AD-A127 252 A PROTON MAGNETOMETER SURVEY OF BORROW AREAS ALONG /CUT-OFF LAKE: L-246(U) NORTHEAST MISSOURI STATE UNIVKIRKSVILLE L GRANTHAM ET AL. MAY 80 DACW41-77-M-1327

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A PROTON MAGNETOMETER SURVEYOF BORROW AREAS ALONGCUT-OFF LAKE: L-246

Prepared by

Larry GranthamResearch Ins tructor

Northeast Missouri State UniversityKirksville, Missouri 63501

and

Earl V. MemryAssistant Professor of Earth ScienceNortheast Missouri State University

Kirksville, Missouri 63501

Conducted for

Kansas City District --TC

Kansas City, Missouri

under i-I

Li P.O. #DACW41-77-M-1327

byNortheast Missouri State University

Kirksville, Missouri 63501

May, 1980 = 188 04 19 186

A PROTON MAGNETOMETER SURVEYOF BORROW AREAS ALONGCUT-OFF LAKE: L-246

Prepared by

Larry GranthamResearch Instructor

Northeast Missouri State UniversityKirksville, Missouri 63501

and

Earl W. McMurryAssistant Professor of Earth ScienceNortheast Missouri State University

Kirksville, Missouri 63501

Conducted for

U.S. Army, Corps of EngineersKansas City DistrictKansas City, Missouri 3

under

P.O. #DACW41-77-M-1327

byNortheast Missouri State University

Kirksville,' iissouri 63501

May, 1980

PREFACE

This magnetometer survey was conducted after acultural resources survey of the area (Cooley andFuller, 1976) revealed the possibility of sunkensteamboats in the area of Stage I construction. Becauseof this, two borrow areas unstipulated and unsurveyedat the time of the cultural resources survey weresurveyed using a GEOMETRICS, digital readout, protonmagnetometer. The project was under the generalsupervision of Dean A. Rosebery, Northeast MissouriState University, Kirksville, Missouri. Field workwas conducted by Larry Grantham and Earl McMurry, bothof Northeast Missouri State University. We wish toexpress our thanks to the Science Division of North-east Missouri State University for both equipment andgeneral support. We also wish to thank the Corps ofEngineers for making this project possible.

A number of people contributed to both the fieldwork and to the analysis, some of whom deserve mentionhere. We would like to express our gratitude to E.Dederick Carrasco and Roger B. Boyd, both of whomcontributed time in the field in order to get theproject completed in the specified time limits. Asit was necessary to change grid pattern size betweenthe initial set up and the field work, additionalpersonnel were necessary.

LDG

ii

TABLE OF CONTENTS

INTRODUCTION .. ...................

Description and Objectives of Research .- 1

Environmental Setting .. ........... 5

SURVEY METHODS AND PROCEDURES

Methods....................8

PREVIOUS INVESTIGATIONS

Archaeology. .. ................ o

History. .. ................. 10

Geomorphology. .. .............. 12ISURVEY RESULTS. .. ...............16

SUMMARY AND CONCLUSIONS .. .......... 21

REFERENCES CITED ................. 22

REVIEWOCOMMENTS.................46

I i llt

LIST OF TABLES

Table 1. L-246. Observed Magnetic Anomalies. 17

LIST OF FIGURES

Figure 1. L-246. Project Area ......... 2

Figure 2. L-246. Borrow Areas, North Shoreof Cut-Off Lake. ...... 3

Figure 3. L-246. Location of Landings onBowling Green Bend, 1876 . 13

Figure 4. L-246. Generalized Model of Erosionand Movement in Meanders .14

Figure 5. L-246. River Movements in BowlingGreen Bend, 1819-1918 . .15

Figure 6. L-246. Proton Magnetometer SurveyBlocks..........27

Figure 7. L-246. Block A .......... 29

Figure 8. L-246. Block B .......... 30

Figure 9. L-246. Block C .......... 31

Figure 10. L-246. Blocks D,E,F,G,H......32

Figure 11l.. L-246. Blocks 1,3.............33

Figure 12. l246--- -.3toqks K, L,M, N........34

Figure 13. L-24.6 Bliobks 0,P..........35

Figure 14- L-2 4A.- kldcks Q,R,S........36

Figure 15. L-246. Blocks T,U,V,W.......37

Figure 16, L:1"246. 'Blocks X,Y,Z,AA ....... 38

Figure 7.L-246. Blocks AB,AC,AD,AE.......39

Figure 18. L-246. Blocks' AF,AG,AH,AI. ..... 40

LIST OF FIGURES (Continued)

Figure 19. L-246. Blocks AJ,AK,AL,AM,AN . , 41

Figure 20. L-246. Blocks AOAP,AQ,AR . . . . 42

Figure 21. L-246. Blocks AO,AP,AQ,AR, andLocation of Anomaly Areas. 43

Figure 22. L-246. Anomaly grid values at 5-foot intervals with 100gamma contour intervals . 44

Figure 23. L-246. Visual representation ofanomaly areas, viewerfacing east .•.. . .. 45

Figure 24. L-246. Visual representation ofanomaly areas, viewerfacing south .. .... 46

iv

ABSTRACT

A proton magnetometer survey of borrow areasalong the north shore of Cut-Off Lake was performedusing a GEOMETRICS proton precession magnetometer.The area was surveyed using a twenty-feet grid spacingwith five-feet grid spacings in areas of interest.Magnetic anomalies were discovered, but most of thesewere associated with modern artifacts at the surface.Two anomalies at the eastern end of the borrow areaswere investigated in greater detail with a gridspacing of five feet. The objects causing theseanomalies are fairly shallow and are probably notvery large. It appears highly improbable, based onhistorical and geomorphological evidence, that thearea could contain evidence of buried steamboats. Theobserved anomalies lie above the level of the river,and it appears that these could not be part of buriedsteamboats. The anomalies lie on the bank of adredged drainage channel and are buried under thespoil pile. It would appear that these anomalies areassociated with the dredging of this drainage channel.

/

V

INTRODUCTION

Description and Objectives of Research

The L-246 levee unit consists of portions of theMissouri River floodplain from Brunswick, Missouri onthe Grand River, eastward to the entrance of the newchannel of the Chariton River with the Missouri Riversouth of Dalton, Missouri. The Stage I constructionconsists of levee units on both sides of Palmer Creekfrom the Norfolk Western Railroad to Cut-Off Lake, thewestern and portions of the eastern edges of Cut-OffLake, and both sides of Palmer Creek from Cut-Off Laketo Bushwhacker Bend on the present Missouri River (seeFigure 1).

