover.

22

As the age of cultural material increases, there is a growing probability that

geologic processes will obscure the archaeological record. Geological processes can

make a site hard to find by deeply burying it (depositional events) or destroying it

(erosional events) (Meltzer 2009:132-133). As a result, the odds become long against

site preservation and discovery of Pleistocene-aged cultural deposits. The lack of

evidence for human occupation of rockshelters during Paleoindian times may be due to

the degradation of rockshelters since any Late Pleistocene occupational events.

Archaeological materials may be buried under deposits from rockshelter collapse and

degradation (Collins 1991:157-175). The combined forces of low population density and

geologic processes may imply that 30,000 year old sites are approximately ten to fifteen

times less common than 11,000 year old sites (Butzer 1991). For a discussion of how

these geologic processes have affected the archaeological record in Central Texas, see

Chapter 3.

The predisposition of the archaeological community is also a factor controlling

the number of pre-Clovis candidates. Goebel et al. (2008) suggests sampling and artifact

recognition may be at the root of the scarce evidence for an occupation of the Americas

prior to Clovis. Folsom and Clovis sites provided a model that can be used to predict the

location of additional Paleoindian sites: deeply stratified river terraces, dry lake beds, and

association with megafauna bones (Meltzer 2009:91). This method ultimately resulted in

the creation of a bias for discovering kill sites, where large mega-fauna mammals were

killed and butchered by Clovis hunters, rather than “boneless” Paleoindian sites. Even

though there was a bias, the method worked and sites of comparable age were found. If

early archaeologists were to excavate below the Clovis-aged mammoth kill, however, it is

23

unlikely pre-Clovis materials would be found. Campsites are more likely to contain

stratified deposits from multiple occupational events. Kill sites often represent

opportunity and expediency rather than people returning to steady, reliable resources.

Additionally, there is a widely recognized tendency in archaeology, as explained by Al

Goodyear (in Marshal 2001), for excavations to stop once the base of Clovis has been

reached, rather than continuing until bedrock, because nothing is expected to lie

underneath Clovis deposits (Collins 1998c) .

Why, however, is the archaeological community still split on the issue almost 15

years after the publication of near-incontrovertible data on Monte Verde? Archaeology

brings a justifiable skepticism of sites older than Clovis, based on a history of

misidentified archaeological sites. Sites repeatedly have been declared the definitive pre-

Clovis site only to be rejected a few years later. Krieger (1964), MacNeish (1976), and

Morlan (1988) published lists of pre-Clovis sites, but none are considered pre-Clovis

today (Meltzer 2009:96). None of the sites from these lists, however, met all three

requirements of a secure site: indisputable traces of humans, undisturbed stratigraphy,

and secure dating. What has changed in recent years is the emergence of pre-Clovis sites

that meet the profession’s requirements and are slowly overcoming the long-standing

adherence to Clovis-First.

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3. ENVIRONMENTAL SETTING

Geoarchaeology, as described by Butzer (1982:35) “implies archaeological

research using the methods and concepts of earth sciences.” As geoarchaeological

investigations are ultimately targeted at archaeological questions, it is the intention of the

author to not only examine environmental, climatic, and landscape contexts in the region

during the Late Pleistocene and Holocene but to also describe how these factors affected

the cultural context and archaeological record on the Edward’s Plateau.

The focus of the chapter is the eastern portion of the Edward’s Plateau. The

chapter begins with a description of the modern environment; moves on to a discussion of

bedrock geology and soils development on the Plateau and along the Escarpment, and

reviews Late Quaternary paleoclimates and landscape evolution in the region. The

chapter concludes with a discussion of how geologic processes have affected the

preservation of the archaeological record in Central Texas as well as why preservation of

complete Late Pleistocene and Holocene archaeological and geologic records are rare in

Central Texas.

Site Location

The Gault site is located in southernmost Bell County, at the border with

Williamson County. Bell County is divided into two physiographic regions, the Edwards

Plateau and the Blackland Prairie, separated by the Balcones Escarpment. The western

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25

Figure 3. The natural regions of Texas.

third of Bell County is on the eastern edge of the Edwards Plateau (Figure 3), an uplifted

region of the Texas Cretaceous rock system. The Edwards Plateau is a relatively flat

elevated plateau to the west. The southeastern portion, the Balcones Canyonlands, or as

it is commonly referred, the Hill Country, is deeply eroded. The deeply incised Balcones

Canyonlands and the Lower Pecos Canyonlands rim the southern portion of the Plateau.

The Lampasas Cut Plain lies to the northeast of the Plateau (Texas Parks and Wildlife

[TPWD] 2012a). The eastern two-thirds of the county are within the Blackland Prairie;

which represents the western edge of the Gulf Coastal Plain. The Blackland Prairie is

characterized by black, calcareous, alkaline, heavy clay soils that are underlain with

Natural Regions of Texas

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26

Figure 4. Buttermilk Creek Valley.

Upper Cretaceous limestone, shales, marls, and chalks (TPWD 2012b). Gault lies about

15 km to the west of the Balcones Escarpment on the Edwards Plateau.

Gault is located in the Buttermilk Creek valley (Figure 4), near the headwaters of

Buttermilk Creek (Figure 5 and 6). The Debra L. Friedkin site is located approximately

250 meters downstream along Buttermilk Creek from the Gault site (Waters et al. 2011b).

Buttermilk Creek runs for 13 km, joining Salado Creek to the northeast and ultimately

draining into the Brazos River (Figure 7). The Gault site is roughly 800 m long and 200

m wide, covering approximately 16 ha (Collins 2002).

The bedrock of the valley is formed by Lower Cretaceous limestone with chert

nodules (Figure 8). Edwards Limestone, Comanche Peak Limestone, and Glen Rose

Limestone are represented (Barnes 1974; Michael B. Collins, personal communication).

The cultural material is found in alluvial, colluvial, and aeolian deposited sediment,

which has been subject to diagenesis, pedogenesis, and erosion, overlying the limestone

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27

Figure 5. Looking downstream along Buttermilk Creek.

Figure 6. Photo of the current excavation block taken from Buttermilk Creek.

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Figure 7. River systems near Gault. Data from USGS. Map generated by Bryan Heisinger.

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Figure 8. Bedrock geology surrounding the Gault site.

Figure 9. Sedimentary deposits at the Gault site.

Area 15

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bedrock (Figure 9).

Modern Environment

Climate. Texas is divided into Continental, Mountain, and Modified Marine

climatic types (Figure 10). Western Texas receives significantly less rain than eastern

Texas. Larkin and Bomar (1983:3) define five factors for climatic variation in Texas: it

is downwind from the western mountain ranges, which obstruct northern cold air masses;

it is adjacent to the moist air of the Gulf Mexico and the dry air of the southern Great

Plains; the Bermuda high pressure cell lies to the east; it is situated in a low lying

latitude; and there is a dramatic elevation change between the northeastern high plains

and mountains to the southeastern coastal plains. The majority of the state falls within

Modified Marine, which is also referred to as Subtropical. In Subtropical climate

regions, the onshore flow of maritime air from the Gulf of Mexico decreases in moisture

content as it travels inland and is affected by seasonal incursions of continental air. The

Subtropical climatic type has four subheadings, Humid, Subhumid, Semi-arid and Arid,

which describe the decreasing moisture content of Gulf air as it moves east to west

(Larkin and Bomar 1983:1-3).

Bell County is positioned along the boundary between Subtropical Subhumid,

defined by its hot summers and dry winters, and Subtropical Humid, characterized by

warm summers (Larkin and Bomar 1983). Typically, Central Texas alternates from wet

conditions in the spring and fall to dry in the summer and winter (Environmental Science

Institute 2012). Precipitation in Bell County averages between 81.3 to 91.4 cm. per year

with average annual low and high temperatures ranging between 9oC in January and 27

oC

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31

Figure 10. The climatic regions of Texas. Adapted from Larkin and Bomar 1983.

in July (Larkin and Bomar 1983). Central Texas is prone to drought conditions. Nearly

every month of the year, particularly between May and September, rainfall is surpassed

by potential evapotranspiration. The moisture deficit worsens when Central Texas

receives less rainfall than average (Environmental Science Institute 2012).

The area surrounding the Balcones Escarpment is subject to the highest potential

incidence of high-magnitude flooding in the United States. The escarpment receives

more rainfall, often in intense randomly distributed bursts, than the surrounding regions

(Caran and Baker 1986). The potential for flooding is particularly high between May and

July or September and October when the region is prone to large storms. During these

months, convergence between polar air masses and easterly waves occurs in the upper

Gault

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levels of the atmosphere. Polar air is typically cool, high in pressure, and low in

moisture; in contrast, easterly waves are low pressure troughs of moist warm air moving

westward (Caran and Baker 1986; Slade 1986). Additionally, the collision of moist

tropical air from the Gulf of Mexico or Pacific Ocean with southward moving cool dry

air over Central Texas results in convective thunderstorms (Nordt 1992:1; Slade 1986).

The physiographic contours of the Balcones fault zone contribute to the severity

of storms in Central Texas. The Balcones Escarpment lies at a right angle to the

prevalent winds from the Gulf of Mexico. After traveling across the coastal plain, the

moist air abruptly collides with the slopes of the escarpment. The sudden upward

movement of the air mass causes further cooling, and ultimately, triggers condensation

and precipitation (Slade 1986). The intensity of flood events in Central Texas is

heightened by rapid runoff and limited infiltration rates. Thin plant cover, exposed

limestone bedrock, and steeply sloping drainage basins are contributing factors (Caran

and Baker 1986; Nordt 1992:1). The soils on the Coastal Plains, in comparison, have low

infiltration rates (Caran and Baker 1986). In addition to natural factors, urbanization

contributes to flooding (Caran and Baker 1986).

Hydrology. The Edwards Aquifer is a cavernous limestone system on the

Edwards Plateau, neighboring the Balcones Fault Zone. The aquifer extends over 400

km between Val Verde County and Bell County. The majority of groundwater beneath

the plateau runs along the regional dip of the aquifer to the southeast, although a portion

of the water travels to the more permeable discharge points to the northeast. Some of the

groundwater in the Edward Aquifer discharges through springs and seeps to feed surface

streams; including, for example, the headwater streams in the Nueces, San Antonio,

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Guadalupe, and Colorado River basins (Woodruff and Abbott 1986b).

Buttermilk Creek is a perennial spring-fed second- to third-order stream. It has a

drainage area of 43 km2. The stream has a relatively low sinuosity of 1.26 and a rather

steep gradient of 8.5 m/km. Overall, Buttermilk Creek has a straight channel with a few

sections that switch to either a meandering or braided channel. The meandering sections

have point-bar formations. The outer bends of the meander is confined by bedrock bluffs

or colluvial slopes. The braided sections split into two or more channels that are

separated by mid-channel bars (Gibson 1997:39).

Flora. Texas is divided into eleven natural regions by Diamond, et al. (1987).

Gault is located on the eastern portion of the Edward’s Plateau vegetation region, near the

border with the Blackland Prairie. Both the Wilson-Leonard and Gault sites, however,

while formally defined as belonging within the Edward’s Plateau vegetation region, have

all the attributes of the Balcones Canyonlands vegetation region (Collins 2002).

Vegetation distribution is dependent on climatic, topographic, and soil interactions. The

central and western Plateau are xeric (dry) while the Balcones Canyonlands and

Lampasas Cut Plain are mesic (moist). On the eastern Plateau, trees and woodland

vegetation, such as the ashe juniper, are confined to slopes and canyons (Rinksind and

Diamond 1986; TPWD 2012c). The flatter Lampasas Cut Plain to the north is grassier

than the Canyonlands (Rinksind and Diamond 1986). Before modern and historic factors

altered the vegetation, the Texas Hill Country was a grassland savannah with numerous

species of forbs, midgrasses, and tallgrasses. The savannah was maintained through

grazing by bison and antelope as well as frequent range fires (TPWD 2012d). The

grassland was dotted with occasional clumps of live oaks (TPWD 2012d). Native

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34

Americans living in central Texas subsisted as hunter and gatherers (Collins 2004),

exploiting yucca (Yucca spp.), wild onion (Allium spp.), little leaf walnut (Juglans

microcarpa), and other plants on the Edwards Plateau (Dering 2005). Agriculture was

not adopted until the Late Prehistoric period in Central Texas with the introduction of

tropical cultigens, and even then, it was not of integral importance (Collins 2004).

After European settlement, which brought fences, cows, sheep, goats, and the

control of fire, the grassland morphed into a brushland dominated by poor quality

browse, forb, and grass plants. Ashe juniper, undesirable to both domestic livestock and

deer, subsequently spread unchecked throughout the Hill Country (TPWD 2012c) to

replace many deciduous trees and ultimately decreased plant species diversity. The

change in vegetation cover resulted in increased soil erosion (TPWD 2012d). Similarly,

the Blackland Prairie to the east of the Balcones Escarpment was historically a tall-grass

prairie; however, it is now used for agricultural enterprises and few remnants of the

original prairie remain (TPWD 2012c).

Fauna. Blair (1950) proposed seven biotic provinces to describe the distribution

of fauna in Texas (Figure 11). Gault lies on the boundary between the Balconian and

Texan provinces. This system was revised by Davis and Schmidly (2004) into four

faunal regions (Figure 12). In this classification, Gault lies on the border between the

Plains Country and East Texas. The mammal species listed by Davis and Schmidly

(2004:11) as occurring principally in the Plains Country are entirely rodents. This list

includes, among others, a squirrel, several pocket gophers, and a couple of mice. The

Plains have the fewest number of unique elements in the mammal fauna of any region in

Texas. The list of mammals occurring primarily in East Texas (Davis and Schmidly

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35

Figure 11. Blair’s biotic provinces of Texas. Modified from Blair 1950.

Figure 12. Faunal Regions of Texas. Modified from Davis and Schmidly 2004.

Gault

Gault

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2004:11-12) is more diversified and includes a species of shrew, a pair of bats, a rabbit,

and a couple of squirrels. These mammals are partial to the deciduous forests and coastal

prairies of the southeastern United States.

Many species of mammals are, or once were, distributed throughout the state

(Davis and Schmidly 2004:8-9). The larger animals include bison (Bos bison), white-

tailed deer (Odocoileus irginianus), bobcat (Lynx rufus), mountain lion (Felis concolor),

black bear (Urus americanus), coyote (Canis latrans), Virginian opossum (Didelphis

virginana), common raccoon (Procyon lotor), and the American beaver (Castor

canadensis). The smaller animals include the Eastern Cottontail (Sylvilagus floridanus),

Black-tailed Jackrabbit (Lepus californicus), Hispid Cotton Rat (Sigmodon hispidus), as

well as several species of mice and bats.

Relationship between site setting and cultural history at Gault. The Gault site is

located in an ecotonal setting (Collins 2002). Prehistoric people living here would have

been able to take advantage of the resources of the coastal plain as well as the Edwards

Plateau. These regions vary in terms of soils, geology, plants, animals, and climate. The

site is positioned along the border between the Balconian and Texan biotic provinces

(Figure 11), between the Plains and East Texas faunal regions (Figure 12), and between

the Subtropical and Subhumid climatic regions (Figure 9). Additionally, as the hard

Comanche Peak Limestone and permeable Edwards Limestone outcrop within Buttermilk

Creek valley (Figure 8), springs from the Edwards Aquifer discharge here.

The environment of the canyonlands is significant to the cultural history at the

Gault site. The Balcones Canyonlands is an ideal place for a hunter-gatherer to be, as it

provides easy access to the mesic environment of the canyons and the xeric environment

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on the plateau. Streams cutting through the Edwards limestone create contrast between

plateau surface and canyon lands. The Plateau surface has rocky soil and high rates of

runoff, so the water flows into the canyons. The Plateau has a semi-arid environment

with drought resistant vegetation, such as live oak or juniper, while the canyons have

deciduous trees (Collins 2002). Cultigens and horticulture were not adopted until the

Late Prehistoric period along the Balcones Escarpment (Collins 2004). The environment

of Central Texas has high variability in temperature and rainfall. Hunting the highly

adapted animals in the area or gathering plant materials from the xeric or mesic

environments provided a wider food resource base than agriculture alone could provide.

Bedrock Geology of the Balcones Escarpment and Edwards Plateau

The Cretaceous System. Retreat of the seas during the late Jurassic Period left the

North American continent almost entirely dry by the end of the Jurassic 145.5 Ma.

During the early Cretaceous, the Arctic, Pacific, and Gulf seas were advancing from the

south and east across western North America (Adkins 1981:260). The maxima of the

advancement during the Eagle Ford and Austin stages mark the last major epicontinental

marine invasion. The seas were regressing gulfwards by the end of the Cretaceous 65.5

Ma (Adkins 1981: 259-261).

The Cretaceous system in Texas records the transgression and regression cycles

of the marine shorelines of these seas. Lithologic facies correspond to the environment

of deposition. Marginal systems are represented by sandy or conglomerate sediments.

Deposits from the coastal waters, or the neritic zone, include shale, clay, marl, chalks,

limestones, and reef coquina (Adkins 1981:261). While no section represents the entire

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Cretaceous system, the combined maxima thickness of Cretaceous formations is

estimated to be 15,500 feet (Adkins 1981:260).

Geology of the Balcones Escarpment. The Balcones Escarpment is the dominant

expression of the Balcones fault zone, which is a series of en echelon, normal faults. As

a result of this tensional structural system, Upper Cretaceous claystones, chalks, and

marls to the east have been downthrown relative to Lower Cretaceous limestones to the

west. The fault zone is a surface expression of the Ouachita orogen that extends from

the Ouachita Mountains in southeastern Oklahoma to the Rio Grande in far west Texas.

The Ouachita orogen runs deep into the crust (Woodruff and Abbott 1986a). The

Balcones fault zone developed on the hinge zone of the Ouachita orogen. The

continental interior is a stable craton. The Gulf Coast Basin, however, is still being

downwarped (Foley and Woodruff 1986). Typically considered as forming in the

Miocene, the tectonic events which created the Balcones Escarpment may have begun in

the Cretaceous instead (Woodruff and Abbott 1986a).

Geology of the Edward’s Plateau. As a result of the formation of the Balcones

Escarpment, Lower Cretaceous limestones were uplifted (Woodruff and Abbott 1986a).

The limestone rocks forming the Edward’s Plateau have been weathered differentially.

The younger rocks to the east are less eroded while the older rocks to the west are highly

eroded. The erosion to the west creates the topography of the Balcones Canyonlands that

consists of steep canyons, narrow divides, and high-gradient drainages (Rinksind and

Diamond 1986).

The Lampasas Cut Plain lies to the northeast of the main portion of the Edwards

Plateau and is underlain by the older Lower Cretaceous rocks in the region. Additionally,

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patches of dolomite and marl crop out. Chert is restricted to the Edwards Group deposits

and secondary gravels. The Llano Uplift is an intrusive body of Precambrian rocks

including granite and schist that lies in the center-eastern part of the Plateau. It is

stratigraphically underneath early Paleozoic sedimentary rocks including limestone,

dolomite, sandstone, siltstone and shale that are being eroded to expose the underlying

Llano Uplift (Rinksind and Diamond 1986).

Soils of the Edwards Plateau

The Balcones Escarpment not only divides the geology between the Edwards

Plateau and the Blackland Prairie, but the soils as well. The soils overlying the Lower

Cretaceous bedrock of the Edwards Plateau are thin and gravelly compared to the thick

Blackland Prairie soils that developed from the Upper Cretaceous marl bedrock. A wide-

variety of soil types have developed on the Edwards Plateau due to its hilly landscape and

variation. Upland soils developing in place on the limestone or caliche slopes are

shallow and gravelly. These soils are generally classified as Inceptisols (Rinksind and

Diamond 1986). Typically seen in humid and subhumid regions, Inceptisols are depleted

in bases or iron and aluminum while retaining some weatherable minerals. Inceptisols

lack illuvial horizons enriched by silicate clay or a mixture of aluminum and organic

carbon (USDA and NRCS 2011). In broad valleys and on flats, the upland soils are

thicker and are typically classified as Mollisols (Rinksind and Diamond 1986). Mollisols

are dark colored surface horizons that are base rich (USDA and NRCS 2011). Vertisols

also occur throughout the Plateau, especially in the east and northwest. Vertisols are

dominant on the Blackland prairie (Rinksind and Diamond 1986).

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Soils at the Gault and Friedkin Sites. The soil on the uplands surrounding the

sites is the Georgetown clay loam (Figure 13 and Table 1) (USDA and NRCS 2012).

This soil forms along ridges, is well-drained, has a maximum calcium carbonate content

of 5%, and is 50 to 100 cm deep before hitting bedrock. This soil contrasts sharply with

the shallow, gravelly soils typical of uplands on the Edwards Plateau. The deposits

within the valley are comprised of Lewisville silty clay and Frio silty clay. Both of these

silty clays form along floodplains, are well-drained, have a maximum calcium carbonate

content of 40%, and are more than 2 meters thick (USDA and NRCS 2012). The Frio

series is placed within the fine, smectitic, thermic Cumulic Haplustolls taxonomic class

while the Lewisville series is classified as a fine-silty, mixed, active, thermic Udic

Calciustolls. Both of these series are Mollisols (Soil Survey Staff 2013).

The current excavation block at Gault and the neighboring Debra L. Friedkin site

are situated within the Lewisville silty clay found within the floodplain deposits from

Buttermilk Creek (USDA and NRCS 2012). While the Frio and Lewisville series are

classified as Mollisols by the Soil Survey Staff (2013), the clay-rich sediments have

developed into a weakly expressed Vertisol at both sites. The defining characteristics of

Vertisols -- cracks, slickensides, and micro high/micro low topography (Graham 2006;

Schaetzl and Anderson 2005) -- have been observed at Gault and Friedkin (Hildebrand et

al. 2007; Waters et al. 2011b; see descriptions in Appendix A).

Late Quaternary Environmental History and Landscape Evolution in Central Texas

For the last 1.8 million years B.P., we have been in the Quaternary Period. The

Quaternary Period is divided into the Pleistocene (1.8 million to 11,650±99 years B.P)

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Figure 13. Soil map of area around the Gault site. Area 15 is circled in yellow. From USDA and NRCS (2012).

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Table 1. Legend for map unit symbols in Figure 13. From USDA and NRCS (2012).

Bell County, Texas (TX027)

Map Unit Symbol Map Unit Name Acres in AOI Percent of

AOI

ErB Eckrant-Rock outcrop complex,

1 to 5 percent slopes

2.9 1.2%

Fs Frio silty clay, 0 to 1 percent

slopes, frequently flooded

3.6 1.5%

LeB Lewisville silty clay,


28.2 11.5%

LyB Georgetown clay loam,


202.8 82.7%

REF Real-Rock outcrop complex,

12-40 percent slopes

7.3 3.0%

W Water 0.4 0.2%

Totals for Area of Interest 245.2 100.0%

and Holocene epochs (11,650±99 years B.P. to present) (USGS Geologic Names

Committee 2007; Walker et al. 2009). Global sea level and Earth’s climate have

fluctuated during this time. At the time of the last Glacial Maximum around 23,000 years

ago, global sea level was about 125 meters lower than today.

The earth’s climate has, on average, been warming and drying since the Last

Glacial Maximum (Poore and Williams 2011). This trend, however, is not steady as the

Earth experiences climatic fluctuations. For example, the Younger Dryas was a

geologically brief period of cold and dry climatic conditions between 12,900-11,700

years BP (Holliday and Meltzer 2010) that followed the warm and moist Bolling-Allerod

interval from 14,700-12,900 years BP (Crusius et al. 2004). Antevs (1955) proposed the

term Altithermal to describe a period of increased temperatures and aridity between

7500-4000 years BP. Recent studies indicate that the Holocene climate, and the manner

in which the Altithermal was expressed, varied regionally (Dean et al. 2002; Meltzer

1999). Meltzer (1999) suggests that temperatures and aridity increased along a north-to-

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south gradient on the Great Plains in the Middle Holocene, with pronounced drought

conditions on the Southern High Plains. Consequently, warm weather C4 short grasses

dominated the landscape (Meltzer 1999; Nordt et al 1994).

Paleoclimates, or past climates, can be reconstructed through studies

incorporating the following analyses: soils stable isotopic, pollen and plant macrofossil,

faunal vertebrate and invertebrate, and geomorphic. The following discussion will be

drawn from studies examining climatic changes on the Edwards Plateau during the Late

Pleistocene and Holocene. OxCal 4.2 IntCal 09 curve (Bronk Ramsey 2013) was used to

calibrate all uncalibrated radiocarbon dates referenced in the following discussion.

Stable Isotopic Analyses. Vegetation composition is approximated in

paleoenvironmental studies through stable isotopes of carbon and oxygen. In higher

plants, there are three photosynthetic pathways for the metabolization of carbon dioxide

within the plant: the C3 pathway, the C4 pathway, and the crassulacean acid metabolism

(CAM) pathway. The type of photosynthetic pathway a plant species possess is related to

the climate in which it lives. Plants with the C4 pathway are adapted for lower carbon

dioxide concentrations, higher temperatures, and less moisture than C3 plants. CAM

plants are adapted for water-limited habitats (Ehleringer and Monson 1993). The

majority of plant species have the C3 photosynthetic pathway. All forest communities

and most temperate zones are dominated by C3 plant species. Warm and sunny semiarid

environments, like grasslands, savannas, and deserts, are preferred by C4 plants (Smith et

al. 1979).

Nordt et al. (1994) conducted a study on the stable carbon isotopes of organic

carbon in alluvial deposits and soils along three drainages at the Fort Hood Military

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Reservation in Central Texas. The ratio of C3 to C4 plant biomass production has varied

over the course of the last 18,000 cal. years B.P. These variations appear to be responses

to climatic fluctuations, and therefore, were used to infer temperature and moisture

compared to modern populations. In modern deposits, C4 grasses comprise 65 to 70% of

the sample. Using this as a baseline, higher percentages of C4 in older deposits were

classified as warmer and drier, lower percentages of C4 as cooler and wetter, and

comparable percentages as transitional.

C4 plants made up 45 to 50% of the vegetative biomass of Late Pleistocene

deposits, suggesting the coolest and wettest conditions in the last 18,000 cal. years B.P.

occurred at this time. The vegetative biomass in alluvium deposited between 12,700-

8800 cal. years BP was composed of 65-70% C4 grasses. This time frame is interpreted

as a transitional period where the climate was slowly shifting to drier and warmer

conditions. Between 6800-5700 cal. years BP, C4 began to dominate the vegetative

biomass as percentages rose as high as 95%. This period is interpreted as representing

the Altithermal in Central Texas. The percentage of C4 grasses decreased to 65-70% by

4500 cal. years BP, which is the same as the transitional early Holocene period. Except

for a possible brief increase in C4 percentages signaling a return to warmer, drier

conditions 1900 cal. years BP, Central Texas has remained in a transitional period to the

present day (Nordt et al. 1994).

Nordt et al. (2002) conducted another study examining stable carbon isotopes of

organic carbon, this time along the Medina River in South Central Texas. Variations in

C4 plant production were correlated with major meltwater pulses at the end of the

Pleistocene. C4 plant productivity decreased following two well-documented glacial

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meltwater pluses at ~18,000 cal. years BP and 14,000 cal. years BP, indicating a drop in

temperature. The addition of glacial meltwater to the Gulf of Mexico decreased the

surface-water temperature, and correspondingly, lowered land surface temperatures in

Texas. Between 12,700-11,400 cal. years BP, the percentage of C4 increased, suggesting

a warm interval after glacial meltwater was diverted away from the Mississippi River.

This period correlates to the Younger Dryas. In contrast to being a cold period in the

Northwest, the Younger Dryas in Central Texas was a period of increasing temperature

and enhanced summer monsoonal rainfall. As meltwater flow diminished, C4

productivity increased through the Holocene. There were peaks in C4 productivity at

4500 and 1800 cal. years BP, suggesting warm intervals. This study yielded results

similar to Nordt et al. (1994).

Cooke (2005) investigated soil development and erosion on the Edwards Plateau

by examining stable carbon, oxygen, nitrogen, and strontium isotope data measured on

sediments and fossils from Halls Cave in Kerr County, Texas. Cave deposits contain

remnant soils that have been eroded from upland sources. Cooke (2005) observed that

strontium isotope composition of modern soils on the Edwards Plateau was related to soil

thickness. Thin soils have a low 87

Sr/86

Sr ratio, like the underlying limestone bedrock,

while thick soils have a higher 87

Sr/86

Sr ratio, like silicates derived from old continental

crust rocks. Expecting the 87

Sr/86

Sr ratio of plants and animals to reflect the environment

in which they lived, she conducted an analysis of strontium isotopes from hackberry

seeds and mammal bones at Hall’s cave. Strontium isotope results suggest that soil

thickness peaked at ~2m and that soil depth decreased with time at a rate of ~11 cm/ka

between 21-5,000 calendar years BP until becoming the shallow soils present today.

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Stable carbon, oxygen, and nitrogen isotope compositions of fossils and sediments

reflect increased aridity and seasonality of precipitation between 17,000 to 13,000

calendar years B.P. Increased aridity, temperature, and seasonality of precipitation have

been suggested (Blum et al. 1994; Toomey et al. 1993) as the cause for the massive soil-

erosion event on the Edwards Plateau.

Pollen Analyses. An analysis of pollen records from Boriack bog in Central

Texas by Bryant and Holloway (1985) yielded a similar climatic chronology to the one

proposed by Nordt et al. (1994). The deposits in Boriack bog, however, are poorly dated.

The presence of pollen from trees that grow in cool summer environments at Boriack bog

in Central Texas document cooler and wetter climatic conditions during the full-glacial

between 26,000 and 16,800 cal. years B.P. (Bryant and Holloway 1985). Between

16,800 and 12,400 cal. years B.P., an increase in grass pollen at Hinds Cave suggests

higher temperatures and less moisture than during the full-glacial (Bryant and Holloway

1985). The trend for increasing grass species begins around 12,400 years B.P. at Boriack

bog (Bryant and Holloway 1985). At 9500 to 6800 cal. years B.P. pollen record suggests

an increase of xeric plant species near Hinds Cave (Bryant and Holloway 1985). Pine

pollen and grasses that grow in cooler conditions began to appear around 1800 cal. years

B.P, suggesting cooler and moisture conditions (Bryant and Holloway 1985). Between

1800 and 600 cal. years B.P. oak-woodlands developed in east-central Texas (Holloway

et al. 1987).

Bousman (1998) reexamined pollen data from Boriack and Weakly bogs in

Central Texas. Boriack bog contains pollen dating to approximately 19,500 year BP.

Weakly bog contains pollen data from the last 3100 years. After determining a

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deposition rate for the bog sediment from radiocarbon assays, the age of intervening

strata was calculated. Nickels and Mauldin (2001) re-examined data from Patschke Bog

(Camper 1991), which is located near Boriack bog, to identify shifts in grass pollen

frequencies. Patschke Bog contains a continuous, well-dated sequence for the last 20,000

cal. years BP.

Numerous shifts between forest, woodland, and grassland plant communities were

identified through fluctuations in the percentage of arboreal to grass pollen through time.

Higher levels of arboreal pollen are interpreted as representing cooler and moister

climatic conditions and increased arboreal cover. There is a general agreement between

the results provided by Bousman (1998) and Nickels and Mauldin (2001). Grassland

communities were identified by Bousman (1998) during the Last Glacial Maximum,

between 18-14,000 cal. years BP, between 11,300-10,100 cal. years BP, and between

9000-1800 cal. years BP. Nickels and Mauldin (2001) identified grassland environments

between 20-18,500 cal. years BP. There was an increase in grass pollen at 15,500 cal.

years BP. Much of the middle Holocene was warm and dry, although there was a brief

return to mesic conditions between 6800-5700 cal. years BP. After environmental

conditions were fairly dry between 920-670 cal. years BP, Central Texas has been in a

mesic interval for the last 670 cal. years.

A comparison of arboreal and grass pollen frequencies between the Pleistocene

and Holocene reveals contrasting plant communities with distinctly different structures.

While no modern analogs for Pleistocene plant communities are present in Texas today,

Bousman suggested the Pleistocene was marked by oak and pine parklands, a thinly-treed

grassland, with a greater arboreal diversity than Holocene plant communities. In the

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Holocene, however, there appears to be no correlation between arboreal and grass pollen

percentages (Bousman 1998).

Faunal Analyses. The faunal record, as well as the archaeological and

paleontological records, of the Pleistocene has been preserved in stratified deposits in

caves and sinkholes in Central Texas (Rinksind and Diamond 1986; Toomey et al. 1993).

Stratified cave fills on the Edwards Plateau, unlike those near the Pecos-Rio Grande

confluence, only contain segments of the late Pleistocene / early Holocene record. Hall’s

Cave, however, is an exception. The site contains a well-dated, continuous stratigraphic

section spanning the last 19,000 cal. years B.P., with older, still unanalyzed deposits

underneath (Toomey et al. 1993).

The microvertebrate record provides a chronological framework around which

late-glacial and Holocene environments can be reconstructed. Ground-dwelling fauna

(which included prairie dogs, pocket gophers, moles, and other burrowers) were present

in cave sediments deposited during the Late Pleistocene full-glacial environment (24-

17,000 cal. years BP); suggesting deeply weathered soils covered the upland surfaces of

the Edwards Plateau in glacial times. Additionally, animals living at Hall’s Cave during

the full-glacial period have since migrated northward. Mutual climatic range for those

species suggests temperature during the full-glacial were at least 6oC cooler during the

summer months than today (Toomey et al. 1993).

The disappearance of the masked shrew (Sorex cinerus / haydeni), which is

adapted to cooler summer localities, at 17,400 years BP suggests an increase in average

summer temperatures. The disappearance of the bog lemming (Synaptomys cooperi)

around 16,800 cal. years B.P. suggests the increasing temperatures were coupled with

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decreasing moisture content. Two thousand years after the disappearance of the masked

shrew, the cotton rat (Sigmodon hispidus) appears (Toomey et al. 1993), which prefers to

live in environments where average July temperatures exceed 24oC (Hall 1981). Toomey

et al. (1993) suggest that by 15,100 cal. years B.P. the environment was similar to

modern conditions, with summer temperatures within 2-3oC of present values.

The population of the desert shrew (Notiosorex crawfordi) increased relative to

the abundance of the least shrew (Cryptotis parva) between 14,200 to 12,400 cal. years

BP (Toomey et al. 1993). This change suggests decreases in the effective moisture as the

least shrew requires significant moisture (Hall 1981).

The soil around Halls Cave grew thinner between 12,400 to 5700 cal. years BP, as

suggested by the disappearance of the thick soil-loving prairie dogs. Additionally, a

gradual decrease in effective moistures is suggested by the gradual decrease in the

number of moisture dependent taxa (Toomey et al. 1993).

Between 5700 and 2500 cal. years B.P. there was a dry trend, peaking at 4500-

2700 cal. years B.P, as evidenced by the disappearance of environmentally sensitive taxa

with high moisture requirements, such as the eastern pipistrelle bat (Pipistellus subflavus)

and the woodland vole (Microtus pinetorum) (Toomey et al. 1993). Additionally, the

population of the moisture-dependent least shrew (Cryptotis parva) (Hall 1981) as

compared to the desert shrew (Notiosorex crawfordi) was at its lowest numbers

throughout the sequence of deposits at Hall’s Cave (Toomey et al. 1993).

The eastern pipistrelle bat (Pipistellus subflavus), the woodland vole (Microtus

pinetorum), and the least shrew (Cryptotis parva) began to reappear at Hall’s Cave

around 2500 cal. years BP, suggesting a return to mesic conditions. The population of

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the desert shrew (Notiosorex crawfordi) began to rise sometime after 1300 years B.P.,

suggesting a shift to the xeric conditions that exist in the area today (Toomey et al. 1993).

Since the Late Pleistocene, the environment of Central Texas has experienced

increased aridity, temperature, and seasonality of precipitation. Climatic fluctuations

paired with changes in vegetation cover resulted in the deflation of soils on the Edwards

Plateau. During the full- and late-glacial, open savanna or grasslands with mixed tall and

short grasses covered deeply weathered, reddish clay-rich soils. During the early to

middle Holocene, vegetation cover diminished and ground cover density decreased,

resulting in degradation of the upland soils. When the effective moisture reached its

lowest levels between 5700 and 2500 cal. years BP, short grasses and scrub vegetation

dominated the landscape. The deflation of the soils continued until the soil mantel was

nearly completely removed (Toomey et al. 1993).

Geomorphic Analyses. Nordt (1992, 1993) conducted geoarchaeological studies

on the Fort Hood Military Reserve, examining the soils and alluvial stratigraphy of eight

streams to determine the recovery potential for cultural sites in the stream terraces. Nordt

(1992) identified and correlated five stratigraphic units and three geomorphic surfaces

across the seven smaller upland drainages. A unique sequence of six stratigraphic units

and four geomorphic surfaces was identified along the larger Leon River.

The Reserve alluvium (>18,000 cal. years B.P.) is unique to the Leon River. The

five alluviums common to all streams in this study are the Jackson alluvium (~18,000 cal.

years BP), the Georgetown Alluvium (~12,700-9000 cal. years BP), the Fort Hood

Alluvium (9-5500 cal. years BP), the West Range Alluvium (4800-600 cal. years BP),

and the Ford Alluvium (600 cal. years BP to present). The ages of the alluvial units were

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determined through radiometric dating and were corrected for carbon-isotope

fractionation (Nordt 1992).

The three terraces along the upland streams were the T0, T1, and T2. The

Jackson alluvium underlies the T2. The Royalty Paleosol, which formed between 8800-

10,200 cal. years BP with landscape stability lasting no longer than 800 years, is found in

the Georgetown Alluvium. The T1, which was a composite terrace, was underlain by the

Georgetown, Fort Hood, and West Range alluvium. The Ford Alluvium formed the most

recent terrace, the T0 (Nordt 1992).

Nordt’s work at Fort Hood contrasts with Jennifer Cooke’s analysis. While

Cooke argues for a peak in soil thickness ~20,000 years ago, Nordt places the deflation of

Central Texas soils in the early Holocene. Nordt (1993) suggest widespread channel

trenching occurred sometime between 18-11,300 cal. years BP, based on the distribution

of radiocarbon ages from Fort Hood. The channel trenching caused the abandonment of

the T2 floodplain, which in turn, initiated scouring of the Holocene valley.

Subsequent episodes of channel degradation and aggradation were believed to be

consequences of the dual mechanisms of Late Quaternary climatic shifts and the

depletion of upland soils. Discontinuities at 8000 cal. years BP, 4800-4300 cal. years BP,

and 400 cal. years BP represent periods of erosion. Nordt found that valley aggradation

occurred during the middle and late Holocene, which prevented the formation and burial

of soils and long-term occupational surfaces (Nordt 1992).

Meier et al. (2013) conducted a study on deposits along a small stream on Fort

Hood. The study utilized standard soil characterization data, OSL dating, thin-section

micromorphology, carbon weight percent, δ13

C values of soil organic carbon matter, and

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bulk geochemical data. Four paleosols were identified. The paleosols indicate periods of

stability at 14,000 cal. years BP (Buried soil 4), 12,000 cal. years BP (Buried soil 3),

10,000 cal. years BP (Buried soil 2), and 8000 cal. years BP (Buried soil 1). Buried soil

3 has evidence of channel migration and/or reduction in stream competency. Buried soil

2 was deposited sometime before 13,000 cal. years BP with pedogenesis occurring

subsequently. Pedogenically altered fluvial deposits, which began to aggrade 8000 cal.

years BP, forms buried soil 1.

Meier et al.’s (2013) results agree with the climatic proxies in other Central Texas

paleoclimatic studies. Based on carbon isotopes and other indicators (Meier et al. 2013),

the Late Pleistocene in Central Texas was a period of cooler and wetter conditions. The

climatic data for Central Texas contrast with the US High Plains data, where records

suggest a cooler and drier Late Pleistocene. Increased temperatures and aridity occur

during the Holocene.

Archaeological Site Preservation and Formation Processes on the Edward’s Plateau

The resources afforded by the Edwards Plateau, and on a larger scale, Cretaceous-

aged rock systems have shaped humankind’s cultural development in the region. People

have long recognized the Cretaceous system as an advantageous region and been

attracted to it. The soil, climate, and water resources along this system provide rich

resources. In historic times, these have included farming and stock raising land, artesian

water systems, oil fields, coal, and rock and gravel quarries (Adkins 1981:259-260).

In prehistoric times, the rich resources of the lands drew Native Americans.

Native American hunter-gatherers have continuously lived in Central Texas for at least

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the last thirteen thousand years. Population trends increased with time. The cultural

record has spanned different adaptational strategies and technologies, such as the

specialized hunting of bison during the Folsom period or the use of earth ovens in the

Archaic (Collins 2004).

Cultural Remains versus the Original Cultural Component. The cultural record is

represented through the following types of sites: camp, caches, isolated artifacts,

interments, cemeteries, kill/butchery, quarry/workshop, lithic scatters, and rock art.

These types of sites are found in open, bluffline, rockshelter, and cave site settings

(Collins 2004). The site setting affects the preservation and integrity of the site. Parietal

rock art, for example only occurs at blufflines and rockshelters (see Table 2). The

preference of the painter to paint rock art in these locations affects which paintings

survive the archaeological record. Rock art panels painted in areas with dry climates are

more likely to survive than those painted in moist climates, as blufflines and rockshelters

in moist climates deteriorate more readily.

Geomorphic Processes. Archaeological sites on stable land surfaces, where there

is little erosion or deposition, will easily be found through survey methods (Waters

1992:92). The sites, however, will be open to weathering from the environment and will

not be stratified. Geomorphic processes help to preserve as well as destroy the

archaeological record. The same streams that gently deposit sediment to stratify and

protect cultural materials can scour the landscape leaving it bare. As discussed in the

previous section, climate changes affect the fluvial system and results in erosional

processes. Nordt’s (1992, 1993) work at Fort Hood and Cooke’s (2005) work at Hall’s

Cave have demonstrated that at least some of the sediment and archaeological material

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Table 2. Simplified characterization of site types and settings in Central Texas.

From Collins 2004.

Site Settings

Open Bluffline Rockshelter Cave

Camp x x x x

Caches x x x

Isolated artifacts x x x

Interments x x x

Cemeteries x x x

Kill / butchery x x

Quarry/workshop x x

Lithic scatters x

Rock art x x

deposited prior to at least 5000 years ago on the limestone uplands of Central Texas have

been scoured by erosion and/or deflated. Again, modern factors that have resulted in

increased erosion on the Edwards Plateau (vegetation change, high-magnitude flooding,

and urbanization) have likely negatively impacted the archaeological record as well.

Pedoturbation. The erosional processes discussed in the previous section are not

the only processes that cause post-depositional disturbance of archaeological materials.

Pedoturbation is the mixing of the soil (Schaetzl and Anderson 2005). The effects of

pedoturbation may be seen at the surface and within the soil (Johnson et al. 1987). It

occurs to varying degrees and extents at all archaeological sites. For example, the

burrowing animals at archaeological sites will not only disturb artifacts but size sort

archaeological materials. Artifacts smaller than the diameter of burrowing animal will

move upwards and artifacts larger than the animal’s diameter will move downward. This

size sorting occurs on large and small scales (Balek 2002).

There are several different types of pedoturbation. Johnson et al. (1987) define

ten: aeroturbation (gas, wind), aquaturbation (water), argilliturbation (shrink-swell in

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clays), cryoturbation (freeze-thaw of water), crystalturbation (growth and wasting of

salts), faunalturbation (animals), floralturbation (plants), graviturbation (mass wasting),

impacturbation (comets, meteroids), and seismiturbation (earthquakes). While

aeroturbation, cryoturbation, crystalturbation, impacturbation, and seismiturbation may

not be major considerations at archaeological sites in Central Texas, the other forms of

pedoturbation should not be ignored. The following are brief examples of sources for

pedoturbation in Texas.

Springs, a common occurrence on the Edwards Plateau (Woodruff and Abbott

1986b), cause aquaturbation. Springs offer fresh water, plant resources, attract animals,

and were an attractive location for prehistoric people. Springs are dynamic. Not only are

sediment and other material being churned close to the source but spring morphology can

change through time. It is clear that aquaturbation occurs at springs. The slopes adjacent

to the spring -- or less active areas of the pond and channel system -- commonly provide

archaeological sites in primary context (Waters 1992:216-219). As discussed later in this

chapter, springs at the Gault site and have minimally affected Area 8 (Alexander 2008;

Luchsinger 2002).

Argilliturbation is the disturbance caused by the shrink-swell activity in clays.

Some soils experience expansion when wet and shrinking when dry. When the soil

becomes wet and swells its fabric shears upward along slickensides. This shearing moves

subsoil material up the profile. After the soil dries and shrinks, cracks form. This

“shrink-swell” is particularly strong in clay-rich soils with a high percentage of smectite

(Graham 2006), because of its high coefficient of linear extensibility (Schaetzl and

Anderson 2005).

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Soils that are defined by pedoturbation (Schaetzl and Anderson 2005), with the

highest degree of shrink-swell, are termed Vertisols (Graham 2006). There are several

sources of potential disturbance of the archaeological record by Vertisols. Artifacts may

be preferentially sorted from small to large (bottom to top) by the falling of artifacts into

the cracks created by Vertisols. Additionally, Vertisols often possess gilgai, which are an

assemblage of depressions and highs created though argilliturbation (Schaetzl and

Anderson 2005). Artifacts may be redistributed to reflect this micro-high / micro-low

topography. Finally, Vertisols experience self-mulching, where cobbles and other

material are removed from depth and translocated to the surface (Wilding and Tessier

1988). Artifacts may be carried to and deposited on the surface through the Vertisol’s

self-mulching process (Graham 2006; Schaetzl and Anderson 2005; Wilding and Tessier

1988). The degree of pedoturbation that occurs within a Vertisol will increase with time.

All archaeological sites are subject to disturbance through animals

(faunalturbation) and plants (floralturbation) to varying degrees. Many of the mammal

species listed by Davis and Schmidly (2004:11-12) as common to the Plains, East Texas,

or throughout Texas are avid diggers; including, numerous species of pocket gophers and

mice, the Hispid Cotton Rat (Sigmodon hispidus), prairie vole (Microtus ochrogaster),

common gray fox (Urocyon cinereoargenteus), and others. These animals introduce the

potential for the disturbance of archaeological sites today and in the past. Earthworms

and social insects building dens, such as the ant, have the potential to destroy sites in

Central Texas (Collins 2004). For example, Unit 3 at the Wilson-Leonard site has

extensive earthworm bioturbation. At Wilson-Leonard, intact sediment was disturbed

and noncalcified clayey soil material was calcified after passage through the worms’ gut

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(Goldberg 1998; Holliday and Goldberg 1998).