In June of 1977, Northeast Missouri State Universityentered into an agreement with the Corps of Engineers,Kansas City District (P.O. #DACW41-77-M-1327) to conducta proton magnetometer survey of borrow areas along thenorthern shore of Cut-Off Lake. These borrow areas weresituated between the proposed alignment of the northernlake closure levee and the northern shore of the lake(Figure 2). The rationale behind this survey was thefact that the cultural resources survey (Cooley andFuller 1976) had indicated that several steamboat wreckshad occurred in the construction areas. Two wrecks hadoccurred in the immediate vicinity of Cut-Off Lake. Thenorthern shore was believed to be a potentially sensi-tive area for the location of same.

The value of the remains of steamboat wrecks asimportant cultural resources has already been demon-strated (c.f. Petsche 1974, Switzer 1974). As Petsche(1974:2) has pointed out, the historical significanceof the cargo may be considered as material culturecaptured in time, precisely dated, and representativeof the mining technology and frontier economy of mid-19th century North America. The importance of theselies not only in the extreme amounts of data availablefrom the cargo, but the fact that they result from acatastrophic incident with instant preservation ofsignificant archaeological evidence. The cargo andthe ship itself are responsible for not only fillingout our view of life in the west and gold mining, butalso the active system of trade and river boat lifewhich dominated the means of transportation to the westduring that period (Petsche 1974:2).

U.S. 24

+4

+ +

+

++

+ 0

Figure 1. L-24b. rruJcs-s- trea

344,000 E 346,000 E

z00

NkkN

CS

CIO,

In,

400

0EE

348,000 E

z0

P~l.L12 I 0

1 .290,000N 34S,O00E 350,000 E

0 400 G00

FEET

Figure 2. L-246. Borrow Areas, North Shore ofCut-Off Lake

Our objectives for this project were threefold.Our primary objective was to locate discerniblemagnetic anomalies in the borrow areas. The secondobjective was to discern whether anomalies encounteredwere steamboat wrecks or not through both analysis offield data and through literature research. Ourthird objective was more methodological in that wewished to expand the range of anyone's ability toidentify steamboat wrecks, should one be located. Todate, the Bertrand is our only example of a steamboatwreck located by magnetometer survey, and the Bertrandwas loaded with a considerable quantity of ferromagne-tic material. This is not true of all steamboats,particularly if the machinery was salvaged.

In attempting to determine what we would considerto be a pattern indicative of steamboat wrecks, wehad very little background. To date, the Bertrandhas been the only example of a steamboat wreck locatedby magnetometer survey. The Bertrand was bound forMontana Territory loaded with freight when it sank.We had little reason to expect that either of the twoships which sank in Bowling Green Bend were as heavilyloaded. One was returning from Omaha, and the loss onthe freight reported as $5,000. The George C. Wolfalso was probably carrying little freight as the totalloss claimed on the vessel was low. Thus, we did notanticipate a pattern completely similar to that of theBertrand. The magnetometer survey of the area ofthe Bertrand indicated that low variation in total gammnavalues, even over the area of the wreck, were no.uncommon. The total variation encountered from t'tegreatest minimum to the surrounding field strength wasless than 100 gamma. However, the area involved inthe anomaly was greater than the total area of the ship.While we did not expect a large anomaly in total gamma,we did expect an anomaly indicative of a steamboatwreck to possess a fairly sizeable areal extent. Thus,we did expect an anomaly with the areal characteristicsof the Bertrand (Petsche 1974) but did not necessarilyexpect similar values in total gamma differences.

Environmental Setting

The Missouri River, which flows just south of theproject area drains most of the Northern Plains, andCut-Off Lake and the entire project area lie withinQuaternary alluvium deposited from the river. Theproject area lies between the confluence of the Grand

and C'a:riton Rivers with the Missouri River. Theseformer two rivers drain most of northern Missouri andsouthern Iowa. Branson (1944:357) described the Mis-souri River plain as ranging from three to ten mileswide with the widest part from about 40 to 70 mileseast of Kansas City. The river cuts in shales in thisregion and where it encountered Mississippian limestoneon the boundary of Howard and Saline Counties, thevalley narrow to about one-third of its upstream width.In the wide part of the valley it has the character-istics of late maturity but in the narrow part it isnot at full maturity. This entrenched feature in theLower Missouri Valley begins just east of the projectarea. The Missouri River occupies a relatively broadvalley in the project area with moderate to well-defined valley definition. The valley is moderatelyto sharply incised into glacial till and loess as wellas the underlying Pennsylvanian deposits. The valleyof the Missouri River averages approximately 70-100feet below the level of the uneroded remnants of theoriginal level plain. Topography is level in the bottom-lands to gently rolling in the uplands to the north.Drainage systems to the north of the project area inthe uplands contain numerous and widely branchingsecondaries. Drainage patterns in the bottomlandslack the feature of branching secondaries. Theaverage fall of the Missouri River in the projectarea is very slow, averaging less than two feet permile.

The geology of the area is largely Quaternarygeology. Nebraskan and Kansan till blanket the area,but depths are not great as compared with areas tothe north. Glacial dri ft is covered by loessial depositsas great as ninety feet near the Missouri Rivervalley. Both of these deposits are highly variable inthickness due to post depositional erosiorn. Bedrockexposures are not common but consist largely of Penn-sylvanian deposits. These deposits consist of cyclicalformations of sandstone, limestone, shales, coal, andclay. Mississippian age formations containing chertylimestones are located to both the east, west, andsouth of the project area. Alluvial deposits of sandand gravel are common in the valley, but silk- and clay-sized particles constitutes the bulk of the alluvialdeposits within the project area. Sand is common onlyalong the northern and eastern shores of the lake.

Soils of the area belong to the Leta, Gilliam,Waldron, Sarpy, Carr, Haynie, and Orrick soil series

6

(Scrivner and Decker 1967). These are calcareoussoils indicating recent deposition-l history. Soilsare defined by texture, and bottom.ind soil texturesare derived mainly from their relative position inrelation to water levels. Thus, soils with finertextures are deposited more slowly and are generallyderived from lower relative positions.