The transition of plants from a grassland savannah to a shrub environment

(TPWD 2012c) was also a shift to larger root systems, and therefore, likely increased

bioturbation. For example, tree root disturbance by bank vegetation growing near the

stream is present at the Wilson-Leonard site (Goldberg 1998; Holliday and Goldberg

1998). The ashe juniper was originally confined to the steep canyons and stream valleys

but is now growing unchecked across the Edwards Plateau (Rinksind and Diamond 1986;

TPWD 2012c). The root systems of ashe junipers are likely to be more damaging to

archaeological materials than forbs, midgrasses, and tallgrasses.

Landscape Evolution and Formation Processes within Buttermilk Creek Valley

Landscape Evolution and Alluvial History. Brandy D. Gibson (1997:39-40)

suggests the stream flow of Buttermilk Creek was significantly stronger in the past, given

that the stream is deeply incised into limestone bedrock, and on average, only occupies a

third of its valley. While the erosional nature of flash floods was documented by Gibson

during her field work (Gibson 1997:41), the stream channel does not migrate easily due

to the overall intermittent flow and low energy level of the stream. She suggests that

while the stream has experienced alternating patterns of deposition and erosion

throughout its history, the flow and hydrological regime has decreased through time.

Gibson (1997) attempts to reconstruct the alluvial history of Buttermilk Creek

through the generation of plan-view geomorphic maps and field observations to produce

a site potential model for the drainage system. Gibson describes five terraces, six alluvial

units, and one paleosol in the Buttermilk Creek drainage system. Gibson attempts to

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establish a chronology of deposition and erosion through diagnostic artifacts, only two

radiocarbon dates, and by the rather imprecise method of comparing local alluvial units

with well-dated deposits in the region by field observations alone. Gibson’s chronology

for Buttermilk Creek valley parallels Nordt’s (1992, 1993) chronology at Fort Hood.

Gibson’s (1997:76-79) chronology is as follows. The river valley was scoured

during the Late Quaternary, creating a deeply incised channel in the limestone. Gravel-

rich alluvium was deposited on top of the bedrock, possibly just prior to 18,000 cal. years

B.P. when the environment was cool and wet (Nordt et al. 1994; Nordt et al. 2002) and

depositional events, such as the Jackson Alluvium (Nordt et al. 1992), were occurring in

the area. This was followed by erosional downcutting to create a terrace and the

subsequent formation of a soil on the top of the terrace. The valley was likely stable

during the xeric episode between 18 to 14,000 cal. years B.P. The deposition of the

Roden alluvium began around 14 to 11,000 cal. years B.P. and ended around 9000 cal.

years B.P.

The deposition of the Roden alluvium was followed by a brief period of stability

around 9000 cal. years B.P., during which the Brown Paleosol developed. The deposition

of the Solona alluvium occurred sometime between 9 and 5700 cal. years B.P. There was

a brief hiatus in the xeric conditions around 6800 cal. years B.P. Once the xeric

conditions returned, downcutting and erosion began again. The development of the Lim

alluvium took place between 5700 and 2300 cal. years B.P. In contrast to the preceding

alluvial units, the Lim alluvium accreted during a flashy, episodic hydrological regime

with coarser sediment. Downcutting and the subsequent deposition of the Eden alluvium

occurred sometime after 2300 years B.P., possibly around 900 years B.P. The Eden

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alluvium, like the Lim alluvium, is characteristic of an episodic hydrolic regime. The

development of the modern floodplain and the accretion of the Adams alluvium began

shortly after the deposition of the Eden alluvium.

Once Gibson determined the alluvial history for Buttermilk Creek landforms, she

concludes that the preservation of archaeological sites would be low due to the erosive

nature of flash floods in the valley. She comments, however, that areas containing dated

alluvial deposits, such as the archaeological sites previously documented in the valley,

have a high potential for preservation. Gibson also extends her research beyond the

confines of the Buttermilk Creek valley by examining the effect climatic change has had

upon small drainage systems in Central Texas. Her observations suggest that Buttermilk

Creek valley fits the regional pattern.

Gibson, unfortunately, was unable to visit the Gault site during her thesis research

as an agreement with the landowners could not be made. Simply based on the presence

of Paleoindian materials at Gault (Collins et al. 1992), Gibson believes the site is

contained within the Roden alluvium.

Site Formation Processes. Heidi M. Luchsinger and Dawn A. J. Alexander

conducted studies examining the degree of post-depositional disturbance at Area 8, which

is also termed the “Lindsey Pit.” Luchsinger (2002) explores the formation of calcium

carbonate nodules, groundwater impact, post-deposition processes (namely bioturbation),

and archaeological evidence at the Gault site through a micromorphological study. Based

on the results of her analyses, Luchsinger (2002:104-107) makes several conclusions:

(1) The formation of calcium carbonate nodules is primarily pedogenic, with a

few lithogenic carbonate nodules. The increase in calcium carbonate with depth reflects

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the age of the deposits. The morphology of the carbonates observed in the field and thin

section matches the criteria established by West et al. (1988) for pedogenic carbonate.

Additionally, the alluvial sediment source for each unit remains the same throughout the

profile, yet the percentage of calcium carbonate fluctuates through the profile. This

suggests variations between units reflect weathering by leaching occurring during

pedogenesis. Finally, unlike groundwater carbonates which tend to be coarser grained

and fill void spaces, the nodules from Area 8 are micritic with many of the original

silicate grains having been forced apart.

(2) The groundwater level has fluctuated significantly through time, negatively

impacting the preservation of organics. Redox features were visible in thin section in

nearly every unit from Area 8. Redox features and pedogenic calcium carbonate are in

more advanced stages of formation within Unit 3a, which is the lowermost unit to contain

archaeological material.

(3) The micro-bioturbation evident in all stratigraphic units dispersed the

charcoal and organic matter fragments as well as blurred the cultural and stratigraphic

horizons. Plant material (namely roots) and evidence of small animal activity (by

earthworms and insects) were found in micromorphological samples throughout the

profile. Excavations at Area 8 did not yield macro-organic material. Micromorphology

revealed that organic matter and charcoal are present but these materials have been

broken into fine particles dispersed through the matrix, suggesting organic material and

charcoal were fragmented by organisms in situ. Luchsinger attributes the difficulty in

seeing distinct occupation surface and clear boundaries between stratigraphic units to

micro-bioturbation.

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(4) The Clovis period at Gault, like other areas in North America, was a period of

low precipitation and periodic drought. The predominantly alluvial sediment at the

Gault site contains silt-sized aeolian quartz dust. The quartz grains are not derived from

the limestone bedrock of Buttermilk Creek valley. Without a local source for the quartz,

Lushsinger attributes the grains to an aeolian source. Luchsinger additionally uses the

fluctuations in intensity of quartz grains between sediment units as a proxy for

environmental change. The basis for this assumption is that in drier periods, vegetation

cover decreases and wind erosion increases. This indicates that at the time of Clovis, the

environment at Buttermilk Creek valley was subject to periodic drought. The decrease of

the aeolian quartz is interpreted as an increase in moisture sometime after 12,900 years

ago. This moisture increase correlates with the Younger Dryas, which was a period of

cool and moist conditions in Central Texas (Nordt et al. 1994) unlike the cold and dry

conditions found elsewhere in North America (Holliday and Meltzer 2010). The Archaic

deposits contain an increased percentage of aeolian quartz as compared to Late

Paleoindian deposits, suggesting a return to drier conditions throughout the Archaic.

Additionally, the iron-staining of calcium carbonates extends throughout the

nodules in Archaic-aged deposits, while the staining is only found in the core of nodules

from Paleoindian-aged deposits. Calcium carbonate nodules with fairly homogenous

staining are interpreted as forming during drier periods. Consequently, Luchsinger

describes the entire Archaic period as being drier than the Clovis or Late Paleoindian

periods.

Alexander (2008) conducted an artifact orientation analysis and a re-fit study.

Vertical and horizontal relationships were studied to ascertain if secondary displacement

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occurred. Since natural agents, such as stream action, pedoturbation, and bioturbation,

may have displaced artifacts from their original position within the Clovis component, a

spatial analysis was conducted on the artifacts to determine if secondary displacement

occurred. Long axis orientation and degree of dip were examined to determine the

presence or absence of stream alteration. The results of the orientation analysis did not

find non-random special patterns. Non-random orientations would have been indicative

of natural agents affecting the artifacts.

Alexander (2008) identifies thirty-three groups of refitting pieces, where n=73.

All refit artifacts were contained within the Clovis levels at Area 8. Of the thirty-three

groups, twenty-two refit groups (67%) had a vertical difference of 5 cm or less between

pieces. While the maximum displacement was 20 cm, the mean displacement was 6 cm.

Five re-fit groups crossed the boundary between the two stratigraphic units within the

Clovis levels. Alexander’s spatial analysis and re-fit studies suggest that the context of

the artifacts were sound, indicating pedogenesis only minimally affected the artifacts at

Area 8.

Waters et al. (2011b) argues for the preservation of the stratigraphy and pre-

Clovis component, referred to as the “Buttermilk Creek Complex,” at Friedkin through

various lines of evidence, including site stratigraphy, lithic analyses, and multiple aliquot

OSL dates. Waters et al.’s arguments have been countered by Morrow et al. (2012), who

argue that the Buttermilk Creek Complex is a Clovis assemblage in secondary association

with dated sediments. In addition to not recognizing a significant difference between the

Buttermilk Creek Complex and known Clovis assemblages, Morrow and her coauthors

point out that the OSL dates of the sediment in the Paleoindian-aged strata are

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consistently older than the archaeological material contained there. For example, the

dates for the sediment in the Folsom and Clovis levels are around 1000 years older than

the established dates for either Folsom or Clovis.

It appears as if the microdebitage (<0.625 cm) in the Paleoindian levels at the

Friedkin site are moving downward through the cracks. For example, in the possible pre-

Clovis levels, levels 33b-34b are placed between the later (33a-33b) and earlier (35a-36a)

pre-Clovis components. The relatively low quantity of artifacts belonging to larger size

categories in levels 33b-34b suggest that levels 33b-34b may represent a short break in

occupation (Keene 2009).

Morrow et al. (2012) observes that the ratio of microdebitage to macrodebitage

consistently increases with depth. Between levels 32a and 36b microdebitage increases

from 75% to 89% of the total assemblage. Morrow and her coauthors also argue that --

despite Waters’ statement that the Vertisol developed through the mechanics model of

Vertisol formation and that this model accounts for the lack of artifact movement through

the profile at the site -- argilliturbation occurs in the mechanism model and accounts for

the self-mulching of soils and the infilling of cracks. Morrow et al. argue that, in addition

to pedogenesis, the apparent downward drift of artifacts could be the result of

bioturbation, floralturbation, or trampling from subsequent occupants.

Keene (2009) argues that the distribution of diagnostic points and calcium

carbonate distribution observed at Friedkin supports the minimal mixing of the early

Archaic and Paleoindian sediment and associated artifacts through the self-mulching

mechanism of Vertisols. Alternatively, Morrow et al. (2012) are concerned that the thin

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Folsom and Clovis horizons (each 2.5 cm thick) do not represent reality considering the

evidence for downward drift of the artifacts.

The soils in Area 15 display cracking and slickenside formation -- the unifying

feature of Vertisols -- along with microlow and microhigh topography (Hildebrand et al.

2007). The presence of an intact earth oven feature, consistent chronological order of the

artifacts, and the lack of cobbles found at the surface despite the many cobbles present at

depth call into question the strength of the self-munching process in this Vertisol.

Summary

This chapter focused on the environmental and geologic history of the eastern

Edward’s Plateau during the Late Pleistocene and Holocene. This chapter intended to

highlight the rarity of non-eroded and non-deflated sites like Gault. The majority of the

soils on the Edward’s Plateau experienced deflation or erosion that transformed them into

shallow stony soils, with little or no probability of preserving archaeological sites. Small

pockets, however, have accumulated sediments, and some have archaeological sites.

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4. METHODS

Analyses described in this chapter focus on understanding the sedimentary,

pedogenic, and post-depositional processes that have affected the geological context of

the archaeological occupations. Detailed descriptions and geologic profiles of the

sediment and soil horizons were made. Analyses were conducted on bulk soil samples to

supplement and test the observations made in the field descriptions. The analyses were

conducted with equipment available at Dr. Charles Frederick’s laboratory in Dublin,

Texas and at the Center for Archaeological Study (CAS) at Texas State University.

Field Descriptions and Profile Drawings

All field descriptions followed standard procedures outlined by the Soil Survey

Division Staff (1993). The profile was scraped with a trowel before a description was

made. Stratigraphic units, labeled numerically from the bottom to the top, and soil

horizons were assigned. The attributes of each stratigraphic unit and soil horizon was

recorded, including texture, field color, structure, consistence, the nature of the contact,

and descriptions of features such as mottles, pedogenic carbonate, or slickensides. Field

descriptions and accompanying profile drawings for stratigraphic units and soil horizons

are presented in Appendix A.

In geoarchaeological studies, field descriptions and profiles are important for the

interpretation of sedimentary, pedogenic, and post-depositional processes, as they

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document the nature of the deposit. When collaborated with laboratory results, they

allow for the more accurate correlation of sedimentary and soil units across an excavation

block. Additionally, the physical properties of the deposits are indicative of

environmental factors that were involved in the deposition of sediments and the

formation or subsequent alteration of soils.

Sample Collection

The profile wall was cleaned before collection to minimize surface contamination

from introduced particulates. Furthermore, cleaning minimized the possibility of

exposure to the atmosphere, which affects magnetic susceptibility (Nickels et al. 2001).

A total of ninety-three bulk sediment samples were collected from four columns.

One continuous column of fifty-seven samples, as well as thirty-six samples targeted at

three other profiles of interest, were collected (Figure 14-18). Starting at the bottom of

each column, samples were collected at 5 cm increments and placed in plastic bags. Each

sample had a volume of approximately 250 cm3 (10 cm wide by 5 cm tall by 5 cm deep).

The samples were labeled in numerical order. Provenience information for each sample

was recorded (see Table 1 in Appendix B).

Particle-Size Analysis

The bulk sediment samples were ground with a mortar and pestle to break up the

hard clumps of clay. The sediment was then screened through a 2 mm screen to separate

the coarse and fine fractions. A modified version of the methods outlined by American

Society for Testing Materials (ASTM 1985) was used.

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Figure 14. Locations where bulk sediment samples were collected in Columns A, B, C, and D.

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Figure 15. Column A along the west wall of the Area 15 excavation block, facing west.

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Figure 16. Column B along the north wall of the Area 15 excavation block.

Figure 17. Column C along the north wall of the Area 15 excavation block.

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Figure 18. Column D was collected from pedestaled cobbles along the east wall.

Air-dried soil samples retain varying amounts of water. Adjusting for

hygroscopic water content avoids weight errors. A 15 g portion of the fine fraction from

each sample was dried in the oven at 105oC overnight to measure the hygroscopic

correction (Pansu and Gautheyrou 2003:3).

Approximately 50 g of the fine fraction from each sample was set aside for a

hydrometer analysis. The method uses Stokes’ Law to determine the amount of silt and

clay in the sample. Stokes Law states that particles settle in water at a rate proportional

to their diameter. The differential rates at which silt and clay particles settle are used to

determine their percentages (Gee and Or 2002:269).

Stokes’ Law assumes that there is no interaction between individual particles and

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that the particles are smooth and spherical. Soil particles, however, are not smooth and

spherical, so it is assumed that the particle diameter is an equivalent rather than the actual

diameter (Gee and Or 2002:269). As to the interaction between particles, sodium

hexametaphosphate (HMP) is a dispersing agent that serves as a flocculant to separate the

individual grains. 5 mL of HMP solution (50 g of HMP to 1 L of distilled water) was

added to each of the 50 g samples. Extra distilled water was added and the sample was

stirred. The samples were soaked in the HMP solution for at least 16 hours.

The following day, a mechanical stirring device was used to disperse the sample

for 1 minute. The soil slurry was then transferred to the hydrometer cylinder and distilled

water was added to the 1000 mL mark. The cylinder was shaken, end over end, for 1

minute to loosen any material on the bottom. Once the cylinder was placed back on the

table, the hydrometer was placed into the suspension and the time was recorded.

Readings from the hydrometer, recorded to the nearest 0.5 g, were taken after 1, 3.5, 5,

15, 60, 250, and 1440 minutes.

Once the final measurement was taken from the hydrometer run, the sediment was

wet-screened through a 53 µm screen to leave only the sand and coarse silt fraction in the

screen. The remaining sand fraction was transferred to a beaker. After being decanted,

the samples were placed in the oven at 170oC overnight to dry. Once dry, the sand was

sieved with the Ro-Tap Model E Test Sieve Shaker for 5 minutes through screens stacked

in descending order at half-phi intervals ranging between -1 and 4 phi. The sand

remaining in each screen was weighed.

The coarse fraction was soaked in water overnight and then wet sieved through a

2 mm screen to ensure only the coarse fraction remained. The wet-sieved gravels were

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then placed in the oven overnight at 170oC. Once dry, the gravels fraction was sorted to

remove any cultural material, bones, calcium carbonate nodules, root casts, intact snail

shells, etc. Calcium carbonate nodules, however, were not removed from the sample

between 92.90-92.95 m or from the samples beneath 92.85 m in Columns A. Nor were

the nodules removed from samples beneath 93.00 m in Column C. The sediment beneath

these elevations was too heavily cemented by calcium carbonate. Many gravels in the

lower elevations were thickly coated by calcium carbonate.

The gravels were sieved through -5, -4, -3, -2, and -1 phi screens stacked in

descending order with the Ro-Tap Model E Test Sieve Shaker (Figure 19) for 5 minutes.

The weights of the gravels in each screen were recorded. A spreadsheet provided by Paul

Lehman, Assistant Professor at Austin Community College, was used to calculate the

percent clay, silt, sand, and gravel as well as the mean and standard deviation for each

sample.

Particle size analysis is useful in studies like this because it can reveal information

ranging from source material to depositional context. For example, mean grain size of the

particles represents the strength of the local forces affecting sediment movement (Folk

1980:3). Sorting can reveal the size range of the source material, type of deposition, and

variation in the forces that have affected sediment transport (Folk 1980:4). Particle-size

will also prove to be a factor in correlating sedimentary units across the excavation block

(Folk 1980:7).

Organic Carbon and Organic Matter Content

Soil organic matter (SOM) is “the organic fraction of the soil exclusive of

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Figure 19. Ro-Tap Model E Test Sieve Shaker

undecayed plant and animal residues” (Tabatabai 1996). Carbon, nitrogen, phosphorous,

and sulfur, along with humus and other chemical compounds, are found in SOM. Soil

organic carbon (SOC) is the carbon constituent of the SOM. The SOM content is

typically 1.7 to 2.0 times SOC content of a surface horizon and up to 2.5 times SOC

content of a subsurface horizon (Holliday et al. 2004:363-364).

Weight loss-on-ignition (LOI) and Walkley-Black were used to determine the

organic matter and organic carbon content in the soil. In the Walkley-Black method, the

organic carbon in the soil is oxidized by the addition of potassium dichromate and

sulfuric acid to the sample (Tabatabai 1996). LOI measures the weight change of a

sample after it is heated to a high enough temperature to burn off the organic matter

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(Schulte and Hopkins 1996).

Both methods are subject to error. LOI overestimates the organic matter content

because the hydrated aluminosilicates, as well as the organic constituents, will lose

weight during heating. The chemical procedure in the Walkley-Black method does not

complete the oxidation of organic C (Tabatabi 1996). Therefore, a correction factor of

1.30 was used.

For the LOI method the recommended temperature and duration varies in the

literature. The oxidation of organic C does not occur within a narrow temperature range

at which there is negligible weight loss from other minerals. At temperatures over 500oC

there is weight loss from carbonates, structural water from clay minerals, oxidation of

Fe2+

, and decomposition of hydrated salts. Heating the samples at less than 500oC avoids

this issue (Schulte and Hopkins 1996).

The selected method for the LOI procedure was adapted from Ben-Dor and Banin

(1989). For each sample, 10 g of the fine fraction was weighed and transferred to

crucibles. The crucibles were placed in the oven at 105oC for 24 hours to remove the

hygroscopic moisture and prevent the overestimation of organic C. With the hygroscopic

moisture removed the crucibles were weighed again. Next, the crucibles were transferred

to the furnace heated to 400oC. After 4 hours the crucibles were removed and weighed to

determine the weight change (Figures 20-21). Ben Dor and Banin recommend keeping

the samples in the oven for 8 hours; however, according to their results, there was only an

additional weight loss of 0%, 0.1%, 0.25%, 0.4%, 0.4%, and 0.45% for each of the five

sediment samples after the being in the oven for 8 hours as compared to 4 hours.

The Walkley-Black procedure follows the methods outlined by Nelson and

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Sommers (1996:995-996). First, 1 g of finely-ground sample was transferred to an

Erlenmeyer flask, and then 10 mL of Potassium Dichromate followed by 20 mL of

Sulfuric acid was added. The flask was agitated for 30 seconds to disperse the soil into

the solution. The sample was allowed to cool for about 30 minutes. Next, 200 mL of

distilled water followed by eight drops of o-phenanthroline indicator were added. The

solution was placed on a stir plate and titrated with 0.5 M FeSO4 until the color changed

sharply to a maroon color. A blank was prepared in the same manner but without the soil

sample.

The results were calculated according to the following formula, where the

correction factor, f = 1.30.

( )( )( )( )

At archaeological sites, SOM can be added through natural soil processes or

human activity (Holliday 2004:298). Consequently, organic matter content can be used

to trace soil development, sediment changes, and anthropogenic alteration. For example,

a criterion for the classification of O and A horizons is an accumulation of organic

material (Schoeneberger et al. 2002). Paleosols will have an increased percentage of

organic matter, as well. Alternatively, an increased percentage of SOM may be the result

of middens, agricultural activity, etc. (Holliday 2004:298).

Calcium Carbonate Content

Two methods, weight loss-on-ignition (LOI) and a chittick apparatus, were used

to determine the calcium carbonate content in the soil. In LOI, as discussed previously,

when the sample is heated to 400oC, the organic matter is converted to carbon dioxide

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and ash. In a second reaction, when heated to 950oC, carbon dioxide is evolved from the

carbonate in the sample, leaving oxide. After the samples were heated to 105oC for 24

hours and 400oC for 4 hours, the crucibles were transferred back to the furnace at 950

oC

for 2 hours (Figures 20-21). The weight change was recorded (Heiri et al. 2001).

A chittick apparatus (Figure 22) measures the amount of carbon dioxide released

when hydrochloric acid reacts with the soil (Dreimanis 1962). The methods were

adapted from Dreimanis (1962). First, 0.85 g of finely-ground sample was transferred to

an Erlenmeyer flask. Next, with the system open, the “lever” of the chittick apparatus

was raised to -10 mL. The system was closed and 10 mL of HCl was added to the

sample. The sample was agitated until the bubbles abated. After 2 minutes, the lever

was raised back up until equilibrium was achieved. The equilibrium mark was recorded

as the milliliters of gas released by the sample. The barometric pressure and temperature

of the room were recorded as well.

The percent calcium carbonate contained in the sample was determined through

the following formula, where the correction factors for pressure and temperature were,

respectively, 0.00143 and 0.00527 (Association of Official Agricultural Chemists

1950:118-119).

(

) ( ) [ (

) ( ) (

) ( )]

Calcium carbonate content, in combination with organic matter content, can be

used to trace soil development. The criteria for O and A horizons include an enrichment

of organic matter and a depletion of the mineral fraction (Schoeneberger et al. 2002).

Lower levels of calcium carbonate content suggest that the soil has been leached

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Figure 20-21. The crucibles and furnace, heated to 950oC, that were used in the

loss-on-ignition method.

Figure 22. Chittick Apparatus

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(Holliday et al. 2004:364).

Magnetic Susceptibility

Magnetic susceptibility measures the degree to which a sample is magnetizable

(Dearing 1999:4). Magnetic susceptibility can be used as a proxy indicator for rainfall

and drought cycles as well as to suggest post-depositional disturbance at archaeological

sites. Increased levels of magnetic susceptibility, for instance, suggest the presence of a

buried paleosol (Crowther 2003), a natural or human induced fire (Weston 2002),

agriculture (Holliday 2004), or other human occupational events (Batt and Dockrill

1998). Abrupt shifts in the curve demonstrate an interruption in soil development and

suggest a truncation event.

The magnetic susceptibility readings were taken at CAS. To prevent the gravel

fraction from dominating the sample, only the fine fraction was collected in 8cc plastic

paleomagnetic sample boxes. The inner dimensions of the cubes are 2 by 2 by 2 cm. The

samples were dried in the oven at 105oC overnight to correct for the hydroscopic

moisture content. The mass of each sample was recorded to the nearest hundredth of a

gram. Each cube was placed in a Bartington MS2 Magnetic Susceptibility System with a

MS2B Dual Frequency Sensor and measured on a low frequency (LF) of 0.465 kHz and

high frequency (HF) of 4.65 kHz. Measurements were recorded in SI units at a

sensitivity range of 0.1. The measurements for each sample were recorded twice on LF

as well as HF. The meter was “zeroed out” between each sample by taking air readings.

The recorded measurements were input into an Excel spreadsheet created by Dr.

Charles Frederick and provided by CAS. The average reading for each frequency was

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used to calculate the value of high- and low-frequency mass-specific magnetic

susceptibility (Xlf and Xhf). In magnetic susceptibility analyses at archaeological sites, Xlf

is the most widely used property for investigating the magnetic properties of soils and

sediments (Crowther 2003). The value of the coefficient of mass specific frequency

dependence (XFD%) was determined through the equation: XFD%=100*((Xlf-Xhf)/Xlf).

The values for frequency dependence, which did not yield informative results, are

presented in Appendix B.

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5. RESULTS

These results provide insight into the sedimentary, pedogenic, and post-

depositional processes that have affected the areas sampled. The placement of paleosols

and stratigraphic units was determined through a combination of field observations and

laboratory analyses. Field observations and analysis results suggest there are 8 soil

horizons, including two paleosols, and 10 stratigraphic zones in Area 15.

General comments

Figures 23-24 and Figures 26-28 present the results of the analyses conducted on

the bulk sediment samples (BSS) collected from Columns A through D. The numerical

data used to generate these figures is provided in Appendix B. Figures 23-24 and Figures

26-28 also display the cultural horizons and OSL dates for Area 15. Cultural horizons

were defined by the diagnostic artifacts excavated from Area 15. All OSL samples were

processed by Jack Rink from the Archaeometry and Geochronology (AGE) Laboratory at

McMaster University. The single aliquot regeneration (SAR) protocol was conducted on

a minimum of 24 aliquots to determine a final equivalent dose. The central age model

was used to determine the final mean equivalent dose (Rink and Collins 2013). The OSL

dates, which are presented in Table 3, were in the correct stratigraphic order.

The stratigraphic boundaries illustrated in Figures 23a and 26a-28a were

determined through field observations, with the few exceptions being noted in the

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Table 3. Multiple-aliquot OSL ages on quartz grains. Samples 09-01 through 09-09

were collected from Area 15. Sample 09-10 was collected from the stone pavement

at Area 12 while sample 09-12 was collected from directly beneath pavement. The

measured moisture content for all samples, when collected in April 2009, ranged

from 9 to 14% (Rink and Collins 2003).

Sample Elev.

(m)

Aliquot

Size

(mm)

Central OSL Age (ka)

10% moisture

Central OSL Age (ka)

20% moisture

Comment

09-01 94.06 3 5.82 ±0.21 6.31 ±0.22 Slow Burial

09-01b 94.06 3 5.88 ±0.20 6.36 ±0.22 Duplicate,

Slow burial

09-02 93.88 1 6.02 ±0.20 6.52 ±0.22 Slow Burial

09-03 93.64 1 6.65 ±0.23 7.20 ±0.25 Slow Burial

09-04 93.38 3 8.74 ±0.28 9.46 ±0.30 Slow Burial

09-05 93.20 1 9.22 ±0.32 9.98 ±0.34 Slow Burial

09-06 93.05 1 9.61 ±0.32 10.41 ±0.35 Slow Burial

09-09 92.28 3 12.82 ±0.41 13.87 ±0.44 Slow Burial

09-10 93.06 1 13.89 ±0.42 14.98 ±0.45 Instant

Burial

09-12 92.94 3 19.10 ±0.57 20.55 ±0.61 Instant

Burial

following discussion. In general, the results supported and supplemented the field

observations. Whenever possible, field observations and analysis results were used to

correlate the units across the excavation block.

The weight of the flakes and burned rock separated from the gravel fraction of

each bulk sediment sample is shown in Figures 24d and 26h to 28 h. These provide

insight into occupational surfaces and the presence of features where the samples were

collected.

As stated previously, the calcium carbonate nodules were not removed from the

gravel fraction of the sediment samples at 92.925 m and beneath 92.85 m in Column A as

well as beneath 93.00 m in Column D. The sediment beneath these elevations was

heavily cemented by calcium carbonate, and the gravels were thickly coated by calcium

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82

carbonate. The dominating presence of calcium carbonate in the lower elevations

affected the texture, mean, and sorting. By being thickly coated with calcium carbonate,

the gravels and other particles were categorized in the particle size analysis as having

larger diameters than they possessed in reality. That is not to say that the sediments

beneath 92.85 m and 93.00 m are fine grained; in field observations along the west wall

of the “deep excavation units,” pebbles and cobbles are documented beneath 92.35 m and

become prevalent at 92.10 m.

The LOI and chittick curves follow the same general trends; however, the chittick

method is more sensitive than LOI. Therefore, the results of the chittick method are used

to discuss calcium carbonate in Columns A through D.

Overall, the organic carbon and organic matter are weakly expressed through the

profile. While the factors of vegetation, climate, and land-use govern the organic matter

content in Vertisols (Virmani et al. 1982), these soils generally contain little organic

matter. The organic matter typically decreases with depth. The organic matter content of

Vertisols is typically less than 1.0% in India (Roy and Bard 1962) and between 0.5-2.0%

in Africa (Dudal 1965). Organic matter ranged between 2-4% while organic carbon

fluctuated between 0.63-3.21% in eight Vertisol profiles from Texas (Yule and Ritchie

1980a, 1980b). Luchsinger (2002), furthermore, provided a discussion of how the

fluctuating water table at Area 8 at the Gault site negatively impacted the preservation of

organics.

In Columns A through D, as anticipated, the loss-on-ignition (LOI) curve for soil

organic matter (SOM) is greater than the Walkley Black curve for soil organic carbon

(SOC). The SOM content is typically 1.7 to 2.0 times SOC content of a surface horizon

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83

and up to 2.5 times SOC content of a subsurface horizon (Holliday et al. 2004:363-364).

Additionally, LOI overestimate the SOM because hydrated aluminosilicates lose weight

during heating (Tabatabi 1996).

Column A

This column of samples runs from the bottom to the top of the west wall of the

excavation block (Figures 15 and 23-24). It was collected as a witness column to provide

information on the sediment and soil changes through the profile.

Texture Analysis. The general trend of Column A is to fine upward. Between

92.10-92.55 m, in sedimentary Units 1 and 2, the percentage of sand ranges from 16-

26%, which are the highest percentages in the column. Except for between 92.95-93.55

m, the percentage of sand does not exceed 9% for the rest of Column A.

Correspondingly, the silt and clay percentages between 92.10-92.55 m are low; silt never

exceeds 30% and clay never exceeds 37%. For comparison, the percentage of clay is

generally in the 50-60% range for samples above 92.70 m.

Between 92.55-92.95 m, the percentage of sand decreases to less than 9% while

the percentage of silt and clay increases. The decrease correlates with sedimentary Units

3 and 4. Sedimentary Units 5 and 6 are slightly coarser than Units 3 and 4. Field

observations placed the lower boundary of Unit 5 at 93.05 m. As a result of the increase

in the coarseness of the sediment at 92.95 m, the boundary between Units 4 and 5 was

lowered to 92.95 m. The percentage of sand increases to greater than 10% between

92.95-93.55 m. In field specimens, coarse sand and small gravels were visible in Units 5.

Additionally, as observed in field observations, Unit 5 was more friable than Unit 4. The

84

84

a. Stratigraphic Units, OSL Dates,

& Cultural Horizons

b. Texture with gravel (%)

c. Texture without gravel (%)

d. Mean & Sorting (phi)

Figure 23. Analysis results for Column A are presented in Figures 23 and 24. Numerical data can be found in Appendix B.

92.1092.2092.3092.4092.5092.6092.7092.8092.9093.0093.1093.2093.3093.4093.5093.6093.7093.8093.9094.0094.1094.2094.3094.4094.5094.6094.7094.8094.90

0 2 4 6 8 10 12Mean Standard Deviation

85

85

85

85

Xlf

CaCO3 nodules not removed from gravel

fraction

a. Calcium Carbonate (%)

b. Organic Carbon & Organic Matter

(%)

c. Magnetic Susceptibility (10-8m3kg-1)

d. Flakes & Burned Rock (grams)

Figure 24. Analysis results for Column A are presented in Figures 23 and 24. Numerical data can be found in Appendix B.

Flakes Burned Rock

92.1092.2092.3092.4092.5092.6092.7092.8092.9093.0093.1093.2093.3093.4093.5093.6093.7093.8093.9094.0094.1094.2094.3094.4094.5094.6094.7094.8094.90

0 10 20 30 40 50

Chittick LOI

92.1092.2092.3092.4092.5092.6092.7092.8092.9093.0093.1093.2093.3093.4093.5093.6093.7093.8093.9094.0094.1094.2094.3094.4094.5094.6094.7094.8094.90

0 2 4 6Walkley-Black LOI

92.1092.2092.3092.4092.5092.6092.7092.8092.9093.0093.1093.2093.3093.4093.5093.6093.7093.8093.9094.0094.1094.2094.3094.4094.5094.6094.7094.8094.90

0 40 80 120 0 15 30 45

92.125

92.225

92.275

92.375

92.475

92.575

92.675

92.775

92.825

92.925

93.025

93.125

93.225

93.325

93.425

93.525

93.625

93.725

93.825

93.925

94.025

94.125

94.225

94.325

94.425

94.525

94.625

94.725

94.850

0 50 100 150 200

CaCO3 nodules not removed from gravel fraction

86

mean supports the field observation that the boundary between Units 5 to 6 occurs at

93.20 m. The mean gradually becomes finer as it shifts from 8.72 phi at 92.975 m to

10.19 phi at 93.175 m before shifting back to 8.77 phi at 93.225 m.

Above 93.55 the percentage of sand decreases to less than 9% again and the

percentage of silt and clay increase. Continuing up the profile, the percentage of sand,

silt, and clay remains fairly consistent. There are pulses of gravel around 93.40 m, 93.95

m, and 94.15 m. The fluctuations in gravel may have been caused by a series of

overbank flooding episodes, colluvium, or were culturally introduced. There are pulses

where there percentage of silt increases at 93.30 m, 93.60 m, and 94.70 m.

Calcium Carbonate. For samples collected between 92.10-92.55 m, the

percentage of calcium carbonate exceeds 25% and spikes at 50% at 92.30 m. Above

92.55 m the percentage of calcium carbonate begins to drops before bottoming out at a

little less than 4% at 92.80 m. Between 92.95-93.20 m the carbonate percentage rises to

over 13%. There is a brief drop to 8% at 93.225 before the percentage rises to over 15%

through 93.55 m. There is a sharp drop to 1.2% at 93.775 m. After the percentage of

carbonate increases to 9% at 93.875, the percentage of carbonate steadily declines, albeit

with a few jogs, throughout the rest of the profile.

Organic Carbon and Organic Matter. While fluctuations in organic matter and

carbon are weakly expressed, the general trend is for organic content to increase up the

profile. At the base of the profile the percentage of organic carbon is 0.16% and organic

matter is 2.82% while organic carbon is 0.68% and organic matter is 5.7% at the top of

Column A. At 93.20 m and 94.40 m the organic content decreases instead of following

the general trend of increasing up the profile. There are five areas in Column A where

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87

the percentage of organics increased greater than the trend: 92.90-93.00 m, 93.45-93.65,

93.70-93.80 m, 94.05-94.20 m, and above 94.70 m.

Magnetic Susceptibility. The low frequency magnetic susceptibility readings

slowly increase up the profile to create a smooth curve. At 92.775 m the readings jump

from 7.78 to 34.79 and then return to 8.45 10-8

m3kg

-1. There are slight bumps where the

readings increase at 93.00-93.20 m and 93.70-93.80. The low frequency curve shifts at

94.125 m and 94.425 m.

Field Observations. Redox depletions with a chroma ≤2 are indicative of aquatic

conditions (Schoeneberger et al. 2002:2-14). Redoximorphic features with a chroma <2

were observed in Units 1and 2.

Artifacts. While flakes were removed from the bulk sediment samples in Pre-

Clovis, Clovis, and Late Paleoindian levels, the highest concentration of flakes was found

in Archaic levels. Burned rocks are present at 93.675 and between 93.825 and 93.925.

Nick Rodriguez conducted a preliminary study on the number and weight of

flakes beneath 93.00 m across six excavation units in Area 15 (Figure 25). Sterile dirt

underlies the pre-Clovis occupation as no flakes were excavated beneath 92.15 m. The

number of flakes dramatically increases from zero beneath 92.15 m to over 900 between

92.15-92.20 m. A sharp decrease in the number and weight of flakes between 92.25-

92.30 m suggests a break in occupation occurred during pre-Clovis times. The decrease

between 92.50-92.65 m indicates a break in occupation separates the pre-Clovis and

Clovis artifacts.

88

88

88

88

Figure 25. Number and weight (grams) of flakes under 93.00 m in Area 15. Data

courtesy of Nick Rodriguez and the Gault School of Archaeological Research.

Column B

This short column of samples was collected from the north wall of the excavation

block in the Archaic midden (Figures 16 and 26). The Archaic midden is intact along

this section of the wall and was not disturbed by looters. Collecting these samples

completes information on the midden missing from Column A.

Texture Analysis. A deposit containing whole and crushed snails is present

between 94.44 and 94.51 m. The presence of snails in a single layer across a large

section of the intact Archaic midden might not be cultural in origin but represent a death

92.00

92.10

92.20

92.30

92.40

92.50

92.60

92.70

92.80

92.90

93.00

0 300 600 900 1200 1500 1800

Elev

atio

n (

m)

Number ofFlakes

Weight ofFlakes

UNIT 1

UNIT 3

UNIT 2

UNIT 4

Break in occupation

Break in occupation

UNIT 5

Pre

-Clo

vis

Clo

vis

89


& Cultural Horizons

b. Texture with gravel (%) c. Texture without gravel (%)


e. Calcium Carbonate (%) f. Organic Carbon & Organic Matter

(%)

g. Magnetic Susceptibility (10-8

m3kg

-1)

h. Flakes & Burned Rock (grams)

Figure 26. Analysis results for Column B are presented in Figures 26a-h. Numerical data is presented in Appendix B.

0 15 30 45

94.425

94.525

94.625

94.725

94.825

94.40

94.50

94.60

94.70

94.80

94.90

0 40 80 120 160 200

0 50 100 150 200

94.40

94.50

94.60

94.70

94.80

94.90

0 5 10

Chittick LOI

94.40

94.50

94.60

94.70

94.80

94.90

0 2 4 6 8

Walkley-Black LOI Flakes Burned Rock Xlf

94.40

94.50

94.60

94.70

94.80

94.90

0 2 4 6 8 10 12

Mean SD

90

event due to a drought. Such an event occurred in the 2011 drought in Hays County (C.

Britt Bousman, personal communication). The observation that burned rocks from hearth

or oven features were separated from the bulk sediment samples in Column B directly

above and below but not in the snail deposit (Figure 26h) supports this hypothesis.

Column B remains fairly homogeneous in texture. Between 94.40-94.65 m,

however, the mean jogs back and forth as the silt and clay percentages fluctuate. Above

94.65 m, the texture remains fairly consistently around a mean of 8.87 phi, similar to

Column A.

Calcium Carbonate. The percentage of calcium carbonate is less than 10%

throughout Column B. Between 94.40-94.65 m the carbonate percentage rises from 3 to

9%. After 94.65 m, the percentage of carbonate steadily decreases to 1.8%.

Organic Carbon and Organic Matter. The general trend is for organic content to

marginally increase up the profile. At the base of the profile the percentage of organic

carbon is 1.2% and organic matter is 5.2% while organic carbon is 2.5% and organic

matter is 5.7% at the top of Column A.


increase up the profile from 112 at the base to 209 10-8

m3kg

-1 at the top. There is a shift

in the curve at 94.625 m.

Artifacts. Column B contains the largest concentration of flakes of any of the

columns. Burned rocks are present between 94.40-94.60 m.

Column C

This column of samples was collected from the north wall of the excavation block

91



& Cultural Horizons




e. Calcium Carbonate (%) f. Organic Carbon & Matter (%) g. Magnetic Susceptibility (10-8

m3kg

-1)

h. Flakes (grams)

Figure 27. Analysis results for Column C are presented in Figures 27a-h. Numerical data is presented in Appendix B.

92.20

92.30

92.40

92.50

92.60

92.70

92.80

92.90

93.00

93.10

0 10 20 30 40 50

Chittick LOI

92.20

92.30

92.40

92.50

92.60

92.70

92.80

92.90

93.00

93.10

0 1 2 3 4 5

Walkley-Black LOI

92.20

92.30

92.40

92.50

92.60

92.70

92.80

92.90

93.00

93.10

0 10 20 30 40 0 2 4 6

92.225

92.325

92.425

92.525

92.625

92.725

92.825

92.925

93.025

93.125

92.20

92.30

92.40

92.50

92.60

92.70

92.80

92.90

93.00

93.10

0 2 4 6 8 10 12

Mean Standard Deviation

Flakes


Xlf

92

(Figure 17 and 27). It was collected to supplement the samples collected from Column A

that date to Early Paleoindian and older than Clovis times.

Texture Analysis. Between 92.20-92.45 m the sediment becomes coarser up the

profile. The mean starts at 8.5 phi and decreases to 4.9 phi. The percentage of gravel and

sand increases, peaking at 28% and 23% respectively, while the percentage of silt and

clay decreases to 20 and 33% respectively.

From 92.45m to 92.70 m, the texture remains fairly homogenous around a mean

of 5 phi. The texture begins to fine upwards after 92.75 m. The fluctuations of the

texture between 92.925 m and 93.025 m are, for the most part, tied to the previously

mentioned problem of separating calcium carbonate nodules from the gravels. At 92.975

m, however, there is a decrease in the percentage of sand from 10.5% to 7.2%, silt

increases from 24% to 47%, and clay increases from 35% to 46%.

Calcium Carbonate. The percentage of calcium carbonate increases from 10.2%

at the base of the profile to 36.4% by 92.35 m. The percentage of carbonate remains in

the 30-40% range from 92.35 to 92.75 m. After the percentage of carbonate begins to

drop from 30% at 92.75 m, there is a steady decline until the percentage reaches 6% at

93.15 m.

Organic Carbon and Organic Matter. The general trend is for organic content to

increase up the profile. At the base of the profile the percentage of organic carbon is

0.28% and organic matter is 3.07% while organic carbon is 0.81% and organic matter is

3.6% at the top of Column C. Between 92.85-93.10 m the percentage of organic matter

and organic carbon increases a few extra percentage points and is higher than the general

trend of the curve.

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93

93

93


increase up the profile from 7.2 at the base to 34 10-8

m3kg

-1 at the top. There was a shift

and an increase in the low frequency reading at 92.85 m.

Field Observations. The cracks and calcium carbonate nodules along this

section of the north wall are leaning slightly to the north east. It could be the result of

soil creep.

Column D

These samples were taken from sediment collected within a large pile of

pedestalled cobbles (Figure 18 and 28). The majority of the cobbles here (2-300 mm) are

larger than the cobbles (2-100 mm) seen at this elevation in the rest of the excavation

block. Saprolite (degraded limestone) is prevalent here.

Texture Analysis. The texture becomes increasingly fine from the base of the

profile at 92.09 m to 92.19 m. The percentage of gravel drops from 20% at 92.09 m to 4-

6% between 92.14-92.24 m. After 92.19 m, the texture starts to become coarser again.

From 92.29 m to the top of the profile at 92.44 m, the texture remains fairly consistent

with a mean around 5.8 phi.

While the texture is not as fine or well-sorted as the floodplain deposits seen in

the upper elevations of Columns A and B, these samples are better sorted than the rest of

the deposits from low elevations within the excavation block.

Calcium Carbonate. The percentage of calcium carbonate increases from 19% at

the base of the profile to 42% by 92.32 m. The percentage of carbonate drops to 33% at

the top of the profile at 92.42 m.

94


& Cultural Horizons




e. Calcium Carbonate (%) f. Organic Carbon & Organic Matter

(%)

g. Magnetic Susceptibility (10-8

m3kg

-1)

h. Flakes (grams)

Figure 28. Analysis results for Column D are presented in Figures 28a-h. Numerical data is presented in Appendix B.

92.09

92.14

92.19

92.24

92.29

92.34

92.39

92.44

0 1 2 3 4 5

Walkley-Black LOI

92.09

92.14

92.19

92.24

92.29

92.34

92.39

92.44

0 10 20 0 1 2 3 4 5

92.1225

92.215

92.315

92.415

Flakes

92.09

92.14

92.19

92.24

92.29

92.34

92.39

92.44

0 2 4 6 8 10 12

Mean Standard Deviation

92.09

92.14

92.19

92.24

92.29

92.34

92.39

92.44

0 10 20 30 40 50

Chittick LOI Xlf

95

Organic Carbon and Organic Matter. The organic carbon and organic matter

percentages remain nearly consistent throughout Column D. Organic carbon stays

between 0.51 and 0.59%, while organic matter hovers between 2.6 and 3%.


remain nearly consistent throughout Column D, ranging between 5 to 8 10-8

m3kg

-1.

Field Observations. Redox features and saprolite were noted in the field

descriptions. Gleying, which results from prolonged soil saturation and occurs under

reducing conditions (Schaetzl and Anderson 2005:759), was observed.

Artifacts. There are only a few, very small flakes; nonetheless, flakes were

recovered from these bulk sediment samples.

96

6. DISCUSSION

Now that the results of the analyses have been laid out, a holistic approach

comparing and contrasting the collected data will be employed to discuss the

sedimentary, pedogenic, and post-depositional processes that may have affected Area 15

at the Gault site. Additionally, a discussion of how the results of this study compare to

other studies conducted within Buttermilk Creek valley and within Central Texas will be

provided.

Area 15

Sedimentary Processes. Bulk sediment samples in Columns A and C were used

to classify and describe Units 1 and 2 (see Figures 23-24 and 27; Appendix A and B).

Units 1 and 2 are clay loams. Field observations documented pebbles and cobbles.