Early Euro-American vegetation is illustrated byCooley and Fuller (1976:Figure 5). Most of the bottom-lands were forested except for areas where standingwater or extremely wet conditions favored grasses.Most of the area to the north of Cut-Off Lake was inprairie at the time of the Government Land OfficeSurveys (GLO, 1816-1819). Upland prairie flora includessuch grasses as big bluestem, Indian grass, wild rye,June grass, dropseed, switch grass, and side-oatsgrama (Kucera 1961). Upland forests included whiteoak, black oak, post oak, elm, walnut, hackberry,hickory, and maple (Grantham 1977). Bottomland forestsincluded burr oak, cottonwood, elm, hackberry, hazel,hickory, lynn, pawpaw, red bud, walnut, and white oak(Cooley and Fuller 1976:32).

Prairie fauna included bison, elk, pronghornantelope, black-tail rabbit, thirteen-lined groundsquirrel, pocket gopher, coyote, badger, and thespotted skunk (Schwartz and Schwartz 1969). Faunamore common to the forested bottomlands includeoppossum, woodchuck, red fox, striped skunk, white-tail deer, beaver, river otter, eastern fox squirrel,Franklin's ground squirrel, and eastern cottontailrabbit (Schwartz and Schwartz 1959).

7

SURVEY METHODS AND PROCEDURES

Field research was conducted during May of 1977.The methodology utilized, as outlined below, wasdesigned largely to be a systematic survey of theborrow areas along the north shore of Cut-Off Lakefor magnetic anomalies of sufficient magnitude toindicate the presence of buried steamboats. Thissurvey was recommended based on the possible presenceof buried steamboats indicated by the initial culturalresources survey (Cooley and Fuller 1976) and inconsultation with other agencies. This survey was donein order to facilitate construction of the project. Thus,if project alternatives or mitigation actions werenecessary based on adverse effects to significantcultural resources, these could be implemented asquickly as possible. The purpose was to provide anintensive survey of these borrow areas in order toprovide an evaluatory mechanism prior to the actualconstruction. The project was designed to be intensive(i.e. as opposed to extensive). This was necessarybased on the limitations placed by the Corps of Engine-ers on the area to be surveyed, and the area to beaffected by actual land modification.

Methods

The use of magnetometers to search for objectsor structures whose magnetic properties contrast withthose of their surroundings is widely used in geo-physics and archaeology. Aitken (1961) described theprinciples of operation of a proton processionmagnetometer and how it is used in archaeologicalapplications.

For this survey, a Geometrics G816 proton preces-sion magnetometer was utilized. This instrument iscapable of resolving differences in magnetic fieldstrength of one gammna (10-5 gauss). The sensing bottledetector was supported on top of an eight foot monopod.This was high enough to avoid the magnetic effects ofsmall metallic objects lying on the ground. Over 1750observations were systematically taken on grid pointsspaced twenty feet apart for the main survey and fivefeet apart in more detailed studies of areas of specialinterest.

8

A map of the survey area appears in Figure 6.A twenty foot grid spacing was selected in order tosurvey all borrow areas in three days. It was believedthat this spacing was more than sufficiently -ilghtenough that a buried steamboat with the same magneticcharacteristics as those shown by the Bertrand (Petsche1974) could be detected. However, we did not have anyguarantee at the outset of the project that any buriedsteamboats in the area would be magnetically similarto the Bertrand.

The topography consisted largely of flat farmfields which were under cultivation at the time ofthe survey. The entire borrow area was surveyedexcept for a small area to the south and east ofFigures 7, 8 and 9. This area was so overgrown thatestablishment of any grid pattern was impossible.Excludi.ng the area of the small relict stream channelwhich runs through this area, less than one percentof the borrow area was not surveyed.

The region to be surveyed was divided into squareblocks 100 feet on a side. A transit was initiallyutilized, but it was quickly discovered that shootingin the squares required a considerably greater amountof time than did the actual survey of the blocks. Thetransit was then utilized to shoot in the northernedge of the blocks and the remainder of the blockswere laid out using tapes. Stakes were used as markersat twenty foot intervals along the edges of the squares.Using these stakes as guides, the twenty foot gridpoints on the interior of the squares were then foundby pacing and using the markers as general guides.Up to four, 100 foot blocks were laid out at one time.The magnetic field strengths were measured at twentyfoot intervals for the entire area designated beforelaying out a new block area. The measurement of fourof these 100 foot blocks involved 126 observationpoints and could be completed in about twenty-fiveminutes by a three man team. In all cases, the estab-lishment of the grid system required more time thanthe completion of the measurement of the points.

Temporal changes in the magnetic field wereobserved. However, these were so small (generallyless than 2 x 10-6 gauss/mmn) over the time requiredto survey from one to four 100 feet blocks that itwas unnecessary to correct the readings taken back tobase station values. Thus, the contour lines in Figures7 through 22 reflect the magnetic structure of the arearepresented in the figure alone.

9

PREVIOUS INVESTIGATIONS

Archaeology

Archaeological research in the Grand and Charitonriverine systems has been somewhat meager. Most ofthe work conducted to date has centered in the upperreaches of the river systems within reservoir projects(e.g. Shields 1966a, 1966b, Potter 1970, Graham 1977,Grantham 1977, Wheeler 1949, 1959, McKusick and Ries1962, Hoffman 1966, Weichman 1976a, 1976b, Vehik 1971,and Chomko and Griffin 1975). The only archaeologicalprojects in the Big Bend area centered on Hopewell andOneota sites (Bray 1961, 1963, Chapman 1959, Henning1970, Kay 1975, Leaf 1972, and McKinney 1954). Theonly projects conducted within the project area wereassociated with levee unit construction (Cole, Kaplan,Mori, and Wireman 1966 and Cooley and Fuller 1976).

The first of these two surveys in the projectarea (Cole, Kaplan, Mori, and Wireman 1966) recordedfive archaeological sites along the Chariton Riverlevee unit. Cooley and Fuller (1976) recorded fivearchaeological sites, two historic archaeologicalsites, and one historic architectural site in StageI construction of Missouri River levee unit L-246.

History

Historical resources of the project area appearto be well covered by Cooley and Fuller. However,several additional coments on the potential historicalresources of the area appear to be appropriate. Thissurvey was initially prompted by Cooley and Fuller's(1976) notation that several steamboats had sunk inthe area, and it was believed that the north shore ofCut-Off Lake was an area potentially sensitive to thediscovery of these.