There is a sharp increase in the percentage of calcium carbonate in Unit 2 compared to

Unit 1. It should be noted that bedrock had not been reached at the time the bulk

sediment samples were collected. Therefore, additional stratigraphic units may underlie

Unit 1, although the sediment remains gravelly until bedrock.

The high percentage of sand and gravel between the bottom of the profile and

92.55 m in Column A suggests sedimentary Unit 1 and possibly Unit 2 are laterally

accreted channel deposits (Waters 1992:132). A seismic reflection line (Hildebrand et al.

2007) which ran near Area 15’s location, revealed a paleochannel that cut into the

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97

bedrock of the valley and was covered by gravels and clay. Hildebrand et al. observed

that the topographic contours of the valley suggest the course of Buttermilk Creek or one

of its tributaries once ran north of the creek’s current position.

The textural changes and sedimentary units in Column C are similar to the pattern

observed in Column A. However, unlike the coarse deposits beneath 92.50 m in Column

A, the texture for deposits beneath 92.45 m in Column C is fine. The coarser deposits in

Column A likely represents higher energy events within the stream while the finer

deposits in Column C are from a lower energy event.

While additional OSL dates from Area 15 are being processed at the time of this

writing, a more refined OSL chronology is needed to date the depositional sequence of

Units 1 through 4. An OSL date at the top of Unit 1 indicates that Unit 1 was deposited

around ≥13,900 calendar years B.P. While Units 1 and 2 were being deposited, the

environment in Central Texas was experiencing increased aridity and seasonality of

precipitation as compared to the cooler and wetter conditions during the Last Glacial

Maximum (Blum et al. 1994; Toomey et al. 1993). Arboreal communities were present

at Boriack Bog between 18,000-14,700 cal. years B.P. (Bousman and Oksanen 2012;

Figure 29). Once the Last Glacial Maximum ended at 14,640 cal. years B.P. (Bousman

and Vierra 2012; Figure 29), there was a shift to warmer conditions and an increase in

grassland plant communities. Figure 29 presents the stratigraphic units from Area 15 as

compared to pollen data from Boriack Bog as well as the NGRIP and GRIP ice core

record. By 15,100 cal. years B.P. the summer temperatures were within 2-3oC of the

modern values (Toomey et al. 1993).

In Units 3 and 4, between 92.50-92.95 m in Column A, there is a decrease in the

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98

Figure 29. The pollen data from Boriack Bog and the NGRIP and GRIP ice core

record (Bousman and Oksanen 2012) as compared to stratigraphic units at Area 15.

percentage of sand and an increase in silt and clay. These units have a finer texture than

the sedimentary units below or above them. Units 3 and 4, as classified and described in

Columns A and C (see Figures 23-24 and 27; Appendix A and B), are clays.

0

10

20

30

40

50

60

70

80

90

4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Pe

rce

nt

of

Arb

ore

al

Po

lle

n

Cal kyrs BP

Arboreal Pollen Poaceae Pollen

GS-2a GS-1

8.2 9.3 PB YD

GI-

1e

GI-

1c

2 & 1 9 & 8 7 6 5

4

&

3

date for bottom

of Unit 1 is

unknown

STRATIGRAPHIC

UNITS

stable land

surface or

erosional?

erosional

event?

99

99

99

99

The decrease in the coarseness of the sediments above 92.50 m suggests a switch to

vertically accreted floodplain deposits. During overbank flooding, fine-grained,

suspended load sediments are carried out of the channel and deposited on the floodplain

(Waters 1992:134). The switch from laterally accreted channel deposits to overbank

floodplain deposits occurred prior to the arrival of peopled during the Clovis period.

Clovis artifacts begin to appear at 92.65 m and are associated with Units 3 and 4. The

decrease in the weight and number of flakes between 92.50-92.65 m (Figure 25), suggests

a sterile zone at the base of Unit 3and a break in human occupation.

Following the deposition of Units 1 and 2 prior to ~13,500 calendar years B.P.,

the climate continued to become warmer and drier during the Clovis period (Nordt et al.

1994; Toomey et al. 1993). Arboreal pollen communities were identified at this time in

Central Texas (Bousman and Oksanen 2012; Nickels and Mauldin 2001) and dominated

the landscape during the Clovis period.

Magnetic susceptibility can be used to detect erosional surfaces. There is a slight

spike in the low frequency readings between Units 3 and 4 in both Columns A and C,

suggesting a possible erosional event. The slight increase, however, could have been

caused by another factor, such as a cultural activity that occurred during Clovis times.

The gap in age between Units 4 and 5 (Figure 29) may represent a stable land

surface or an erosional surface. The lack of more refined OSL chronology for Unit 4 and

the sparse nature of the Folsom component at Gault makes this hard to determine. The

age for the upper boundary age of Unit 4 is defined by the Clovis artifacts it contains.

The base of Unit 5 is defined by an OSL date to 10,410 calendar years B.P. and a Wilson

point, which dates between 11,200-10,400 cal. years B.P. (Bousman and Oksanen 2012).

100

100

100

100

The Wilson point is the youngest diagnostic artifact contained in the Late Paleoindian

deposits at Gault and defines Unit 5 as a Late Paleoindian component. That Unit 4

contains a paleosol, which is indicative of a stable land surface, and that a Folsom point

was recovered from an earth oven in Area 15, both suggest that the age-break represents a

stable land surface rather than an erosional surface.

Continuing up the profile, several sequences of floodplain deposits were

identified (Units 5 through 10). These sediments were deposited between 13,000 cal.

years B.P. and the modern day, a period which is characterized by a general increase in

temperature and a decrease in moisture (Bousman 1998; Meier et al. 2013; Nordt et al.

1994; Nordt et al. 2002; Toomey et al. 1993). Units 5, 6, 7 and 8 generally have fining

upward sequences. While the mean hovers just below 9 phi for these units, there are jogs

in the mean and sorting. The texture for each unit is clay.

The fluctuations in silt and clay in Unit 6 suggests episodic flooding occurred

between 10,000 and 6650 calendar years ago, as the percentage of grass pollen steady

increased relative to arboreal pollen (Bousman and Oksanen 2012). This contrasts with

the Late Paleoindian period following Clovis (between 10,500 and 10,000 calendar years

ago), as deposition in Unit 5 was consistently calm and low magnitude. The percentage

of arboreal pollen exceeded 50% during this interval (Bousman and Oksanen 2012). The

sediment fluctuations in Units 1, 2, 3, and 4 suggest these sediments may have been

deposited by a flashy, episodic hydrological regime as well. The episodic flooding

events may have been triggered by the fluctuations in climate that were occurring after

the end of the Last Glacial Maximum.

The deposits in Units 1 through 4 and Unit 6 may indicate there were two periods

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101

Table 4. Summary of the changes in the hydrologic regime at Area 15.

Units Dates Hydrologic Regime

1-4 ≥ 10,500 calendar years ago Flashy

5 10,500-10,000 calendar years ago Low Magnitude

6 10,000-6650 calendar years ago Flashy

7-10 6650 calendar years ago to present Low Magnitude

of extreme conditions with large magnitude precipitation events bounded by much less

flashy precipitation. See Table 4 for summary of this discussion. Gibson (1997)

describes the Lim and Eden Alluvium as being the result of a flashy hydrologic regime.

These deposits, however, date between 5700 and 2300 cal. years B.P. and are younger

than the deposits in Area 15 that are indicative of a flashy hydrologic regime.

While magnetic susceptibility results do not suggest an erosional surface between

Units 6 and 7, the significant break in the ages between these units is probably the result

of an erosional surface. The top of Unit 6 is defined by an OSL date to 9460 calendar

years B.P., and Late Paleoindian diagnostic materials in Unit 6 corroborate this date. The

base of Unit 7 is OSL dated to 6650 calendar years B.P. The brief dip in Poaceae pollen,

increase in arboreal pollen, and the return to cooler temperatures at approximately 6800

cal. years B.P. may have triggered an erosional event (Figure 29).

The gravels in Units 7, 8, 9 and 10 were likely deposited through colluvial

processes or were introduced culturally. Area 15 is located near where the floodplain

intersects with a colluvial toe slope (Figure 9). The thick deposits of the Archaic midden

probably prevented deposition of gravels through overbank flooding. Bulk sediment

samples in Columns A and C were used to classify and describe Unit 5 (see Figures 23-

24 and 27; Appendix A and B) while samples from Units 6, 7, 8, and 9 came from

Column A (see Figures 23-24; Appendix A and B).

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The sediment in Units 7 through 10 has been deposited since ~6700 calendar

years B.P. The climate was briefly mesic between 6800 to 6000 cal. years B.P.

(Bousman and Oksanen 2012; Nickels and Mauldin 2001). Between 5700 cal. years B.P.

and 750 cal. years ago the climate returned to warm and dry conditions. For the last 750

years, however, Central Texas has been mesic (Nickels and Mauldin 2001). Grassland

communities, which were dominant across Central Texas until 1800 cal. years B.P.

(Bousman 1998; Bousman and Oksanen 2012), covered the landscape during the

deposition of Units 7 and 8 and possibly Units 9 and 10.

A small shift in the low frequency readings at 93.95 m, between Units 7 and 8,

could be representative of a truncation event. There is not a significant break in the OSL

chronology, however. The increase in the low frequency readings could have been

caused by a hearth feature. Anthropogenic fires can also result in increased levels of

magnetic susceptibility (Bartington Instruments 2013) and burned rocks are present

between 93.80 and 93.95 m. If this indeed represents an erosional surface, the erosional

event would have occurred during a brief climatic change between 6800 and 6000 cal.

years B.P. This timeframe is described as a brief return to mesic conditions (Bousman

and Oksanen 2012; Nickels and Mauldin 2001) that was followed by a sharp increase to

warm conditions between 6-5000 cal. years B.P. as grass pollen percentages reached as

high as 80%. Nordt et al. (1994), however, describes the period between 6800 and 5700

cal. years B.P. as a warming trend (Nordt et al 1994).

The breaks between stratigraphic units in Column B are the most ambiguous of

the three columns. A truncation event between Units 9 and 10 is suggested at 94.625 m

by the shift in the low frequency magnetic susceptibility readings and is probably

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representative of the plow-zone. The shift, however, could have been the result of the

formation of an A-horizon on top of the already elevated readings caused by a hearth

feature. Burned rocks are present between 94.40 and 94.60 m.

There are three sedimentary units in Column D, which cannot be correlated with

the stratigraphic units seen in Columns A, B, or C based on the results for the bulk

sediment samples collected. The bottom unit is the coarsest. A truncation event is

suggested at 92.175 m by the shift in the low frequency magnetic susceptibility readings,

the texture, and the calcium carbonate percentage. Above the erosional surface, the

sediment becomes finer. Overall, the sediment that collected within the pile of cobble to

boulder sized rocks is fine grained.

Pedogenic Processes. As soil develops, materials are moved through the profile.

Surface horizons are rich in organic material but leached in weatherable minerals.

Paleosols (which represent what was once a stable surface) are marked by increased

organic matter content, decreased CaCO3 content (Schaetzl and Anderson 2010), and

increased levels of magnetic susceptibility (Crowther 2003). Anthrosols, which are soils

modified by human activities, would be indicated by increased organic matter content

and increased levels of magnetic susceptibility (Weston 2002; Holliday 2004).

To highlight how Columns A, B, and C are linked, the relationship between the

cultural horizons, soil horizons, and stratigraphic units in these columns are shown in

Table 5. The approximate boundaries of the stratigraphic units across the excavation

block are presented in Figure 30. A profile depicting all stratigraphic units and

pedogenic horizons with calcium carbonate, organic carbon, and magnetic susceptibility

data to highlight the paleosols are portrayed in Figure 31.

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The oldest of the paleosols, between 92.80-92.95 m in Column A and 92.90-93.05

m in Column C, is suggested by the increase in the percentage of organic matter,

deceased levels of calcium carbonate, and elevated low frequency magnetic susceptibility

readings at these elevations (Figures 23-24, 27, and 30). In Column C, the increase in the

low frequency readings at 92.825 m could be representative of a truncation event but is

likely results from the presence of a paleosol. This paleosol stratigraphically underlies an

OSL date of 10,410 ± 350 years BP and is associated with Clovis-aged artifacts. The

presence of a paleosol suggests the landscape was stable toward the end of the Clovis

period following the possible erosional event between Units 3 and 4.

A weakly expressed paleosol or anthrosol, which was not observed in the field

descriptions, might be present between 93.60-93.80 m in Column A. There is a sharp

drop to 1.2% calcium carbonate, and a shift in the low frequency magnetic susceptibility

readings at 93.775 m, yet there is little change in the percentage of organic matter

(Figures 23-24 and 30).

Another paleosol or anthrosol is present in the Archaic midden between 94.00-

94.20 m (Figures 23-24 and 30). The Archaic midden itself represents intense human

activity (Collins 2002) and contains numerous earth oven features. Earth ovens introduce

organic matter. Additionally, fires result in increased magnetic susceptibility. If this

represents a paleosol, like the Clovis-aged paleosol, it represents a period of stability. An

OSL date collected from the middle of the paleosol or anthrosol dates to 5820 ±210

calendar years BP. The association of a possible event around 6000 calendar years B.P.

and the presence of a paleosol dating to either the brief return to mesic conditions (by

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Table 5. The relationships between the cultural horizons, soil horizons, and stratigraphic units in Columns A, B, and C. The

three stratigraphic units in Column D cannot be correlated to Columns A through C based on the results for the bulk

sediment samples collected.

Cultural Horizons Column A Column B Column C

Horizon Unit Elev. (m) Horizon Unit Elev. (m) Horizon Unit Elev. (m)

Archaic /

Late-Prehistoric

Ap

Disturbed by

looters pit and

plow zone

94.75-

surface A 10

94.65-

surface

Archaic Bss

Disturbed by

looters pit and

plow zone

94.45 94.75 Bss 9 base-94.65

Bss 9 94.20-94.45

Ab 8 94.00-94.20

Bkss1

7 93.55-94.00

Late Paleoindian 6 93.20-93.55

5 92.95-93.20 Bkss1 5 93.05-top

Clovis Abss 4 92.80-92.95 Abss 4 92.89-93.05

Bkss2 3 92.50-92.80 Bkss2 3 92.72-92.89

Pre-Clovis Bk

2 92.35-92.50 Bk

2 92.45-92.72

1 Base-92.35 1 Base - 92.45

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Figure 30: Approximate boundaries of the stratigraphic units across the excavations block.

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Xlf

CaCO3 nodules not removed from gravel

fraction

a. Stratigraphy and Soil Horizons

b. Calcium Carbonate (%)

c. Organic Carbon (%) d. Magnetic Susceptibility (10-8m3kg-1)

Figure 31. Profile that includes all stratigraphic units and pedogenic horizons and highlights data from Column A and B.

92.1092.2092.3092.4092.5092.6092.7092.8092.9093.0093.1093.2093.3093.4093.5093.6093.7093.8093.9094.0094.1094.2094.30

0 10 20 30 40 50

Chittick

92.1092.2092.3092.4092.5092.6092.7092.8092.9093.0093.1093.2093.3093.4093.5093.6093.7093.8093.9094.0094.1094.2094.30

0 1 2 3

Walkley-Black

92.1092.2092.3092.4092.5092.6092.7092.8092.9093.0093.1093.2093.3093.4093.5093.6093.7093.8093.9094.0094.1094.2094.30

0 40 80 120 160 200


94.4094.5094.6094.7094.8094.90

94.4094.5094.6094.7094.8094.90

94.4094.5094.6094.7094.8094.90

Column B data

Column A data

Column B data

Column A data

Column B data

Column A data

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Toomey et al. 1993) or a warming trend (by Nordt et al 1994) between 6800 and 5700

cal. years B.P., suggests that the change in climate triggered an erosional event and that

as the climate stabilized the landscape surface became stable.

A modern A-horizon is suggested by the high levels of organic matter content and

low frequency magnetic susceptibility readings at the top of the profile (Figures 26 and

30).

Redox depletions with a chroma of ≤2 are present in Units 1 and 2 in column A

and throughout Column D. Redoximorphic features with a chroma of <2 are indicative

of aquatic conditions (Schoeneberger et al. 2002:2-14). In a reduced environment, the

soil undergoes a chemical reaction that reduces and mobilizes iron and magnesium along

macrovoids and ped faces. Therefore, the presence of low chroma mottles in the levels

directly above the water table at the Gault site, suggests these soil packages were altered

by fluctuations in the water table.

The general trend of the calcium carbonate percentage is to increase with depth

until 92.30 m in Column A and 92.35 m in Column C, where the percentage sharply

decreases. This roughly correlates with Unit 1. The decrease in the percentage of

calcium carbonate could be indicative of the elevation and behavior of the water table.

Secondary carbonates accumulate where there is a source of calcium and where there is

inadequate water to translocate it from the profile (Schaetzl and Anderson 2005:402).

Post-Depositional Processes. Bioturbation is an active force at the Gault site, as it

is at all archaeological sites. Fine to medium roots were observed above 93.20 m and

root casts have been documented in most sedimentary units. Krotovina, probably from

earthworms and ants, were observed in Units 7, 8, 9, and 10.

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Johnson (1989) describes stone lines created by burrowing pocket gophers. These

subsurface zones of large stones are greater than 6 cm deep. A seismic reflection study

(Hildebrand et al. 2007) conducted at Gault, however, shows that gravels directly

overlying the bedrock are spread across a wide area. Limestone gravels overlying

bedrock are also present in other areas of the Gault site (Luchsinger 2002) and the valley

(Gibson 1997). Additionally, gravels directly overlying bedrock are seen at other

localities in Central Texas (Nordt 1992, 1993). Therefore, it is unlikely that the gravels

seen at depth in Area 15 are the result of burrowing gophers.

The soil at the Gault site is classified as a Vertisol. As there are several sources of

potential disturbance of the archaeological record by Vertisols, pedoturbation is an

important discussion point. Cracks, some as wide as ~2 cm, were observed in the soil.

Cracks are a common feature of Vertisols (Graham 2006) and introduce the possibility

for artifacts to fall to a lower elevation. The widest cracks were at the surface, with the

width of the cracks decreasing with depth. It should be noted that when a crack formed

in the Gault soils, flakes and other cultural materials were often “gripped” by the clay and

held in place by the walls of the crack.

The distinctive notching flakes from Andice points are mostly confined to a 10

cm zone in the Archaic midden while intact Andice points are found across a 45 cm zone

(Sergio Ayala, personal communication). If artifacts were falling down through the

cracks, the smaller notching flakes would be more dispersed than the larger diagnostic

points. Microdebitage (<0.625 cm) at the neighboring Friedkin site, however, is moving

downward through the cracks while the larger artifacts remain in place (Keene 2009).

Another potential source of pedoturbation is from the self-mulching of Vertisols,

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where cobbles and other material are removed from depth and translocated to the surface

(Wilding and Tessier 1988). Artifacts may be carried to and deposited on the surface

through the Vertisol’s self-mulching process (Graham 2006; Schaetzl and Anderson

2005; Wilding and Tessier 1988). The presence of the cobble zone at the base of the

profile, suggests that the self-mulching mechanism is not very active in the Gault

Vertisol. The majority of the cobble-sized rocks at higher elevations was introduced

culturally and is associated with hearths and earth ovens. Additionally, the percentage of

calcium carbonate steadily increases with depth from the surface to 92.35 m. The amount

of calcium carbonate coating the pebbles and cobbles at the base of the profile is

distinctive. If the self-mulching mechanism were moving these cobbles upward through

the profile, there would be a heavy coating of calcium carbonate on the gravels and

cobbles throughout the profile instead of the steady increase with depth that is observed

in Area 15.

Overall, while there are potential sources for bioturbation, pedoturbation, and so

forth, the diagnostic artifacts and OSL dates from Area 15 tend to agree. Unit 1 contains

artifacts technologically distinct from Clovis lithic material. The top of Unit 1 was dated

by multiple aliquot OSL to 13,870±440 calendar years BP. The decrease in the number

and weight of flakes between pre-Clovis and Clovis artifact assemblages (Figure 25),

suggests the assemblages are separated by a break in occupation. Clovis dates to between

12,900-13,500 calendar years BP. Units 5 and 6, which contain Late Paleoindian

diagnostic artifacts, including Angostura, Wilson, Dalton and St. Mary’s Hall, are OSL

dated to 9460±300-10,410±350 calendar years BP. In the Archaic, the diagnostic

artifacts do not align as well as the pre-Clovis, Clovis, and Late Paleoindian artifacts.

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This was likely the result of cultural processes, such as the building of hearth features and

earth ovens and not the result of pedoturbation or bioturbation.

Buttermilk Creek Valley

Sedimentary and Pedogenic Processes. Gibson (1997:76-79) outlines a

chronology of deposition and erosion for the Buttermilk Creek drainage system that

closely follows Nordt’s (1992, 1993) chronology at Fort Hood (see Table 6). Gibson’s

chronology aligns with results of this study at a few points. Gibson argues that the gravel

rich alluvium was deposited just prior to 18,000 cal. years BP. Gibson also states that the

land surfaces in the valley were stable between 18 to 14,000 cal. years B.P. However,

results from Area 15 suggest sedimentation continued and that Unit 1 was deposited

during this time-frame.

Gibson (1997) states that deposition began again around 14,000 cal. years B.P and

continued until 9,000 cal. years B.P., at which point, the valley became stable. The

depositional period between 11 and 14,000 cal. years BP could be represented by Units 2,

3 and 4. While Gibson describes the Brown Paleosol, Nordt (1992, 1993) describes the

Royalty Paleosol, and Luchsinger names a paleosol within Area 8 as the Royalty

Paleosol, there is no evidence of a paleosol forming at Area 15 around 8000 cal. years

ago. Sedimentation began again from 9 to 5700 cal. years B.P. and could have produced

Units 7 and 8. Gibson suggests the land surface was stable 5700 years ago, which aligns

with the Archaic-aged paleosol described above.

There are similarities in the stratigraphic units at Area 8 and 15 (Table 7). The

Clovis and Late Paleoindian components at both areas are each confined to two units.

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Table 6. Comparison between the stratigraphic units at Fort Hood (Nordt 1992, 1993), Buttermilk Creek (Gibson 1997), and

Area 15.

Fort Hood Buttermilk Creek Area 15 Stratigraphic

Unit

Age Stratigraphic

Unit

Age Stratigraphic

Unit

Cultural

Affiliation

Notes

Ford

Alluvium

present - 600

cal. years B.P. Adams

Alluvium

present - 100

cal. years B.P. Unit 10 Late-Prehistoric?

and Archaic Modern

A-horizon

West Range

Alluvium

600 - 4800

cal. years B.P. Eden

Alluvium

100 - 900

cal. years B.P. Unit 9 Archaic Contains snail

hash

Lim

Alluvium

2300 - 5700 cal.

years B.P. Unit 8 Contains a

paleosol

Fort Hood

Alluvium

5500 - 9000

cal. years B.P. Solona

Alluvium

5700 - 9000

cal. years B. P. Unit 7

Unit 6 Late

Paleoindian

Georgetown

Alluvium

(contains the

Royalty

Paleosol)

9000 - 12,700

cal. years B.P. Roden

Alluvium

(contains the

Brown

Paleosol)

9000 - 11,000 or

14,000 cal. years

B.P.

Unit 4 Clovis Clovis Soil

Unit 3

Jackson

Alluvium

~18,000 cal.

years B.P. Lankford

Alluvium

>18,000 cal.

years B.P. (date

based on region

pattern)

Unit 2 Pre-Clovis Limestone

Gravel Unit 1

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Table 7. Comparison between the stratigraphy in Area 8 and Area 15.

Area 8 Area 15 Stratigraphic

Unit

Cultural

Affiliation

Notes Stratigraphic

Unit

Cultural

Affiliation

Notes

Unit 7b Archaic Unit 10 Late-

Prehistoric?

and Archaic

Modern

A-horizon

Unit 6b Archaic Shell hash

midden Unit 9 Archaic Contains

snail hash

Unit 5b

Archaic Unit 8 Archaic Contains a

paleosol

Unit 7 Archaic

Unit 4c Late

Paleoindian

“Royalty

Paleosol” Unit 6 Late

Paleoindian

Unit 4b Late

Paleoindian

Unit 5 Late

Paleoindian

Unit 3b Clovis Clovis Soil Unit 4 Clovis Clovis Soil

Unit 3a Clovis Clovis

Pond Clay Unit 3 Clovis

Unit 2 None Limestone

gravel Unit 2 Pre-Clovis Limestone

gravel Unit 1 Unit 1

The upper Clovis-aged units at Areas 8 and 15 contain a Clovis-aged paleosol. Although,

there are more stratigraphic units dating to the Archaic at Area 15 than there are at Area

8. Also, what is described as the Royalty Paleosol at Area 8 is not present at Area 15,

and there is no evidence of an Archaic-aged paleosol or anthrosol at Area 8. Both Areas

8 and 15 have a snail hash layer in the Archaic deposits.

Post-Deposition Processes. Other studies conducted at the Gault site and

neighboring Friedkin site suggest that while post-depositional processes do affect the

cultural material and stratigraphic horizons, that effect is minimal. Luchsinger and

Alexander conducted studies in Area 8. Luchsinger concluded that the formation of

calcium carbonate nodules is primarily pedogenic. Therefore, the increase in calcium

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carbonate with depth reflects the increasing age of the deposits in both Area 8 and 15.

Additionally, as in Area 15, the redox features in Area 8 were strongest at the base of the

profile near the water table.

Luchsinger observed in her micromorphological analysis (2002:104-107) that

micro-bioturbation blurred the stratigraphic units and occupational surfaces at Area 8.

The boundaries between the stratigraphic units in Area 15, as observed through field

observations and analysis results, are gradual. The deposits in Area 15 are thick. While

fine, delicate stratigraphy might be easily destroyed by micro-bioturbation, the damage to

the stratigraphy within Area 15 is limited by its thickness. For example, even if micro-

bioturbation is active, the relatively sterile layer between the Clovis and pre-Clovis

material acts as a buffer.

Furthermore, Alexander’s (2008) artifact orientation analysis and re-fit study of

Clovis artifacts suggested there was only minimal movement of the artifacts due to

secondary displacement by natural agents. The random orientation of the artifacts shows

no evidence of sorting by natural agents, such as stream action, pedoturbation, or

bioturbation. Alexander’s refit study found that 67% of refit artifacts moved less than 5

cm compared to the other artifacts in their refit groups.

In Buttermilk Creek, the quartz dust and iron-staining of calcium carbonates, as

described by Luchsinger (2002), were used by Luchsinger as an environmental proxy.

Consequently, she suggested the Early and Late Paleoindian periods were moister than

the entire Archaic period. The higher concentration of quartz grains during the Clovis

period than the Late Paleoindian suggests that the Clovis era was subject to periodic

droughts.

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Central Texas

Nordt (1992) attributes the episodes of channel degradation and aggredation to the

dual mechanisms of Late Quaternary climatic shifts and the depletion of upland soils.

This study identifies ten sedimentary units, three possible erosional surfaces, and two

paleosols in Columns A through C. A more refined chronology of OSL dates is needed

to understand the temporal relationship between the deposition of these units and those

described in other Central Texas studies, such as Nordt’s (1992, 1993) work at Fort

Hood. As there is only one OSL date for Units 1 through 4, these units cannot be related

to the Fort Hood stratigraphy. Units 5 and 6 (~11-9000 cal. years BP) are approximately

contemporaneous with the Georgetown Alluvium (~12,700-9000 cal. years BP) (Nordt

1992). Units 7 and 8 (~6700-5800 cal. years BP) were deposited within the depositional

period for the Fort Hood Alluvium (9-5500 cal. years BP).

Nordt (1992) describes erosional discontinuities at 8800 cal. years BP, 5500-4800

cal. years BP, and 500 cal. years BP. In Area 15, there is a possible erosional surface

between 7-9000 years BP where there is a break in OSL dates and another possible

truncation event at ~6000 years ago. Nordt (1992, 1993) describes the Royalty Paleosol,

which would have formed approximately 8800-10,200 cal. years BP. There is, however,

no evidence of a paleosol forming at Area 15 during this period.

The modern soils overlying the Lower Cretaceous bedrock of the Edwards

Plateau are thin and gravelly across Central Texas. The deflation of soils on the Edwards

Plateau -- which was probably triggered by increased aridity, temperature, and

seasonality of precipitation (Blum et al. 1994; Toomey et al. 1993) -- either began 21,000

years ago (Cooke 2005) or during the Early Holocene (Nordt 1992). Regardless of the

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timing for this deflation event in Central Texas, the deep, stratified deposits present at

Gault clearly escaped this scouring event.

Where to Look for “Old Dirt”

Changes in the landscape since the time of occupation can create problems for site

visibility (Waters 1992:100). A site positioned at depth within a floodplain cannot be

detected through traditional survey methods. A growing number of geoarchaeologists are

strategically looking for archaeological sites where “old dirt” is known to be located [e.g.

C. Reid Ferring (2001) at the Aubrey site in northern Texas; Bousman and Skinner

(2007) along the North Sulphur River valley in Northeastern Texas; Darrin L. Lowery, et

al. (2010) on the Delmarva Peninsula; and Loren Davis and others along the southern

Oregon coast (see Davis et al. 2004, Hall et al. 2002, and Punke and Davis 2006)].

Considering the geomorphic history of Central Texas, deeply stratified deposits

are rather rare. A limited number of stratified Paleoindian sites, containing material from

multiple occupational phases, have been documented in Central Texas thus far. Besides

the Gault site, these include Wilson-Leonard (Bousman et al. 2002; Collins 1998c), Pavo

Real (Collins et al. 2003), and Rob Roy (Jackson 1939), all of which are associated with

fluvial deposits.

The Wilson-Leonard site is a deeply stratified, multicomponent prehistoric

archaeological site located in Williamson County about 5 km northeast of Cedar Park,

Texas. Cultural material spans every significant cultural period in Central Texas, from

the Paleoindian period to the Late Prehistoric Period. Like Gault, the site is located in the

ecotonal location between the savanna habitats of the Edwards Plateau and the tall grass

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prairie habitats of the Blackland Prairie on the interior coastal plain (Collins 1998a).

Prehistoric people living here, as at Gault, would have been able to take advantage of the

resources of the Edwards Plateau, the Balcones Canyonlands, and the coastal plain.

The Wilson-Leonard site lies within the Brushy Creek valley. Brushy Creek has

three thin and narrow fluvial terraces where Wilson-Leonard is located. More than 6 m

of fluvial valley fill and some colluvial additions have accumulated during the Holocene.

The valley has experienced only a few periods of erosion as well as protracted periods of

stability (Collins 1998b). The Early and Late Paleoindian archaeological record is better

stratified than the subsequent archaeological material due to a slowing rate of deposition

following the Late Paleoindian period (Collins 1998a). In general, the depositional

environment for the sediments at Wilson-Leonard changed with time from a high-energy

channel with a low-energy overbank system to overbank deposition with some channel

sediments and an increasing input from colluvium. Three moderately developed soils

and one weakly developed soil are present at the site.

Wilson-Leonard is situated on the outside of a moderately large bend in Brushy

Creek. Given the geomorphological understanding of stream systems, one would expect

this location to be dominated by erosional processes. While erosion was dominant at the

end of the Holocene and resulted in the scouring of the bedrock, the channel shifted to the

middle of the valley as a result of a probable decrease in energy flow. At this location

depositional processes dominated over erosional events (Collins 1998b; Holliday and

Goldberg 1998). The unexpected position of the deeply-stratified Wilson-Leonard site in

a location that is expected to experience erosion by the stream suggests that surveying

assumptions in addition to the already deflated landscape across Central Texas contribute

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to the difficulty in finding “old-dirt.”

Possible Directions of Future Research

Photo-sieving. Determining the texture proved problematic where calcium

carbonate was particularly prevalent. An analysis to determine the percentage of gravel

with micromorphological thin sections, a process called photo-sieving, would help to

resolve this issue and provide a better understanding of the variations in texture in the

lower elevations.

Size-Sorting. More work on post-depositional processes, namely pedoturbation,

should be conducted in the future. While it is clear that pedoturbation is occurring and

initial observations suggest it is only minimally affecting the cultural material at the

Gault site, it still remains unclear as to what degree it is affecting the artifacts. As

discussed in detail in Chapter 3, artifacts may be preferentially size-sorted by burrowing

animals (Balek 2002) or by falling down the cracks created by Vertisols (Graham 2006;

Schaetzl and Anderson 2005). Therefore, a study examining the size sorting of artifacts

could be conducted.

OSL dating. Most importantly, single-grain OSL dates need to be conducted to

assess turbation at the Gault site. In single- and multiple-aliquot dating, multiple grains

are measured at the same time with the luminescence signal being averaged. The

variability in the luminescence signal between grains within the sample will be obscured

(Duller 2008).

OSL measurements, particularly single-grain OSL measurements, can be used to

assess post-depositional disturbance. Disturbed sediments typically have a highly

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skewed multi-modal paleodose (De) distribution with higher overdispersion (OD) values

and zero dose grains at depth. Additionally, single grain and single aliquot results may

be significantly different (Bateman et al. 2007).

The multiple aliquot OSL dates already collected from Area 12 and 15 (Table 3)

have a very low overdispersion in the equivalent dose distribution (ranging between 0-

12%). Preliminary results, therefore, suggest minimal turbation of the sediment.

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7. CONCLUSIONS

Understanding changes in flora, fauna, physical landscape, and climate not only

expands our understanding of the environment in which people lived but is related to the

environment in which artifacts formed by those people were deposited. Depositional,

erosional, and pedogenic conditions are linked with the physical landscape as well as the

climatic and vegetative patterns interacting with that landscape. Natural formation

processes, as defined by Schiffer (1987), include all environmental processes that affect

the archaeological record.

A geoarchaeological analysis was conducted on sediments from Area 15 at the

Gault site to reconstruct the natural formation processes that affected the excavation

block. Particle-size analysis, calcium carbonate percentage, organic matter content, and

magnetic susceptibility were utilized to explore sedimentary, pedogenic, and post-

depositional processes that have affected the sediment and cultural materials. The

ultimate goal of this study was to determine the depositional and post-depositional

integrity of the sediment and cultural material.

The conclusions which can be made from this study are as follows:

1. Results suggest Buttermilk Creek, or one of its tributaries, deposited stream cobbles

(Unit 1), abandoned its channel, and migrated across the valley floor. Once it

abandoned, a thin layer of coarse channel abandonment sediments was deposited

(Unit 2). The abandoned channel was then overlain by fine grained, vertically

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accreted floodplain deposits (Unit 3-10).

2. Units 1 and 2 contain cultural material that has been OSL dated to pre-Clovis times.

At the base of Unit 3, between 92.50-92.70 m, there is a decrease in the number of

artifacts, suggesting a break in occupation. Unit 3 (above 92.60) and Unit 4 contain

Clovis artifacts. Therefore, the pre-Clovis and Clovis artifacts are contained in

geologically distinct and thick strata that are separated by a cultural break in

occupation.

3. Magnetic susceptibility indicates the base of the plow zone may be at 94.65 m in

Column A. Additionally, magnetic susceptibility suggests there may be an erosional

surface in the Archaic midden (94.00 m), a possible erosional surface in the Clovis

deposits (92.80-92.90 m), and another in the pedestaled cobbles in Column D (92.14

m).

4. As the floodplain deposits accreted, they underwent diagenesis and in-soil formation.

Paleosols are buried soils and represent periods of stability. The association of a

paleosol and Clovis material suggests there was a period of landscape stability at this

time. Another paleosol or anthrosol, which dates to the Archaic period, is present

toward the top of the profile. The Archaic-aged sedimentary deposits were heavily

affected by the intensity of human occupation.

5. A modern A-horizon and plowzone are present at the top of the profile.

6. Units 1 and 2 have been introduced to a reduced environment by fluctuations in the

water table. Additionally, a decrease of calcium carbonate at the base of the profile

may be indicative of water movement through the profile.

7. The dates for the erosional surfaces and periods of stability as well as for textural

122

122

122

changes through the profile indicate that the sediments at Gault reflect aspects of the

history of environmental change in Central Texas as identified in various regional

paleoclimatic studies.

8. Ultimately, the results of this study support the preserved context of the Paleoindian

strata. The pre-Clovis archaeological material is contained in a different and clearly

distinguishable stratigraphic context than the Clovis material. These results, when

paired with archaeological materials from Area 15, not only increase the

understanding of the Paleoindian record at the Gault site but provide further evidence

supporting pre-Clovis occupation of North America.

123

APPENDIX A: GEOLOGIC PROFILES AND DESCRIPTIONS

124

Figures 1. One of the geologic profiles for where Column A samples were collected.

125


126


127


128

Figure 5. One of the geologic profiles for where Column A samples were collected.

129

Table 1. Profile descriptions for Column A.

Horizon Unit

Elev.

(m)

BS

S # TXT

Field

Color Structure Consistence

Calcium

Carbonate

Redoximorphic

Features Contents

Lower

Boundary

Ap

Disturbed by

looters pit and

plow zone

94.75-

surface

56-

57

Clay Dry:

10 YR 5/2

Moderate,

medium-

fine,

subangular

blocky

Firm Few hard

nodules,

Few shells, burned

rock, gravels,

flakes, krotovinia,

and ochre. Common

roots. Many cracks.

Gradual

smooth

Bss

Disturbed by

looters pit and

plow zone

94.45

94.75

50-

55

Clay Dry:

10 YR 3/1

Very dark

gray

Moderate,

medium

angular

blocky

Hard Few hard

nodules,

common

coatings,

Few shells, burned

rock, gravels,

flakes, krotovinia,

and ochre. Common

roots. Many cracks

Gradual,

wavy

Bss 9 94.20-

94.45

45-

49

Clay Dry:

10 YR 3/1

Very dark

gray

Moderate,

medium

angular

blocky

Hard Few hard

nodules,

common

coatings,

Few shells, burned

rock, gravels,

flakes, and ochre.

Common roots

Many cracks

Gradual,

wavy

Ab 8 94.00-

94.20

41-

44

Clay Dry:

10 YR 3/2

Very dark

grayish

brown

Moderate,

medium

angular

blocky

Slightly hard Common hard

nodules,

common

coatings,

Few, faint strong

brown (7.5 YR

5/6) mottles

Few gravels, shells,

burned rock, and

flakes. Common

cracks.

Clear,

wavy

Bkss1 7 93.55-

94.00

32-

40

Clay Dry:

10 YR 4/1

Dark grey

Strong,

medium

angular

blocky

Very hard Common

coatings,

common

nodules, few

filaments

Few, faint strong

brown (7.5 YR

5/6) mottles

Few burned rocks,

gravels, flakes, fine

roots, root casts,

ochre, and shell.

Common cracks.

Clear,

wavy

6 93.20-

93.55

25-

31

Clay Dry:

10 YR 4/1

Dark grey

to

10 YR 5/2

Grayish

Brown

Weak,

medium

angular

blocky

Hard Common hard

nodules and

coatings

Common, faint

brownish yellow

(10 YR 6/6)

mottles

Few fine roots, few

shells, few flakes,

few burned rocks,

common rounded

limestone and chert

gravels, common

cracks

Clear,

smooth

130

Table 1, continued. Profile descriptions for Column A.

5 92.95-

93.20

20-

24

Clay Dry:

10 YR4/2

Dark

greyish

brown

Weak,

medium

angular

blocky


nodules and

coatings

Common, faint

brownish yellow

(10 YR 6/6)

mottles

Few fine roots, root

casts, shells, and

flakes. Common

rounded limestone

and chert gravels.

Common cracks

Clear,

smooth

Abss 4 92.80-

92.95

16-

19

Clay Dry:

10 YR 5/2

Greyish

brown

Medium,

moderate

angular

blocky

Very hard Common hard

nodules and

coatings

Common,

distinct

yellowish brown

(10 YR 5/4)

mottles. Fe-Mg

nodules present.

Few flakes, root

casts, rounded

limestone and chert

gravels. Common

cracks

Clear,

smooth

Bkss2 3 92.80-

92.50

10-

15

Clay Dry:

10 YR 5/2

greyish

brown

Medium,

moderate

angular

blocky


nodules,

coatings, and

filaments.

Common,

distinct

yellowish brown

(10 YR 5/4)

mottles. Fe-Mg

nodules present.

Saprolite present.

Few gravels and

flakes.

Clear,

smooth

Bk 2 92.50-

92.35

7-9 Clay

Loam

Wet:

10 YR 5/6

Yellowish

brown

Medium,

weak

subangular

blocky

Plastic (wet) Common hard

nodules,

common

coatings,

common

filaments,

many soft

masses

Common (20%),

prominent gray

(10 YR 5/1),

dark gray (10

YR 4/1), and

yellow (10 YR

7/6) mottles

Saprolite present.

Few cracks and

angular to

subrounded

limestone and chert

gravels.

Gradual,

smooth

1 92.35-

base

1-6 Clay

Loam

Wet:

10 YR 5/6

Yellowish

brown

Medium,

weak

subangular

blocky

Plastic (wet) Few hard

nodules,

common

coatings,

common

filaments,

common soft

masses

Common (20%),

prominent gray

(10 YR 5/1),

dark gray (10

YR 4/1), and

yellow (10 YR

7/6) mottles

Saprolite present.

Few angular to

subrounded

limestone and chert

gravels and cobbles

(2-100 mm).

131

Figure 6. Geologic profile for where Column B samples were collected.

132

Table 2. Profile descriptions for Column B.

Horizon Unit

Elev.

(m)

BSS

# TXT

Field


Calcium

Carbonate

Redoximorphic

Features Contents

Lower

Boundary

A 10 94.65-

surface

58-

60;

66-

67

Clay Dry:

10 YR 5/2

Grayish

brown

Moderate,

medium-

fine,

subangular

blocky

Firm Few shells, burned

rock, gravels,

flakes, and ochre.

Many cracks

Gradual

smooth

Bss 9 base-

94.65

61-

65

Clay Dry:

10 YR 3/1

Very dark

gray

Moderate,

medium

angular

blocky

Hard Few hard

nodules,

Few shells, burned

rock, gravels,

flakes, and ochre.

Many cracks

Gradual,

wavy

133

Figure 7. Geologic profile for where Column C samples were collected.

134

Table 2. Profile descriptions for Column C.

Horizon Unit

Elev.

(m)

BSS

# TXT

Field


Calcium

Carbonate

Redoximorphic

Features Contents

Lower

Boundary

Bkss1 5 93.05-

93.15

85-

86

Clay Dry:

10 YR4/2

Dark

greyish

brown

Weak,

medium

angular

blocky


nodules and

coatings

Common, faint

brownish yellow

(10 YR 6/6)

mottles

Few roots, few

shells, few flakes,

common rounded

limestone and

chert gravels,

common cracks

Gradual,

smooth

boundary

Abss 4 92.89-

93.05

83-

84

Clay Dry:

10 YR 4/2

dark

greyish

brown

Medium,

weak

angular

blocky


nodules and

filaments

Common (15%),

distinct yellowish

brown (10 YR

5/4) mottles

Few flakes, few

rounded limestone

and chert gravels,

common cracks

Gradual,

smooth

boundary

Bkss2 3 92.72-

92.89

78-

81

Clay Dry:

10 YR 4/2

dark

greyish

brown

Medium,

moderate

angular

blocky

Very hard Common

filaments

Many (25%),

prominent yellow

(10 YR 7/6)

mottles. Fe-Mg

nodules present.

Saprolite present.

Few gravels and

flakes.

Gradual,

wavy

Bk 2 92.45-

92.72

73-

77

Clay Wet:

10 YR 5/1

gray to

10 YR 4/1

dark gray

Medium,

weak

subangular

blocky


nodules,

coatings,

filaments, and

many soft

masses

Many (20%),

prominent yellow

(10 YR 7/6)

mottles

Saprolite present,

few cracks.

Gradual,

smooth

1 Base -

92.45

68-

72

Clay Wet:

10 YR 5/1

gray to

10 YR 4/1

dark gray

Medium,

weak

subangular

blocky

Plastic (wet) Few hard

nodules;

common

coatings,

filaments, and

soft masses

Common (19%),

prominent yellow

(10 YR 7/6)

mottles

Saprolite present,

few gravels.

135

Figure 8. Geologic profile for where Column D samples were collected.

136

Table 4. Profile descriptions for Column D.

Unit

Elev.

(m)

BSS

# TXT

Field


Calcium

Carbonate

Redoximorphic

Features Contents

Lower

Boundary

The

stratigraphic

units in Column

D do not

correlate with

the stratigraphic

units seen in

Columns A, B,

or C.

92.09-

92.14

98-

99

Clay Wet:

7.5 YR

5/8 Strong

brown

To wet to

determine

Plastic (wet) Common, soft

masses

Many (50%)

GLEY 1 6/N

gray mottles

Saprolite present,

leaching from

large limestone

rocks

Clear,

smooth

92.14-

92.34

94-

97

Clay Wet:

10 YR 4/6

Strong

brown


masses

Many (50%)

GLEY 1 7/N

light gray mottles

Saprolite present,

leaching from

large limestone

rocks

Clear,

wavy

92.09-

92.14

93 Clay Wet:

10 YR 6/8

brownish

yellow to

10 YR

7/8 yellow


masses

Common (5%)

GLEY 1 6/N

gray mottles

Saprolite present,

leaching from

large limestone

rocks, common

cobbles (2-10 cm)

and gravels

137

APPENDIX B: RESULTING DATA FROM ANALYSES

The data used to generate the figures seen in the results section is provided here.

The provenience information for bulk sediment samples is show in Figure 14.

Accompanying sediment and soil horizon descriptions are presented in Appendix A.

138

Table 1. Provenience information for samples collected from Columns A through D.