In order to find out more about the nature ofthe steamboats which had gone down in this bend ofthe river, McDonald (1926) was examined as a startingpoint. Two steamboat wrecks were known to have occurredin Bowling Green Bend (now Cut-Off Lake). These werethe Waverly and the George C. Wolf. Both of thesewere fairly large steamboats.

10

The Waverly was the smaller of the two. It wasa side-wheel steamboat, unlike the stern-wheel Bertrand.Its tonnage was rated as 452 tons, almost twice thatof the Bertrand. Her length was 200 feet and beam was34 feet. She was built at St. Louis, Missouri in 1666.She had two engines (17" x 5'), two boilers (22' x 44"),and allowed a working pressure of 131 pounds. Shewas owned by John P. Keiser, Thomas Raigan, and ThomasW. Rhea. The master was Captain Thomas W. Rhea. Shestruck a snag and sank in Bowling Green Bend on November24, 1867, while en route from Omaha, Nebraska to St.Louis. The machinery was salvaged, but no apparentattempt was made to salvage anything else. The losson the steamer was reported as $45,000 and $5,000 onthe cargo. The nature of the cargo could not bedetermined. The steamer was part of the Fort Bentontrade and made its first trip to Fort Benton, MontanaTerritory, in 1866, netting $50,000 in its first trip.

Considerably less is known about the George C.Wolf. She was a stern-wheel steamer, like the Bertrand,but her tonnage was rated as 533 tons (over twice thesize of the Bertrand). Captain W. Crapster was shipmaster. She was sunk by a snag in Bowling Green Bendat Babler's wood yard on May 2, 1874. She was listedas a total loss, and the loss reported as $40,000.

Locating general areas where these steamboats wentdown proved to be impossible. However, several generali-zations based on the pattern of river movement andcommercialization on the river are possible. Bothsteamboats were sunk by snags. Snags tend to accumu-late in areas where the river velocity has decreased.The river's velocity is lowest on the interiors ofmeanders and toward the edges on straight stretches.However, these are generally away from the main channel,and the incidence of snags in the main channel (althoughlower than away from it) claimed most of the steamboatvictims. Thus, throughout most of Bowling Green bend,the main channel would be towards the outside of thebend.

No specific location was identified for Babler'swood yard. However, commercial ventures tended tobe located where the channel velocity was not fast butwhere the channel approached the exterior banks (Figure3). Thus, the location of both Nil Landing and Keytes-ville Landing are just prior to and just following thefastest velocity of the bend respectively. Thus, wemight expect the George C. Wolf to have gone down near

one of the landings. As Nil Landing appears to havebeen somewhat newer and more short-lived in nature, itwould appear more likely that this steamboat went downnear Keytesville Landing. If this is true, then thepossible wreck noted by Cooley and Fuller (1976:63)from a local informant may represent the George C. Wolf.

Geomorphology

Several statements about the geomorphology ofriver meanders seem appropriate as this juncture.Sparks (1960:96) explaining the motion of a stream inmeanders. The area of the deepest water in a meanderingstream does not follow the median line of the stream butis deflected towards the concave banks and away fromthe convex banks. The tendency for a stream to continueto flow in a straight line results in a slight increasein the height of the surface on the outsides of thebends. This phenomenon results in a cross-channelmovement being given to the stream . I t appears to bestarted at the bottom layers, as these are flowingless rapidly than the upper layers and are more easilydisplaced. The flow across the bottom from the concavebank to the convex one is augmented by a return flowin the other direction on the surface. This motionis not at right angles to the current but possesses adownstream vector varying with the velocity of thestream. The result is a corkscrew motion which shouldtend to move material from the concave bank to theconvex bank, assisting in the erosion of the outsideand deposition on the inside of bends (Sparks 1960:96-97). Thus, erosion is greatest on the three concaveedges of the bend (Figure 4). There is a limit to thewidth of the meanders, depending on the size of thestream, a larger stream producing larger meanders.This limit on the width is probably caused by two mainfactors. As erosion occurs more rapidly on the threeconcave edges of the bend as the meander becomes largerthe tendency is for the meander to break through intothe next meander with the formation of a cut-off.Secondly, as meandering increases the length of a stream,it reduces its gradient and decreased its energy.The stream then ceases to be so effective an erodingagent (Sparks 1960:13-14).

All of these factors are ampl demonstrated byBowling Green Bend from 1819 to 1876 (Figure 5). Thus,the borrow areas along the north shore of Cut-Off Lakewere in the most actively eroding areas in the bend

12

up until the date of actual cut-off and fill (1879)The area thus would not appear potentially sensitivefor the recovery of steamboat wrecks. Areas in whichfill sequences on the convex edges of bends had begunwould appear to be much more sensitive to the recoveryof such wrecks. Fill sequences would have begun onthe opposite edge of the bend from our survey.

BOWLING GREEN BEND

1876

LANDING

LELANDNNNL

o i@ 000 3000wo4000 5000

Figure 3. L-246. Location of Landings on Bowling

Green Bend, 1876.

13

LEGEND

SERODING AREAS

ACCUMULATING AREAS

STHREAD OF FASTEST WATER

Figure 4. L-246. Generalized Model of Erosion and

Movement in Meanders

14

BOWLI/NG GREEN BEND AREA

/819-1/918

1876 CHANNEL

Bend, 119-191

19 1CHNE

SURVEY RESULTS

Over 1750 observations were taken within thesurvey area (Figure 6). The raw data obtained ispresented in Figures 7 through 22. The actual fieldstrength (in Gamma = 10-5 gauss) at any grid point isfound by adding the tabulated value to Base Fieldvalue given in the table heading. Block AV is theaverage of all the grid point values and SD is thestandard deviation of a single observation. NO isthe number of data points. "DATA IS" identifies thedata according to the letter identification used asfield book nomenclature. The contour lines are at tengamma intervals. The locations of U.S. Army, Corpsof Engineers metal survey posts are shown as blacksquares on each diagram. These are numbered as theywere on the survey posts in the field, so that thelocation of any grid point may be located absolutelywith respect to physical reference points and withrespect to magnetic north. The location of surfacefeatures responsible for some of the magnetic anomaliesseen in the figures is also given in each figure whereappropriate.

An examination of Figures 7 through 20 reveals aregional trend in which the magnetic field increasestoward approximately the southwest with a gradient of13 + 3 gamma/l0O feet toward the south and 9 + 2 gamma!lO0-feet toward the west. This is probably due to themagnetic characteristics of the basement rocks of thearea.

Of more immediate interest is a discussion of themagnetic anomalies observed. In Table I, anomaliesare located with respect to coordinates given in Figures7 through 20. Pairs of numbers refer to a point oneach figure where the first number is the distance infeet north or south of the 0 line and the second numberis the distance in feet from the western edge of theborrow area.

Of all the anomalies in Table I, only those at 60S2540E and 60S 4960E could not be attributed to observedmagnetic objects. The anomaly at 60S 2540E appears tobe attributable to an historic building. Thus theanomaly at 60S 4960E appears to be the only anomaly ofinterest.

In order to study the anomaly at 60S 4960E ingreater detail, the area of the anomaly was gridded

16

TABLE I

OBSERVED MAGNETIC ANOMALIES

Figure Location Comments

7 iON 20E COE Survey markerPIL-9A L146LT

10 0S 675E Trash dumped inabandoned secondarystream channel tothe west

11 100S 1500E Large steel Butler Bin

100S 1620E Trash dumped alongbank, large numberof metal cans

12 80S 1740E Trash dumped alongbank, large numberof metal cans

14 0S 2460E COE Survey markerPC267 + 78.09 L246PC

0s 2520E to OS 2540E COE Survey markerPIL-11A LT BK L246

OS 2580E to OS 2600E COE Survey markerPT 269 + 12.75 UPC

40S 2540E to 80S 2540E Barbed wire andsteel fence postin tree

80S 2560E to 80s 2580E Trash dumped alongbank, large numberof metal cans

15 1005 2600E Trash dumped alongbank, large numberof metal cans

OS 2600E COE Survey markerPT 269 + 12.75 UPC

17

TABLE I (cont'd.)

Figure Location Comments

17 60S 3540E to 80S 3560E Nothing on the surfacenear area where soilcolor and historicmaterial suggests anhistoric building

80S 3640E to 100S 3640E COE Survey markerPIL-12-A

80S 3740E COE Survey markerPT 280 + 52.81 L246 LT

18 20S 4200E COE Survey markerPC 285 + 08.98 L246 LT

80S 4180E to 100S 420oE Large metal object inold channel to the south

19 80S 4200E to 80S 4240E continuation of above

20 0S 4720E COE Survey markerPT 290 + 49.09 L246 LT

OS 4860E COE Survey markerPC 291 + 94.45 L246 LT

20S 4940E to 20S 5000E Small negative anomaly,unexplained

60S 4940E to 60S 5000E Large positive anomaly,unexplained

18

off in a rectangular area, and an additional 175magnetic field determinations were taken with gridintervals of five feet and with the detector bottlelocated approximately four feet above tihe earth'ssurface. This area is illustrated in Figure 21, anOthe location of the two magnetic anomalies with respectto the survey markers is included.

The two magnetic anomalies are located by startingfrom survey marker PC 291 + 94.45. The smaller of thetwo anomalies is located 83 feet magnetic east and 67feet magnetic south from the marker. The largeranomaly is located 120 feet magnetic east and 101 feetmagnetic south of the marker.

The actual values found for the earth's magneticfield strength are given in Figure 21. The conventionsused as titling information are the same as those usedin Figures 7 through 20. A contour map with a contourinterval of 100 gamma is superimposed on these valuesin Figure 21.

In order to illustrate these anomalies in greaterdetail, an attempt at a three dimensional representa-tion of them appears in Figures 23 and 24. In Figure23, the anomaly area is viewed from the west (viewerfacing approximately magnetic east). All profilesare drawn to the same scale but have been offsetvertically for clarity.

The data shown in Figures 20, 21, and 22 may beused to estimate the depth of burial of the objectsresponsible for its anomalies (Dobrin 1960:311).Since the precise "magnetic geometry" of the buriedobjects is unknown, it is impossible to predictexactly their depths of burial. However, applicationof standard "half-width" rules suggests that the largeranomaly is associated with an object(s) lying fromabout three to twelve feet below the surface, withthe smaller anomaly produced by an object(s) lyingfrom about one to five feet below the surface.

Both of these objects lie on the left bank of adrainage channel which enters from the north acrossan old terrace, crosses the old Palmer Creek channel,and enters into the northern bank of Cut-Off Lake.The bank in which the objects are buried is coveredby a large spoil pile. As we did not reasonablyexpect a higi, potential for steamboat wrecks in the

19

area and as both objects lie well above the levelof the river, we expected that both objects wereassociated with the dredging of the drainage channel.The drainage channel appears to have been constructedin the late 1930's (Elmore 1977). As the channelends at the bank of Cut-Off and these objects areapparently under the spoil pile, it is likely thatthese objects are associated with the constructionof the drainage channel.

20

SUMMARY AND CONCLUSIONS

Time limits imposed by the Corps of Eneineer.on the field work aspect of this study dictatec t.u:the borrow areas along the north shore of MissouriRiver Levee Unit L-246 be surveyed at grid pointspacings of twenty feet. This would be sufficientlysmall grid spacing to detect deeply buried objects whosemagnetic qualities is reasonably strong. However,other objects of archaeological interest of smallerdimensions or lying nearer the surface may have beenmissed.

Magnetic anomalies were found by the study. Thosewhich were not marked by observable surface featureswere marked by wooden lath markers with appropriatelocational information. Most of these were associatedwith modern artifacts observed at the surface. Specialattention was focused on two fairly large magneticanomalies which were investigated in detail be a fivefoot grid spacing. The objects causing these anomaliesare fairly shallow and are probably not very large.

It appears improbable, based on historical and

geomorphological evidence, that the area could containevidence of buried steamboats. The observed anomalieslikewise appear to be above the level of the oldchannel. The anomalies lie on the bank of a drainagechannel, and it appears that these anomalies are associ-ated with the materials from the dredging of the drainagechannel. It does not appear that any additional workrelative to the magnetometer survey results is necessary.All of the anomalies noted are attributable to phenomenawhich do not appear to be related to historically signi-ficant events. It is suggested that the area ofthe project be allowed to proceed to the development level.

21

21

REFERENCES CITED

Aitken, M. J.

1961 Physics and Archeology. IntersciencePublisTherFs, Inc. New-York, New York.

Branson, E. B.