BSS # Column NSWE Profile Elevation Placement

1 A West N1161 E1082 92.10-92.15 14 cm from N 2 West N1161 E1082 92.15-92.20 14 cm from N 3 West N1161 E1082 92.20-92.25 14 cm from N 4 West N1161 E1082 92.25-92.30 14 cm from N 5 West N1161 E1082 92.25-92.30 59 cm from N 6 West N1161 E1082 92.30-92.35 59 cm from N 7 West N1161 E1082 92.35-92.40 59 cm from N 8 West N1161 E1082 92.40-92.45 59 cm from N 9 West N1161 E1082 92.45-92.50 59 cm from N

10 West N1161 E1082 92.50-92.55 59 cm from N 11 West N1161 E1082 92.55-92.60 59 cm from N 12 West N1161 E1082 92.60-92.65 59 cm from N 13 West N1161 E1082 92.65-92.70 59 cm from N 14 West N1161 E1082 92.70-92.75 59 cm from N 15 West N1161 E1082 92.75-92.80 59 cm from N 16 West N1161 E1082 92.80-92.85 59 cm from N 17 West N1160 E1082 92.80-92.85 20 cm from N 18 West N1160 E1082 92.85-92.90 20 cm from N 19 West N1160 E1082 92.90-92.95 20 cm from N 20 West N1160 E1082 92.95-93.00 20 cm from N 21 West N1160 E1080 93.00-93.05 20 cm from N 22 West N1160 E1080 93.05-93.10 20 cm from N 23 West N1160 E1080 93.10-93.15 20 cm from N 24 West N1160 E1080 93.15-93.20 20 cm from N 25 West N1160 E1080 93.20-93.25 20 cm from N 26 West N1160 E1079 93.25-93.30 20 cm from N 27 West N1160 E1079 93.30-92.35 20 cm from N 28 West N1160 E1079 93.35-93.40 20 cm from N 29 West N1160 E1079 93.40-93.45 20 cm from N 30 West N1160 E1079 93.45-93.50 20 cm from N 31 West N1160 E1079 93.50-93.55 20 cm from N 32 West N1160 E1079 93.55-93.60 20 cm from N 33 West N1160 E1079 93.60-93.65 20 cm from N 34 West N1160 E1079 93.65-93.70 20 cm from N 35 West N1160 E1079 93.70-93.75 20 cm from N 36 West N1160 E1079 93.75-93.80 20 cm from N 37 West N1160 E1079 93.80-93.85 20 cm from N 38 West N1160 E1079 93.85-93.90 20 cm from N 39 West N1160 E1079 93.90-93.95 20 cm from N 40 West N1160 E1079 93.95-94.00 20 cm from N 41 West N1160 E1079 94.00-94.05 20 cm from N 42 West N1160 E1079 94.05-94.10 20 cm from N 43 West N1160 E1079 94.10-94.15 20 cm from N 44 West N1160 E1079 94.15-94.20 20 cm from N 45 West N1160 E1079 94.20-94.25 20 cm from N

46 West N1160 E1078 94.25-94.30 60 cm from N

139

Table 1, continued. Provenience information for samples collected from Columns A through D.

47 West N1160 E1078 94.30-94.35 60 cm from N 48 West N1160 E1078 94.35-94.40 60 cm from N 49 West N1160 E1078 94.40-94.45 60 cm from N 50 West N1160 E1078 94.45-94.50 60 cm from N 51 West N1160 E1078 94.50-94.55 60 cm from N 52 West N1160 E1078 94.55-94.60 60 cm from N 53 West N1160 E1078 94.60-94.65 60 cm from N 54 West N1160 E1078 94.65-94.70 60 cm from N 55 West N1160 E1078 94.70-94.75 60 cm from N 56 West N1160 E1078 94.75-94.80 60 cm from N 57 West N1160 E1078 94.80-94.90 60 cm from N

67 B North N1163 E1081 94.40-92.45 5 cm from W 66 North N1163 E1081 94.45-92.50 5 cm from W 58 North N1163 E1081 94.50-94.55 5 cm from W 59 North N1163 E1081 94.55-94.60 5 cm from W 60 North N1163 E1081 94.60-94.65 5 cm from W 61 North N1163 E1081 94.65-94.70 5 cm from W 62 North N1163 E1081 94.70-94.75 5 cm from W 63 North N1163 E1081 94.75-94.80 5 cm from W 64 North N1163 E1081 94.80-94.85 5 cm from W 65 North N1163 E1081 94.85-94.90 5 cm from W

68 C North N1162 E1083 92.20-92.25 12 cm from E 69 North N1162 E1083 92.25-92.30 12 cm from E 70 North N1162 E1083 92.30-92.35 12 cm from E 71 North N1162 E1083 92.35-92.40 12 cm from E 72 North N1162 E1083 92.40-92.45 12 cm from E 73 North N1162 E1083 92.45-92.50 12 cm from E 74 North N1162 E1083 92.50-92.55 12 cm from E 75 North N1162 E1083 92.55-92.60 12 cm from E 76 North N1162 E1083 92.60-92.65 12 cm from E 77 North N1162 E1083 92.65-92.70 12 cm from E 78 North N1162 E1083 92.70-92.75 12 cm from E 79 North N1162 E1083 92.75-92.80 12 cm from E 80 North N1162 E1083 92.80-92.85 12 cm from E 81 North N1162 E1083 92.85-92.90 12 cm from E 82 North N1162 E1083 92.90-92.95 12 cm from E 83 North N1162 E1083 92.95-93.00 12 cm from E 84 North N1162 E1083 93.00-93.05 12 cm from E 85 North N1162 E1083 93.05-93.10 12 cm from E 86 North N1162 E1083 93.10-93.15 12 cm from E

93 D Pedestalled Rocks: South 92.09-92.155 94 Pedestalled Rocks: South 92.155-92.19 95 Pedestalled Rocks: South 92.19-92.24 96 Pedestalled Rocks: South 92.24-92.29 97 Pedestalled Rocks: South 92.29-92.34 98 Pedestalled Rocks: South 92.34-92.39 99 Pedestalled Rocks: South 92.39-92.44

14

0

Table 2. Results of the sieve-hydrometer and Chittick analyses for Column A.

Stratigraphic Unit

BSS #

Avg. Depth

Gravel (%)

Sand (%)

Silt (%)

Clay (%)

Mean (phi)

SD

Sand (%)

Silt (%)

Clay (%)

Texture Class

Chittick (%CaCO3)

1 1 92.125 55.95 17.48 9.33 17.24 2.11 7.71 39.67 21.18 39.15 Clay Loam 25.69

2 92.175 39.44 17.63 18.07 24.86 3.49 7.58 29.17 29.83 41.00 Clay 27.84

3 92.225 17.63 16.33 29.20 36.84 5.37 6.64 19.83 35.43 44.74 Clay 24.80

4 92.275 21.01 15.62 28.98 34.39 4.88 7.01 19.75 36.71 43.54 Silty Clay Loam 28.44

5 92.275 25.92 26.36 23.84 23.88 4.90 5.99 35.58 32.16 32.26 Clay Loam 50.17

6 92.325 24.99 23.20 24.82 26.99 4.60 6.64 30.92 33.08 36.00 Clay Loam 42.96

2 7 92.375 24.56 22.74 24.72 27.98 4.58 6.74 30.17 32.75 37.08 Clay Loam 28.44

8 92.425 19.68 25.46 23.15 31.71 5.14 6.59 31.68 28.84 39.48 Clay Loam 38.76

9 92.475 16.94 21.63 28.46 32.97 5.31 6.44 26.03 34.27 39.70 Clay Loam 33.06

3 10 92.525 17.36 17.52 30.01 35.11 5.35 6.62 21.18 36.32 42.50 Clay 25.42

11 92.575 28.17 8.45 38.57 24.81 3.84 7.25 11.76 53.70 34.54 Silty Clay Loam 19.40

12 92.625 18.58 8.56 30.73 42.13 5.09 7.21 10.50 37.76 51.74 Clay 10.92

13 92.675 31.12 3.57 40.34 24.97 3.63 7.42 5.20 58.56 36.24 Silty Clay Loam 7.58

14 92.725 19.80 6.01 23.64 50.55 4.71 7.86 7.51 29.48 63.01 Clay 7.59

15 92.775 26.60 4.97 24.79 43.64 4.02 8.31 6.76 33.76 59.48 Clay 3.67

4 16 92.825 14.23 5.30 28.30 52.17 6.54 6.06 6.16 33.01 60.83 Clay 3.94

17 92.825 17.05 6.97 26.74 49.24 5.51 7.04 8.40 32.23 59.37 Clay 7.59

18 92.875 0.60 6.94 32.46 60.00 8.98 3.82 6.99 32.66 60.35 Clay 4.25

19 92.925 13.07 8.23 27.90 50.80 8.93 3.84 9.49 32.10 58.41 Clay 8.49

5 20 92.975 0.47 12.00 30.81 56.72 8.72 4.03 12.08 30.96 56.96 Clay 13.34

21 93.025 1.69 10.64 33.11 54.56 8.72 3.98 10.84 33.68 55.48 Clay 13.95

22 93.075 1.29 10.97 32.77 54.97 8.73 3.99 11.09 33.17 55.74 Clay 14.55

23 93.125 1.70 11.41 30.17 56.72 8.96 3.79 11.61 30.70 57.69 Clay 16.66

24 93.175 2.15 11.21 29.13 57.51 10.19 2.59 11.46 29.75 58.79 Clay 14.25

6 25 93.225 1.72 11.14 30.89 56.25 8.77 3.97 11.33 31.43 57.24 Clay 7.95

14

1

Table 2, continued. Results of the sieve-hydrometer and Chittick analyses for Column A.

Stratigraphic Unit

BSS #

Avg. Depth

Gravel (%)

Sand (%)

Silt (%)

Clay (%)

Mean (phi)

SD

Sand (%)

Silt (%)

Clay (%)

Texture Class

Chittick (%CaCO3)

6, continued 26 93.275 2.39 10.01 45.29 42.31 8.31 4.00 10.25 46.40 43.35 Silty Clay 17.02

27 93.325 0.24 13.59 31.58 54.59 8.54 4.14 13.62 31.66 54.72 Clay 15.19

28 93.375 2.29 13.34 29.10 55.27 8.57 4.16 13.65 29.77 56.58 Clay 13.97

29 93.425 25.40 11.05 21.78 41.77 8.50 4.21 14.82 29.19 55.99 Clay 19.74

30 93.475 1.74 12.80 29.13 56.33 8.63 4.13 13.01 29.64 57.35 Clay 22.78

31 93.525 1.37 10.24 30.11 58.28 9.00 3.81 10.39 30.51 59.10 Clay 18.35

7 32 93.575 4.88 5.98 43.52 45.62 8.54 4.00 6.27 45.74 47.99 Silty Clay 13.45

33 93.625 3.47 7.21 30.16 59.16 9.23 3.63 7.45 31.24 61.31 Clay 8.85

34 93.675 0.50 8.51 28.40 62.59 9.44 3.44 8.56 28.55 62.89 Clay 14.56

35 93.725 1.69 6.67 31.42 60.22 9.16 3.43 6.78 31.96 61.26 Clay 7.89

36 93.775 4.93 5.99 30.02 59.06 9.36 3.52 6.29 31.56 62.15 Clay 1.21

37 93.825 0.47 5.96 33.02 60.55 9.42 3.42 6.01 33.18 60.81 Clay 6.68

38 93.875 2.63 5.56 33.04 58.77 9.06 3.72 5.73 33.94 60.33 Clay 9.09

39 93.925 11.58 5.17 30.47 52.78 8.03 4.60 5.88 34.47 59.65 Clay 7.87

40 93.975 11.21 5.49 29.88 53.42 8.01 4.63 6.19 33.67 60.14 Clay 6.90

8 41 94.025 2.13 6.45 33.31 58.11 9.89 2.90 6.55 34.05 59.40 Clay 5.49

42 94.075 0.50 4.94 33.88 60.68 9.31 3.52 4.95 34.06 60.99 Clay 4.26

43 94.125 10.90 4.32 29.65 55.13 8.45 4.26 4.87 33.27 61.86 Clay 2.75

44 94.175 10.15 4.74 30.49 54.62 8.47 4.22 5.27 33.95 60.78 Clay 3.66

9 45 94.225 2.62 5.63 32.65 59.10 9.17 3.64 5.79 33.53 60.68 Clay 4.20

46 94.275 0.76 7.52 32.67 59.05 9.29 3.52 7.58 32.91 59.51 Clay 5.40

47 94.325 1.10 5.16 32.93 60.81 9.45 3.40 5.23 33.29 61.48 Clay 2.42

48 94.375 1.07 5.60 33.48 59.85 9.26 3.56 5.68 33.84 60.48 Clay 1.82

49 94.425 3.57 7.16 31.86 57.41 8.84 3.92 7.40 33.04 59.56 Clay 4.27

disturbed 50 94.475 2.41 7.17 32.87 57.55 9.15 3.63 7.35 33.68 58.97 Clay 3.63

14

2

Table 2, continued. Results of the sieve-hydrometer and Chittick analyses for Column A.

Stratigraphic Unit

BSS #

Avg. Depth

Gravel (%)

Sand (%)

Silt (%)

Clay (%)

Mean (phi)

SD

Sand (%)

Silt (%)

Clay (%)

Texture Class

Chittick (%CaCO3)

disturbed 51 94.525 2.99 6.67 34.82 55.52 9.00 3.75 6.87 35.89 57.24 Clay 4.84 52 94.575 1.07 8.44 26.99 63.50 9.49 3.36 8.54 27.28 64.18 Clay 4.24 53 94.625 1.60 5.97 28.32 64.11 9.52 3.33 6.06 28.79 65.15 Clay 4.24 54 94.675 2.99 3.88 42.95 50.18 8.42 4.11 4.01 44.27 51.72 Silty Clay 3.33 55 94.725 4.86 4.30 28.10 62.74 9.36 3.50 4.51 29.55 65.94 Clay 1.81 56 94.775 0.96 4.50 29.88 64.66 9.65 3.24 4.57 30.18 65.25 Clay 1.21 57 94.85 1.18 3.97 31.16 63.69 9.55 3.32 4.00 31.53 64.47 Clay 1.21

Table 3. Results of the sieve-hydrometer and Chittick analyses for Column B.

Stratigraphic Unit

BSS #

Avg. Depth

Gravel (%)

Sand (%)

Silt (%)

Clay (%)

Mean (phi)

SD

Sand (%)

Silt (%)

Clay (%)

Texture Class

Chittick (%CaCO3)

9 67 94.425 2.8 3.6 35.7 57.9 9.18 3.59 3.7 36.7 40.4 Clay 3.00

Snail Hash 66 94.475 2.0 4.1 34.9 59.0 9.31 3.48 4.2 35.6 39.8 Clay 4.20 58 94.525 2.5 3.6 44.9 49.0 8.51 4.00 3.7 46.0 49.7 Silty Clay 3.63

9, continued 59 94.575 4.2 5.1 33.8 56.8 9.69 3.03 5.4 35.3 40.7 Clay 5.44 60 94.625 2.6 4.2 51.2 42.0 8.30 3.98 4.3 52.6 56.9 Silty Clay 9.06

10 61 94.675 3.1 6.5 37.0 53.4 8.92 3.66 6.7 38.2 44.9 Clay 7.81 62 94.725 7.3 4.4 35.9 52.4 8.85 3.66 4.7 38.8 43.4 Clay 3.30

63 94.775 7.1 4.4 36.8 51.7 8.83 3.63 4.8 39.6 44.4 Clay 1.80 64 94.825 7.7 3.4 37.7 51.2 8.78 3.71 3.7 40.8 44.5 Silty Clay 1.80

65 94.875 5.4 3.1 40.5 51.0 8.96 3.52 3.3 42.8 46.1 Silty Clay 1.80

14

3

Table 4. Results of the sieve-hydrometer and Chittick analyses for Column C.

Stratigraphic Unit

BSS #

Avg. Depth

Gravel (%)

Sand (%)

Silt (%)

Clay (%)

Mean (phi)

SD

Sand (%)

Silt (%)

Clay (%)

Texture Class

Chittick (%CaCO3)

1 68 92.225 3.28 8.54 39.30 48.88 8.54 3.97 8.8 40.6 49.5 Silty Clay 10.21 69 92.275 13.06 12.07 32.30 42.57 6.05 6.23 13.9 37.2 51.0 Clay 17.60

70 92.325 16.28 16.25 27.22 40.25 5.55 6.60 19.4 32.5 51.9 Clay 24.88 71 92.375 20.03 23.41 21.62 34.94 5.31 6.63 29.3 27.0 56.3 Clay 36.41 72 92.425 28.28 18.55 20.18 32.99 4.89 6.88 25.9 28.1 54.0 Clay 35.19

2 73 92.475 25.09 19.18 20.80 34.93 5.02 6.90 25.6 27.8 53.4 Clay 30.31 74 92.525 20.59 20.01 21.88 37.52 4.78 6.23 25.2 27.5 52.7 Clay 33.93 75 92.575 24.83 17.95 22.70 34.52 4.89 6.94 23.9 30.2 54.1 Clay 35.78 76 92.625 22.42 17.33 22.04 38.21 5.10 7.01 22.3 28.4 50.7 Clay 32.16 77 92.675 22.69 21.25 19.71 36.35 5.62 6.40 27.5 25.5 53.0 Clay 40.00

3 78 92.725 25.82 14.37 30.49 29.32 4.27 6.76 19.37 41.13 60.5 Silty Clay Loam 30.33 79 92.775 25.37 14.99 22.58 37.06 4.76 7.24 20.07 30.25 50.3 Clay 25.46

80 92.825 25.00 10.50 17.87 46.63 4.89 7.71 14.00 23.81 37.8 Clay 19.41 81 92.875 22.26 7.44 20.42 49.88 4.71 7.96 9.57 26.26 35.8 Clay 15.78

4 82 92.925 12.09 9.21 21.42 57.28 6.51 6.35 10.49 24.37 34.9 Clay 10.91 83 92.975 29.70 5.02 33.20 32.08 4.36 7.58 7.15 47.24 45.61 Silty Clay 10.92

84 93.025 0.13 5.93 25.49 68.45 9.61 3.46 5.97 25.53 31.5 Clay 6.98

5 85 93.075 0.24 5.99 26.59 67.18 9.55 3.49 6.00 26.65 32.7 Clay 6.04 86 93.125 2.32 5.27 45.60 46.81 8.28 4.33 5.41 46.69 52.1 Silty Clay 6.64

14

4

Table 5. Results of the sieve-hydrometer and Chittick analyses for Column D.

Stratigraphic Unit

BSS #

Avg. Depth

Gravel (%)

Sand (%)

Silt (%)

Clay (%)

Mean (phi)

SD

Sand (%)

Silt (%)

Clay (%)

Texture Class

Chittick (%CaCO3)

These units do not

correlate with the other

stratigraphic units

discussed here

93 92.1225 19.56 18.18 25.12 37.14 5.18 6.97 22.6 31.2 53.8 Clay 18.71

94 92.1725 3.76 11.91 33.34 50.99 8.35 4.28 12.4 34.7 47.0 Clay 16.29

95 92.215 6.37 14.05 32.12 47.46 6.98 5.19 15.0 34.3 49.3 Clay 23.23

96 92.265 15.08 17.87 26.36 40.69 5.73 6.53 21.0 31.0 52.1 Clay 27.78

97 92.315 14.76 19.73 27.19 38.32 6.44 5.28 23.2 31.9 55.0 Clay 35.02

98 92.365 13.90 23.07 26.42 36.61 5.76 6.30 26.8 30.7 57.5 Clay 41.66

99 92.415 13.80 21.72 25.71 38.77 5.85 6.38 25.2 29.8 55.0 Clay 32.61

145

Table 6. Results of the Loss-On-Ignition analysis for Column A.

BSS #

Avg. Depth Moist

Dry 105˚

Ashed 400˚

Ashed 950˚ Water

SOM LOI

Weight 400˚

CaCO3 LOI

Weight 950˚

(m) (g) (g) (g) (g) (%) (%) loss (g) (%) loss (g)

1 92.125 9.06 8.52 8.28 7.46 6.34 2.82 0.24 9.90 0.82

2 92.175 10.00 9.38 9.08 8.06 6.61 3.20 0.30 11.23 1.02

3 92.225 10.01 9.25 8.92 7.92 8.22 3.57 0.33 11.21 1.00

4 92.275 10.02 9.28 8.95 7.84 7.97 3.56 0.33 12.40 1.11

5 92.275 10.00 9.46 9.18 7.46 5.71 2.96 0.28 18.74 1.72

6 92.325 10.00 9.38 9.11 7.49 6.61 2.88 0.27 17.78 1.62

7 92.375 10.00 9.20 8.94 7.45 8.70 2.83 0.26 16.67 1.49

8 92.425 10.00 9.28 8.98 7.50 7.76 3.23 0.30 16.48 1.48

9 92.475 10.00 9.18 8.85 7.56 8.93 3.59 0.33 14.58 1.29

10 92.525 10.00 9.16 8.83 7.69 9.17 3.60 0.33 12.91 1.14

11 92.575 10.01 9.15 8.84 8.06 9.40 3.39 0.31 8.82 0.78

12 92.625 10.00 9.13 8.77 8.31 9.53 3.94 0.36 5.25 0.46

13 92.675 10.01 9.17 8.79 8.40 9.16 4.14 0.38 4.44 0.39

14 92.725 10.01 9.15 8.76 8.34 9.40 4.26 0.39 4.79 0.42

15 92.775 10.00 9.01 8.66 8.30 10.99 3.88 0.35 4.16 0.36

16 92.825 10.00 9.10 8.70 8.47 9.89 4.40 0.40 2.64 0.23

17 92.825 10.00 9.10 8.73 8.32 9.89 4.07 0.37 4.70 0.41

18 92.875 10.00 9.03 8.68 8.31 10.74 3.88 0.35 4.26 0.37

19 92.925 10.00 9.06 8.64 8.16 10.38 4.64 0.42 5.56 0.48

20 92.975 10.00 9.06 8.68 8.04 10.38 4.19 0.38 7.37 0.64

21 93.025 10.00 9.05 8.69 8.03 10.50 3.98 0.36 7.59 0.66

22 93.075 10.01 8.92 8.56 7.86 12.22 4.04 0.36 8.18 0.70

23 93.125 10.01 9.03 8.65 7.95 10.85 4.21 0.38 8.09 0.70

24 93.175 10.01 9.15 8.72 8.08 9.40 4.70 0.43 7.34 0.64

25 93.225 10.04 9.08 8.80 8.26 10.57 3.08 0.28 6.14 0.54

26 93.275 10.00 8.97 8.67 7.99 11.48 3.34 0.30 7.84 0.68

27 93.325 10.00 9.06 8.76 8.01 10.38 3.31 0.30 8.56 0.75

28 93.375 10.00 9.06 8.76 8.02 10.38 3.31 0.30 8.45 0.74

29 93.425 10.09 9.05 8.75 7.88 11.49 3.31 0.30 9.94 0.87

30 93.475 10.01 9.12 8.81 7.86 9.76 3.40 0.31 10.78 0.95

31 93.525 10.03 9.13 8.80 7.90 9.86 3.61 0.33 10.23 0.90

32 93.575 10.14 9.23 8.86 8.09 9.86 4.01 0.37 8.69 0.77

33 93.625 10.04 8.97 8.62 8.02 11.93 3.90 0.35 6.96 0.60

34 93.675 9.99 9.02 8.69 8.00 10.75 3.66 0.33 7.94 0.69

35 93.725 9.98 9.04 8.68 8.16 10.40 3.98 0.36 5.99 0.52

36 93.775 10.08 9.11 8.74 8.18 10.65 4.06 0.37 6.41 0.56

37 93.825 10.05 9.16 8.79 8.29 9.72 4.04 0.37 5.69 0.50

38 93.875 10.00 9.08 8.70 8.14 10.13 4.19 0.38 6.44 0.56

146

Table 6, continued. Results of the Loss-On-Ignition analysis for Column A.