1944 The Geology of Missouri. The Universityof-Missouri 9-tudies, Vol. 19, No. 3. TheUniversity of Missouri Press. Columbia,Missouri

Bray, R. T.

1961 The Missouri Indian Tribe in Archaeologyand History. Missouri Historical Review,Vol. 55, No. 3.

1963 Southern Cult Motifs from the Utz OneotaSite, Saline County, Missouri. The Mis-souri Archaeologist, Vol. 25.

Chapman, C. H.

1959 The Little Osage and Missouri IndianVillage Site, ca. 1727-1777 A.D. TheMissouri Archaeologist, Vol. 21. -g. 1.

Chomko, S. A., and D. E. Griffin

1975 An Archaeological Survey of the ProposedMercer Reservoir, Missouri-Iowa: 1973.Unpublished manuscript. Report to theNational Park Service. Lincoln, Nebraska.

Cole, K. W., D. H. Kaplan, J. L. Mori, and M. S. Wireman

1966 An Archaeological Survey of Three MissouriRiver Levee Projects in NorthwesternMissouri. Unpublished manuscript. Reportto the National Park Service. Lincoln,Nebraska.

22

Cooley, R. E., and M. Fuller

1976 An Archaeological and Historical Surveyof Areas to be Affected by the Constructionof the Missouri River L-246 Levee,Chariton County, Missouri:1976. Unpub-lished manuscript. Report to the U. S.Army Corps of Engineers, Kansas CityDistrict.

Dobrin, M. B.

1960 Introduction to Geophysical Prospecting.McGraw-Hill o-okCo. ew York, New York.

Elmore, J.

1977 Personal communication. Project engineer.

Graham, J. B.

1977 An Archaeological Survey in the ProposedLong Branch Reservoir, Missouri:1972.Unpublished manuscript. Report to theNational Park Service. Lincoln, Nebraska.

Grantham, L. D.

1977 Long Branch Lake Archaeological Resources,Volume One: Ecology, the Survey, Analysis,and Recommendations. Unpublished manu-script. Report to the U. S. Army, Corpsof Engineers, Kansas City District.

Henning, D. R.

1970 Development and Inter-relationships ofOneota Culture in the Lower Missouri RiverValley. The Missouri Archaeologist, No. 32.

Hoffman, J. J.

1966 An Appraisal of the Archeological Resourceso the Rathbun Reservoir, Iowa. Prepared--y t River Basin Surveys, SmithsonianInstitute. Lincoln, Nebraska.

23

Kay, M.

1975 Central Missouri Hopewell Subsistence-Settlement System. Unpublished Ph.D.dissertation. University of Colorado.Boulder, Colorado.

Kucera, C. L.

1961 The Grasses of Missouri. University ofRfssouri StuaTeTs, Vol.34, No. 2.University of Missouri Press. Columbia,Missouri

Leaf, G. R.

1972 The Function of the Old Fort in CentralMissouri Oneota Subsistence and SettlementSystems. Unpublished M. A. Thesis. Uni-versity of Missouri. Columbia, Missouri.

McDonald, W. J.

1926 The Missouri River and its Victims: VesselsWrecked from the Beginning of Navigationto 1925. Missouri Historical Review,Vol. 21.

McKinney, J. J.1954 Hopewell Sites in the Big Bend Area of

Central Missouri. The Missouri Archaeo-logist. Vol. 16, No71.

McKusick, M., and J. Ries

1962 Archaeological Resources of the RathbunReservoir Drainage, Iowa. SEte University

Petsche, J. E.

1974 The Steamboat Bertrand. Publications inAr-heology, NoTII. National Park Service,Department of the Interior. Washington,D. C.

24

Potter, S. R.

1970 An Archaeological Reconnaissance of theProposed Long Branch Reservoir, Missouri:1969. Unpublished manuscript. Report tothe National Park Service. Lincoln,Nebraska.

Schwartz, C. W. and E. R. Schwartz

1959 The Wild Mammals of Missouri. Universityo-M- the Missouri Conser-vation Commission. Columbia and JeffersonCity, Missouri.

Scrivner, C. L. and W. L. Decker

1967 The Availability of Subsurface Water in_-_ssouri for Consumptive Use by- ants.Water Reso-urces Researc enter. UiiT-ver-sity of Missouri. Columbia, Missouri.

Shields, W. F.

1966a Archaeological Investigations in the ThomasHill Reservoir, North Central Missouri:The 1965 Field Season. Unpublished manu-script. Report to the National Park Service.Lincoln, Nebraska.

1966b An Archaeological Investigation of theChariton River Drainage in MissouriUnpublished M. A. Thesis. University ofMissouri. Columbia, Missouri

Sparks, B. W.

1960 Geomorpholo Longmans, Green and Co.London, Engand.

Switzer, R. R.

1974 The Bertrand Bottles: A Study of 19th-eitury GlassaTn-- ramc- Cnial-ers.-ITMtlon-sin--ArrcheologyNTo. 12.

National Park Service, U. S. Department ofthe Interior. Washington, D. C.

25

United States Department of Agriculture

1941 Climate and Man. U. S. Department ofAgriculture. U. S. Government PrintingOffice. Washington, D. C.

Vehik, R.

1971 An Archeological Survey of the ProposedPattonsburg Reservoir, Missouri:1969.Unpublished manuscript. Report to theNational Park Service. Lincoln, Nebraska.

Weichman, M.

1976a A Preliminary Archaeological, Architec-tural and Historical Survey Within theUpper Chariton River Valley: AppanooseCounty, Iowa and Putnam County, Missouri.Unpublished manuscript. Report to theDepartment of the Army, Corps of Engineers,Kansas City District.

1976b An Intensive Survey of Archaeological,Architectural and Historical ResourcesWithin the Proposed Lodge Creek ComplexProject, Lake Rathbun, Iowa. Unpublishedmanuscript. Report to to the Department ofthe Army, Corps of Engineers, Kansas CityDistrict.

Wheeler, R. P.

1949 Preliminary Appraisal of Archeologicalresources of the Rathbun Reservoir, CharitonRiver Basin, Iowa. Unpublished manuscript.River Basin Surveys, Smithsonian Institu-tion. Lincoln, Nebraska.

1959 Archeological Surveys of Three Localitiesin Southern and Southwestern Iowa. Journalof the Iowa Archeological Society, Vol. 8.T_3w~a-ity-i owa.

Wright, H. E.

1968 History of the Prairie Peninsula. Inuaternary of Illinois, R. E. Bergstrom(ed), pp 7-88. University of Illinois,College of Agriculture, Special Publication,No. 14. Urbana, Illinois.

26

C344OOOE 346,OOOE

'.14

Xw w

00.7. ....

0a XA

346, 000 E 1,290

400 0

F

6,000E 340.000 E

115

16a

.............................................................................

1,290.000W 348,000£ 350,000£E

400 0 400 800

FEET

Figure 6. L-246. Proton magnetometer survey blocks.

27

FIGURE 7

BLOCK VALUES X 1: DATA IS A 8

BASE FIELD 37200.0 BLOCK AV 20.2 SD =8.6 NO 8

~~~~~ "348 2 2 92

8 3 2 8 7 39'

Igu9 e L L246LT Bl6 A11 341

,20 7 1 16 529

FIGURE 8

BLOCK VALUES X 1: DATA IS BBASE FIELD = 54200.0 BLOCK AV = 40.3 SD 33.5 NO 115

7

SECONDARY 10 71

10 9

19 13 12

1 13 14 -150' N

26 21 19 16

30 28 24 21 18

33 30 29 27 24 21

33 36 30 28 26 21

35 34 33 3 1 30 25 -50' N

36 38 36 37 36 38

38 39 35 38 4 " 38

39/745 36 4 1 40 4

40 44 39 40, 41 '40

43 35 35 43 43 43 - 50' S46 45 42 47 45 47

47 49 45 52 46 551

49 5 549 5 8 53 51 54

53 53 51 55 54 54

55 56 54 6 -150' S

51 58 56 64 64

61 58 59 70---

64 68

0 E 2I CUT-OFF LAKE100 ' E

20

Figure 8. L-246. Block B

30

FIGURE 9

BLOCK VALUES X I- DATA IS C

BASE FIELD = 57200.0 BLOCK AV = 13.0 SD = 10.2 NO = 53

1 1 -1 -I -1 -1 0

4 3 1 0 1 1

6 4 5 4 5 6

B 7 7 7 8

50' N - 13 11 11 13 14

16 16 16 18 21

20 19 221 2--20 - 3 21 22 23 1

J 300' E

22 21 27 27 IN-FILLED CHANNEL50' S - 24 24 28

28 31

31 31

200' E/

CUT-OFF LAKE

Figure 9. L-246. Block C

31

WU

IDI

LJ-4 ~ h d ~ Lfl Ll -4

a -4

C)'

Io ID ID -. -

0 ; 0 0 '0 IT '0 I

z Ur ID 'o .0 '0 '0 r-

U) C' ) - c U 'ID ' D '0 .0 ' r-

U)

U

U-'-

(4 110 -. ~ .

oD Io r, r" ar0- tfQ . 0 N- N - N

o'- a, -

-4rU - N- ,4 -o -4 .

H- sO r- N- N- N

C' ID r - r> - -D C0 '0 '-.C)

'.4-4 I

U) ID

U) 0' ' ' C -

Fiur 1. L-46 HlcsD,,,

CU) 3-

FIGURE 11

BLOCK VALUES X 1: DATA IS I JBASE FIELD =5700).0 BLOCK AV =88.5 SC 13.6 NO 6

0 U q 98 94 96 92 93 94 90 91\88 89

97 100 q7 97 97 95 9!, 95 92 90 89

96 97 95 96 98 97 95 94 94 92 92

89 2 96 97 94 94 94 93 95 90 Q9

73 82 87 8 9015 8 75 87 93 9j10- S- 1 7 6 2 /1 6 3? 7 87 % +7

1700' E

S 1500' E _'Metal Cans~

P I 258 + :7.17 L246 LT

Butler Bin CUT-OFF LAKE

Figure 11. L-246. Blocks I,J

33

0- In Ca 0-

a- - Cfl

r r - r -r 0 -

cc S 40 0) '

S . 0- 0- 00 0C

II 0- 0--

o CS

r- cc 00 0.

I~ 0- 0- 0-0c

-, - 0- r c0 ccr- 0- C-r 0 - 0

z- 0 c c cc

a'-0-0 - CC cc or,

cc c

Oz 0- 00 0-0 c SU)

<c- 0o 00 0C 00 C

0- CCO c c cc

0- cc c c c

Figure 12. L-246. Blocks K,L,M,N

34

I 'II' " ' ' I I I I i

0z0

LI, VI Lfl LIn '.

U1~ r- 00 -4 -4LI) Ln' LIn '0 .

04C' Lf, a% C4'f(2LIn LI1 L .0 '

*Lf) LIf '0 '. .

(n -0 0 0 - r- '0

001Ii 0 (IN C .0 IN0 IL

t-4 (2'-40 .4 ' -40

Im -

-40 C) . N . NN.

kM 00C4r r :0 U)

Figure 13. L-246. Blocks O,P

35

-4

+

4 rA

0~

z~~ e'j

11

-4 2. ICGL) C.)4C -4 001-4U

aI C(IC

I0 U

.-4 0 ON P4 0II 4 '. O 0 t r 0 0 :

r-.n . go)a'~'.00

-4-4-4 -4 +-4

I It LP) F- C) - .> mm~ r- 4 C4 04 C41-4 1 -4 -I PLO'v-

CO. UIL -1 -4 4 e'j g

<C 0 a' M a' r- 0-H -4 v-4 C'J C'.J h

C) V) 00 C It - o 4>C) ,-I -1 v-4 CJ C'4 1 -1

-4 C

x Ur .-4 v-A C14 e4S C14 04

C/I 00C40_4 r 4" CIS! Cn

> 1-4 a' C4 '.0 a' -4

0Uto 0 M~ ',0 00 C4 z

P4I A " 4 C.0 C-4

C'q CN CNJ 4 C14 m

Figure 14. L-246. Blocks Q,R,S

36

11 ol aj C.)