BSS #

Avg. Depth Moist

Dry 105˚

Ashed 400˚

Ashed 950˚ Water

SOM LOI

Weight 400˚

CaCO3 LOI

Weight 950˚


40 93.975 10.00 9.12 8.71 8.24 9.65 4.50 0.41 5.40 0.47

41 94.025 10.03 9.12 8.72 8.32 9.98 4.39 0.40 4.59 0.40

42 94.075 10.01 9.03 8.62 8.30 10.85 4.54 0.41 3.71 0.32

43 94.125 10.37 9.36 8.95 8.62 10.79 4.38 0.41 3.69 0.33

44 94.175 10.01 9.08 8.65 8.34 10.24 4.74 0.43 3.58 0.31

45 94.225 9.99 8.82 8.43 8.06 13.27 4.42 0.39 4.39 0.37

46 94.275 10.01 8.95 8.58 8.11 11.84 4.13 0.37 5.48 0.47

47 94.325 10.04 9.03 8.66 8.33 11.18 4.10 0.37 3.81 0.33

48 94.375 10.01 9.08 8.66 8.31 10.24 4.63 0.42 4.04 0.35

49 94.425 9.94 8.97 8.63 8.23 10.81 3.79 0.34 4.63 0.40

50 94.475 10.03 9.10 8.75 8.32 10.22 3.85 0.35 4.91 0.43

51 94.525 9.99 9.11 8.74 8.30 9.66 4.06 0.37 5.03 0.44

52 94.575 9.99 9.08 8.71 8.23 10.02 4.07 0.37 5.51 0.48

53 94.625 9.99 9.06 8.65 8.26 10.26 4.53 0.41 4.51 0.39

54 94.675 10.02 9.08 8.72 8.34 10.35 3.96 0.36 4.36 0.38

55 94.725 10.03 9.08 8.70 8.37 10.46 4.19 0.38 3.79 0.33

56 94.775 9.98 8.98 8.56 8.28 11.14 4.68 0.42 3.27 0.28

57 94.85 10.03 9.01 8.50 8.20 11.32 5.66 0.51 3.53 0.30

Table 7. Results of the Loss-On-Ignition analysis for Column B.

BSS #

Avg. Depth Moist

Dry 105˚

Ashed 400˚

Ashed 950˚ Water

SOM LOI

Weight 400˚

CaCO3 LOI

Weight 950˚


67 94.425 10.00 9.26 8.78 8.40 7.99 5.18 0.48 4.33 0.38

66 94.475 10.01 9.20 8.70 8.27 8.80 5.43 0.50 4.94 0.43

58 94.525 9.98 8.89 8.37 7.95 12.26 5.85 0.52 5.02 0.42

59 94.575 10.04 8.95 8.41 7.87 12.18 6.03 0.54 6.42 0.54

60 94.625 10.02 8.97 8.39 7.83 11.71 6.47 0.58 6.67 0.56

61 94.675 10.01 9.34 8.71 8.06 7.17 6.75 0.63 7.46 0.65

62 94.725 10.02 9.24 8.61 8.18 8.44 6.82 0.63 4.99 0.43

63 94.775 9.99 9.20 8.55 8.16 8.59 7.07 0.65 4.56 0.39

64 94.825 10.02 9.23 8.53 8.22 8.56 7.58 0.70 3.63 0.31

65 94.875 10.02 9.26 8.57 8.16 8.21 7.45 0.69 4.78 0.41

147

Table 8. Results of the Loss-On-Ignition analysis for Column C.

BSS #

Avg. Depth Moist

Dry 105˚

Ashed 400˚

Ashed 950˚ Water

SOM LOI

Weight 400˚

CaCO3 LOI

Weight 950˚


68 92.225 10.02 9.46 9.17 8.61 5.92 3.07 0.29 6.11 0.56

69 92.275 10.01 9.45 9.19 8.25 5.93 2.75 0.26 10.23 0.94

70 92.325 10.02 9.48 9.26 8.11 5.70 2.32 0.22 12.42 1.15

71 92.375 10.00 9.41 9.22 7.64 6.27 2.02 0.19 17.14 1.58

72 92.425 9.99 9.48 9.28 7.75 5.38 2.11 0.20 16.49 1.53

73 92.475 10.00 9.49 9.24 7.92 5.37 2.63 0.25 14.29 1.32

74 92.525 10.06 9.49 9.27 7.92 6.01 2.32 0.22 14.56 1.35

75 92.575 10.02 9.49 9.27 7.85 5.58 2.32 0.22 15.32 1.42

76 92.625 10.03 9.48 9.26 7.94 5.80 2.32 0.22 14.25 1.32

77 92.675 10.00 9.39 9.14 7.53 6.50 2.66 0.25 17.61 1.61

78 92.725 10.00 9.32 9.06 7.81 7.30 2.79 0.26 13.80 1.25

79 92.775 10.04 9.06 8.83 7.75 10.82 2.54 0.23 12.23 1.08

80 92.825 10.02 9.22 8.95 8.07 8.68 2.93 0.27 9.83 0.88

81 92.875 10.02 9.30 8.97 8.22 7.74 3.55 0.33 8.36 0.75

82 92.925 10.04 9.28 8.97 8.31 8.19 3.34 0.31 7.36 0.66

83 92.975 10.00 9.22 8.88 8.19 8.46 3.69 0.34 7.77 0.69

84 93.025 10.00 9.24 8.88 8.41 8.23 3.90 0.36 5.29 0.47

85 93.075 9.99 9.24 8.85 8.36 8.12 4.22 0.39 5.54 0.49

86 93.125 10.06 9.34 9.00 8.42 7.70 3.64 0.34 6.44 0.58

Table 9. Results of the Loss-On-Ignition analysis for Column D.

BSS #

Avg. Depth Moist

Dry 105˚

Ashed 400˚

Ashed 950˚ Water

SOM LOI

Weight 400˚

CaCO3 LOI

Weight 950˚


93 92.1225 10.05 9.51 9.25 8.25 5.68 2.73 0.26 10.81 1.00

94 92.1725 10.03 9.41 9.14 8.29 6.59 2.87 0.27 9.30 0.85

95 92.215 9.98 9.41 9.13 8.03 6.06 2.98 0.28 12.05 1.10

96 92.265 10.02 9.44 9.16 7.94 6.14 2.97 0.28 13.32 1.22

97 92.315 10.03 9.49 9.22 7.76 5.69 2.85 0.27 15.84 1.46

98 92.365 10.05 9.52 9.25 7.64 5.57 2.84 0.27 17.41 1.61

99 92.415 10.00 9.53 9.28 7.88 4.93 2.62 0.25 15.09 1.40

148

Table 10. Results of the Walkley Black analysis for Column A.

BSS #

Avg. Depth

FeSO4 to Blank

FeSO4 to Sample SOC

BSS #

Avg. Depth

FeSO4 to Blank

FeSO4 to Sample SOC

(m) (mL) (mL) (%)

(m) (mL) (mL) (%)

1 92.125 39 93.925 19.0 16.5 0.45

2 92.175 21.8 18.4 0 40 93.975 19.0 14.8 0.75

3 92.225 19.0 18.1 0.16 41 94.025 19.0 15.5 0.62

4 92.275 19.0 18.6 0.07 42 94.075 19.0 16.4 0.46

5 92.275 19.0 18.1 0.16 43 94.125 19.0 15.1 0.70

6 92.325 19.0 18.3 0.12 44 94.175 19.0 15.2 0.68

7 92.375 19.0 17.7 0.23 45 94.225 19.0 14.8 0.75

8 92.425 19.0 18.5 0.09 46 94.275 19.0 15.4 0.64

9 92.475 19.0 18.1 0.16 47 94.325 19.0 15.7 0.59

10 92.525 19.0 18.0 0.18 48 94.375 19.0 15.7 0.59

11 92.575 19.0 18.4 0.11 49 94.425 19.0 15.6 0.61

12 92.625 19.0 18.0 0.18 50 94.475 19.0 14.5 0.80

13 92.675 19.0 16.1 0.52 51 94.525 19.0 14.9 0.73

14 92.725 19.0 18.5 0.09 52 94.575 21.8 16.5 0.75

15 92.775 19.0 17.7 0.23 53 94.625 21.8 14.8 0.72

16 92.825 19.0 17.9 0.20 54 94.675 21.8 15.5 0.81

17 92.825 19.0 18.0 0.18 55 94.725 21.8 16.4 0.82

18 92.875 19.0 17.7 0.23 56 94.775 21.8 15.1 0.95

19 92.925 19.0 17.9 0.20 57 94.85 21.8 15.2 2.07

20 92.975 19.0 16.5 0.45

21 93.025 19.0 17.1 0.34

22 93.075 19.0 17.2 0.32

23 93.125 19.0 17.0 0.36

24 93.175 19.0 17.8 0.21

25 93.225

26 93.275 21.8 17.6 0.15

27 93.325 19.0 17.0 0.36

28 93.375 19.0 16.8 0.39

29 93.425 19.0 17.0 0.36

30 93.475 21.8 17.1 0.24

31 93.525 19.0 15.4 0.64

32 93.575 19.0 16.7 0.41

33 93.625 19.0 16.3 0.48

34 93.675 19.0 16.4 0.46

35 93.725 19.0 16.0 0.54

36 93.775 19.0 15.8 0.57

37 93.825 19.0 16.7 0.41

38 93.875 19.0 15.4 0.64

149

Table 11. Results of the Walkley Black analysis for Column B.

19.0

BSS #

Avg. Depth

FeSO4 to Blank

FeSO4 to Sample SOC

BSS #

Avg. Depth

FeSO4 to Blank

FeSO4 to Sample SOC

(m) (mL) (mL) (%)

(m) (mL) (mL) (%)

67 94.425 21.8 14.1 1.20 61 94.675 21.8 6.0 2.46

66 94.475 21.8 62 94.725 21.8 5.4 2.55

58 94.525 21.8 8.5 2.07 63 94.775 21.8 5.8 2.49

59 94.575 21.8 7.5 2.22 64 94.825 21.8 5.9 2.47

60 94.625 21.8 6.9 2.32 65 94.875

Table 12. Results of the Walkley Black analysis for Column C.

BSS #

Avg. Depth

FeSO4 to Blank

FeSO4 to Sample SOC

BSS #

Avg. Depth

FeSO4 to Blank

FeSO4 to Sample SOC

(m) (mL) (mL) (%)

(m) (mL) (mL) (%)

68 92.225 21.8 20.0 0.28 78 92.725 21.8 17.8 0.62

69 92.275 79 92.775 21.8 17.3 0.70

70 92.325 80 92.825 21.8 17.2 0.72

71 92.375 21.8 20.2 0.25 81 92.875 21.8 18.5 0.51

72 92.425 21.8 20.5 0.20 82 92.925 21.8 14.7 1.10

73 92.475 21.8 20.5 0.20 83 92.975 21.8 16.2 0.87

74 92.525 21.8 20.7 0.17 84 93.025 21.8 16.8 0.78

75 92.575 21.8 19.6 0.34 85 93.075 21.8 16.6 0.81

76 92.625 21.8 19.7 0.33 86 93.125 21.8 16.6 0.81

77 92.675 21.8 19.8 0.31

Table 13. Results of the Walkley Black analysis for Column D.

BSS #

Avg. Depth

FeSO4 to Blank

FeSO4 to Sample SOC

BSS #

Avg. Depth

FeSO4 to Blank

FeSO4 to Sample SOC

(m) (mL) (mL) (%) (m) (mL) (mL) (%)

93 92.1225 21.8 18.5 0.51 97 92.315 21.8 18.1 0.58

94 92.1725 21.8 18.4 0.53 98 92.365 21.8 18.2 0.56

95 92.215 21.8 18.5 0.51 99 92.415 21.8 18 0.59

96 92.265 21.8 18.4 0.53

150

Table 14. Results of the magnetic susceptibility analysis for Column A.

BSS# Depth Mass HF

Average LF

Average Xlf Xhf Xfd

(m) (g) (10-8m3kg-1) (10-8m3kg-1)

1 92.10-92.15 9.04 3.75 3.55 3.93 4.15 -5.63

2 92.15-92.20 9.20 5.50 4.90 5.33 5.98 -12.24

3 92.20-92.25 9.04 6.90 5.00 5.53 7.63 -38.00

4 92.25-92.30 9.37 7.00 6.90 7.36 7.47 -1.45

5 92.25-92.30 10.35 6.90 4.80 4.64 6.67 -43.75

6 92.30-92.35 7.93 4.30 3.80 4.79 5.42 -13.16

7 92.35-92.40 10.32 7.70 6.30 6.10 7.46 -22.22

8 92.40-92.45 9.17 5.80 5.55 6.05 6.32 -4.50

9 92.45-92.50 8.33 5.40 5.70 6.84 6.48 5.26

10 92.50-92.55 8.33 5.20 6.60 7.92 6.24 21.21

11 92.55-92.60 8.33 6.65 7.40 8.88 7.98 10.14

12 92.60-92.65 8.51 11.95 7.75 9.11 14.04 -54.19

13 92.65-92.70 6.44 6.90 5.35 8.31 10.71 -28.97

14 92.70-92.75 6.75 2.85 5.25 7.78 4.22 45.71

15 92.75-92.80 7.07 20.20 24.60 34.79 28.57 17.89

16 92.80-92.85 7.40 5.40 6.25 8.45 7.30 13.60

17 92.80-92.85 7.09 8.60 6.45 9.10 12.13 -33.33

18 92.85-92.90 6.63 6.35 6.50 9.80 9.58 2.31

19 92.90-92.95 7.37 7.10 7.05 9.57 9.63 -0.71

20 92.95-93.00 7.50 3.65 7.20 9.60 4.87 49.31

21 93.00-93.05 6.46 9.00 8.95 13.85 13.93 -0.56

22 93.05-93.10 6.00 6.15 8.45 14.08 10.25 27.22

23 93.10-93.15 7.56 6.75 8.10 10.71 8.93 16.67

24 93.15-93.20 7.42 9.40 11.15 15.03 12.67 15.70

25 93.20-93.25 6.49 6.40 6.25 9.63 9.86 -2.40

26 93.25-93.30 6.39 5.80 6.25 9.78 9.08 7.20

27 93.30-92.35 6.68 6.95 7.75 11.60 10.40 10.32

28 93.35-93.40 6.84 8.60 7.70 11.26 12.57 -11.69

29 93.40-93.45 6.98 7.65 6.75 9.67 10.96 -13.33

30 93.45-93.50 7.08 3.45 5.85 8.26 4.87 41.03

31 93.50-93.55 6.51 7.00 7.35 11.29 10.75 4.76

32 93.55-93.60 7.08 6.50 6.25 8.83 9.18 -4.00

33 93.60-93.65 6.51 9.75 7.15 10.98 14.98 -36.36

34 93.65-93.70 6.74 9.05 7.75 11.50 13.43 -16.77

35 93.70-93.75 6.88 4.85 10.65 15.48 7.05 54.46

36 93.75-93.80 6.48 16.35 16.75 25.85 25.23 2.39

37 93.80-93.85 7.05 7.80 10.80 15.32 11.06 27.78

38 93.85-93.90 6.77 11.10 12.55 18.54 16.40 11.55

151

Table 14, continued. Results of the magnetic susceptibility analysis for Column A.

BSS# Depth Mass HF

Average LF

Average Xlf Xhf Xfd

(m) (g) (10-8m3kg-1)

39 93.90-93.95 7.22 15.70 18.95 26.25 21.75 17.15

40 93.95-94.00 6.78 18.40 21.50 31.71 27.14 14.42

41 94.00-94.05 7.04 27.20 30.60 43.47 38.64 11.11

42 94.05-94.10 6.38 26.95 27.70 43.42 42.24 2.71

43 94.10-94.15 6.64 25.40 28.55 43.00 38.25 11.03

44 94.15-94.20 7.48 23.70 28.80 38.50 31.68 17.71

45 94.20-94.25 6.56 25.55 30.35 46.27 38.95 15.82

46 94.25-94.30 6.69 26.10 30.30 45.29 39.01 13.86

47 94.30-94.35 6.60 26.10 31.75 48.11 39.55 17.80

48 94.35-94.40 6.92 29.25 32.60 47.11 42.27 10.28

49 94.40-94.45 7.12 31.70 30.15 42.35 44.52 -5.14

50 94.45-94.50 6.57 19.25 24.45 37.21 29.30 21.27

51 94.50-94.55 7.27 20.65 28.30 38.93 28.40 27.03

52 94.55-94.60 6.98 32.45 36.40 52.15 46.49 10.85

53 94.60-94.65 7.36 29.50 42.30 57.47 40.08 30.26

54 94.65-94.70 6.65 34.95 41.70 62.71 52.56 16.19

55 94.70-94.75 7.51 55.75 61.75 82.22 74.23 9.72

56 94.75-94.80 6.78 50.10 53.05 78.24 73.89 5.56

57 94.80-94.90 6.92 73.10 82.20 118.79 105.64 11.07

Table 15. Results of the magnetic susceptibility analysis for Column B.

BSS# Depth Mass HF

Average LF

Average Xlf Xhf Xfd

(m) (g) (10-8m3kg-1) (10-8m3kg-1)

67 94.40-92.45 6.83 65.15 76.40 111.86 95.39 14.73

66 94.45-92.50 6.93 70.55 81.20 117.17 101.80 13.12

58 94.50-94.55 6.75 77.00 88.55 131.19 114.07 13.04

59 94.55-94.60 7.04 89.00 106.70 151.56 126.42 16.59

60 94.60-94.65 6.96 96.10 105.65 151.80 138.07 9.04

61 94.65-94.70 6.78 97.00 114.45 168.81 143.07 15.25

62 94.70-94.75 7.31 113.95 136.45 186.66 155.88 16.49

63 94.75-94.80 6.85 128.55 142.55 208.10 187.66 9.82

64 94.80-94.85 6.91 122.65 145.10 209.99 177.50 15.47

65 94.85-94.90 6.70 127.40 140.10 209.10 190.15 9.06

152

Table 16. Results of the magnetic susceptibility analysis for Column C.

BSS# Depth Mass HF

Average LF

Average Xlf Xhf Xfd

(m) (g) (10-8m3kg-1) (10-8m3kg-1)

68 92.20-92.25 8.78 6.70 6.35 7.23 7.63 -5.51

69 92.25-92.30 8.91 3.60 6.20 6.96 4.04 41.94

70 92.30-92.35 9.19 3.40 6.55 7.13 3.70 48.09

71 92.35-92.40 8.63 5.05 4.70 5.45 5.85 -7.45

72 92.40-92.45 8.79 4.60 4.85 5.52 5.23 5.15

73 92.45-92.50 7.26 2.30 5.05 6.96 3.17 54.46

74 92.50-92.55 7.04 4.50 6.40 9.09 6.39 29.69

75 92.55-92.60 9.20 5.15 6.60 7.17 5.60 21.97

76 92.60-92.65 6.61 5.90 5.65 8.55 8.93 -4.42

77 92.65-92.70 7.14 4.05 5.60 7.84 5.67 27.68

78 92.70-92.75 6.68 6.65 6.60 9.88 9.96 -0.76

79 92.75-92.80 6.88 7.35 6.85 9.96 10.68 -7.30

80 92.80-92.85 7.30 6.45 6.65 9.11 8.84 3.01

81 92.85-92.90 6.97 10.45 10.75 15.42 14.99 2.79

82 92.90-92.95 7.28 12.10 12.80 17.58 16.62 5.47

83 92.95-93.00 6.91 12.70 13.05 18.89 18.38 2.68

84 93.00-93.05 6.49 13.70 14.15 21.80 21.11 3.18

85 93.05-93.10 7.04 13.95 18.90 26.85 19.82 26.19

86 93.10-93.15 7.68 24.50 26.05 33.92 31.90 5.95

Table 17. Results of the magnetic susceptibility analysis for Column D.

BSS# Depth Mass HF

Average LF

Average Xlf Xhf Xfd

(m) (g) (10-8m3kg-1) (10-8m3kg-1)

93 92.09-92.155 9.29 3.85 5.00 5.38 4.14 23.00

94 92.155-92.19 8.26 6.55 6.85 8.29 7.93 4.38

95 92.19-92.24 7.97 6.85 6.25 7.84 8.59 -9.60

96 92.24-92.29 8.32 5.60 6.20 7.45 6.73 9.68

97 92.29-92.34 7.42 5.00 5.55 7.48 6.74 9.91

98 92.34-92.39 8.29 5.20 5.50 6.63 6.27 5.45

99 92.39-92.44 6.42 3.80 3.60 5.61 5.92 -5.56

153

Table 18. Weight of flakes, burned rock, and other material separated from the gravel fraction of each sample.

BSS #

Avg. Depth Flakes

Burned Rock Bone

BSS #

Avg. Depth Flakes

Burned Rock Bone

(m) (g) (g) (g)

(m) (g) (g) (g)

1 92.125 4.23 0.01 39 93.925 1.27 43.47

2 92.175 0.94 40 93.975 8.38

3 92.225 0.11 41 94.025 2.56

4 92.275 0.01 42 94.075 10.1

5 92.275 0.31 43 94.125 0.7

6 92.325 0.09 44 94.175 5.43

7 92.375 0.08 45 94.225 0.93

8 92.425 0.32 46 94.275 3.49

9 92.475 14.36 47 94.325 1.38

10 92.525 0.19 48 94.375 1.26

11 92.575 0.1 49 94.425 3.88

12 92.625 0.11 50 94.475 2.45

13 92.675 0.16 51 94.525 1.37

14 92.725 0.13 52 94.575 2.61 0.01

15 92.775 0.13 53 94.625 3.86

16 92.825 1.18 54 94.675 4.48 0.01

17 92.825 0.17 55 94.725 1.54

18 92.875 0.03 56 94.775 0.6

19 92.925 0.12 57 94.85 1.85

20 92.975 0.24

21 93.025 1.36

22 93.075 0.15

23 93.125 1.91

24 93.175 1.78

25 93.225 2

26 93.275 5.96

27 93.325 4.6

28 93.375 2.4

29 93.425 2.4

30 93.475 0.45

31 93.525 2.77

32 93.575 5.16

33 93.625 1.69

34 93.675 0.16 91.52

35 93.725 0.7

36 93.775 6.8

37 93.825 4.23 161.31

38 93.875 1.06 225.53

154


19.0

BSS #

Avg. Depth Flakes

Burned Rock Preform

BSS #

Avg. Depth Flakes

Burned Rock Preform

(m) (g) (g) (g)

(m) (g) (g) (g)

67 94.425 17.02 156.32 61 94.675 44.91 156.32

66 94.475 14.48 62 94.725 14.78

58 94.525 9.96 88.07 38.33 63 94.775 15.01 88.07

59 94.575 14.44 117.27 64 94.825 16.74 117.27

60 94.625 38.65 156.32 65 94.875 16.44


BSS #

Avg. Depth Flakes

BSS #

Avg. Depth Flakes

(m) (g)

(m) (g)

68 92.225 0.57 78 92.725 0.27

69 92.275 0.03 79 92.775 0.13

70 92.325 0.14 80 92.825 0.28

71 92.375 81 92.875 4.8

72 92.425 0.03 82 92.925 0.04

73 92.475 0.07 83 92.975 0.13

74 92.525 0.09 84 93.025 0.09

75 92.575 0.29 85 93.075 0.07

76 92.625 1.61 86 93.125 0.37

77 92.675 5.31


BSS #

Avg. Depth Flakes

BSS #

Avg. Depth Flakes

(m) (g) (m) (g)

93 92.122

5 0.12 97 92.315 0.07

94 92.172

5 0 98 92.365 0.24

95 92.215 0.05 99 92.415 0.01

96 92.265 0.02

155

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VITA

Anastasia Gloria Gilmer was born in Knoxville, Tennessee on February 8th

, 1988

to Maryann and Bill Gilmer. Her family moved to Kingwood, Texas in 1990. She

attended Texas A&M University and graduated in 2010 with a B.S. in Geology and a

minor in Anthropology. In the fall of that year, she enrolled in the Graduate College of

Texas State University-San Marcos in the graduate program in Anthropology.

Permanent Email: [email protected]

This thesis was typed by Anastasia Gilmer.

Documents

GEOARCHAEOLOGICAL INVESTIGATIONS OF SITE FORMATION