0 0 W a, CNr- 00

a, C4 -100 00

r- 00 00 00

Li

-'T0 00 00

00

00 00 00 00 a,.

00 -1 cn - (3,m 'o00 00 00 00

00 00 C) 'T- 00 00 a, a,

C, V) C14w w al a,

- T - Irl00 00 cr, a, a, Ol :4

0000 -1

L 11 00 cr 00 C, C), LLU.

-1 Ol C) -i r-

U 00 00 13, ol C, al 0

cn

OC 00 a, a a, c

< C)c Ol CYN a, (31 C-

(71 a, ol (7 C3, 0

U) 11 C31 C a, 0

C14

Lncl, a, a, \ CN

>

cn Lr) 00 J, CY, C,4U w a, C31 Ol C, a, a\

cn

'D Ln CD -4a, a, a, C) a,

C ) 10 r- C14 ola\ m a, (31 M 10

-4

1'T 10 OD 00

a\C4

rA

Figure 15. L-246. TUVW

37

10 a c" 4 0 0 ' -m c' -11 IT 4r -1 V)

M ON C/' 'I 0 '0

In Ln In In 10 0 ' DC'

'0n C1O N ' 0 10 ND

InN - n c-N 7 0 D ND

CZ U) -4 -w7 0 ' '~ 44 n u- ) tn 7 n 7 0 10 '0

(fln 4l 7 177 7 ' 0 r-

If M 7 4 7 0 '0 1 '0 rIL

X0 <0 1

-n 7n V7 70 0 ID 10 r0 c-,l~.

// 00wl N~ 10 0n c-N 4 7

(D 7r 7n '0 0 '0 '0 '0 N-

- 0 , ' - O -

42 m 7N V 0 7 '0 ' '

r- a, 7 r 0 -4 - o C 0 07r 7 0 0 '0 0 - -4

0 7O 10 0 40 '0 '0 0'

0

Coil 7 0 '0 N 0

0000- M

C7 7 D N0 4

'0 '0 '0 N N N

Fiur 16. L-46 NBock XYZ

'0 '0 '0 N N N8

N

CO

CN

-N 'a ) 'a 'a , 7 1 r- 0 E O

"~~~ CNm I 4 M n cI I

N4 10 Do C0 0--0 a1C4 NM

In a0 ~ 'N '

-4"1 0 C14 C-4 n 1 0' n L

M en en en N m It -t

Nn r- O I

rI N 4 N ) 0 0 n 0' ' 0

C'4 a, a,

In) N ) N 0 N , _4 4A 4- 4 N wa

'a D +I 0-4 N3, C/ - r 4 I

a, *0 00 N N) C 4 0 N4 'a 0) 10 LA

CI4 m 4 ~ N 4 4 4 Nr LN Nr N -.

on > O +) 0

C0 4 -4 In el 00.0

'A a, 4D 1.N' rn 0 ) m 410 <r z I U ,

CO 0COB 'a 0 zt 0, M 4 N, 00 mI 4-I

10I 'a 'a a 0' 0 0 N 0V ->n I 0 10 a 1 '

L)LIW 00 r- -4 0 -4 4t 'a m

N~~0 N-4 -

C)C0 N N 10 0 'I -

Figure 17. L-46 Nlck r- N -4,

39N

C4

o 0 H

0 - C-

"44

r-- C) 4

r- cnI' N Q LWC n ' -'A -4

kr-)

C1 4 4 cI r- 00 V

-4,

0) 0' L) - 4 -4 0 r

'0

C Uo4 -4 1. -4* C4 'L)-

I Lf 00 -44 1 -Cy

N- -4 -4 -4

-4 Q14 C

E-44

Cfl -4 ,4 C-4 C4 C

10 '0 0' NI N

4 -4 4 -4 - q C4 N m Y

-4 -4C 4 q 0 0

-4 '-4 "I N1 N CN m ~ 0'

01 10 '0 0 - 4 N '0 0' i'0 V) 1-1 -4 '-4 C- 0N N* " Ny cn

0' '0 CD m 4 0 N 0 0'n '0O o I -4j " N I N N m~ cn

N) N4 r- Ln -4 N' m 0

C14 N- Nn Nn N C". C

'D '0 'D Ifn /m"\ 00 4t 'D ' -N4 NI N' IC'\N C 'n \ C"e. 00

C)'

Figure 18. L-246. Blocks AF,AG,AH,AI

40

0 C0 0 L - 4

0, r- r.

'0) -4) Lr 10

0 0 '- a- 0-

c14 0r c') 0

vi In .1- 0 10 10

Jn r- un .,-Ln- 10 10

CD 4 (n w1ULn '0 10 10

It .1 .4 r, (

z -

Ln- 10 10 1"

c14 U) 0 '0 a, 4 0 .1-4 ~ 'n 0 'D 1z a- CD

1I ' 0 '0 r- -

10 rID 1~0 r,

D' 0 '0 m0 C-. w

-- 4 UD LL-Us C-. -4 O\ -4 -4 4

t--4 ' P 0 C-. r- . 4 I L

'0 ' 0 '- o '

r.. CD)L ' -0 - r) . -4 r- .00 4 o

0

'0 1r- r, U)'- oD -4

r- os aD c*o r-- m~L)],. -4W) -

C- r- U) PQ- c~

D) 00 00 0,U F - 0 ) U ) C

a, -4 I0 r- 6)F-- U) 00 OD U)

U) ~ 044

4 -

05 /12N 44- U) t)U -4

41

C4

0 In -4 , C 4

V)

- 0 0 CW 4 (n (N--

10 0' 14 c'(N4 C4 en C C1

00 C~ -4 C 4 (

(N () C'( (I4 C, 0

0 ~ ( CI 'A C14 C

00 ( N (

o 1 A 0

C:)

C) -IIft0

w 0 > N 0I.

:D en C 0

(n LNC. 04

CO -4

00 C 4 4 Or

(N C14 c.( 4-4 00 ,14«0 +' (

'N jr) C00 W) 4 (N C

En it 00 0

o 4

> -40 4 4 J

4 4 10 000

O ON

00

42

o, oo en M r- 4-

r-. c14 Cn M

c14 (14 en cn

cq W 1) CN r4

oo en

Itj C) cIc cII t 00 0)I a,0 z C

o C4 -4 C4 -zr 'T C0 W

c c(' a,

cc 04 C) c-j (

10 'Dc )

a, r-41v)4 -:

( 14 It' It 4 0 C)II c') c') c') CD-

01

Sc') C') -- -- -- -- -

t-40 -4 -4 01

cc! cc -00 C') 4 4

C) 04 4

X4c V) 4 U . Coo Ur) -4 0 + -o

ccI

r-4-

0o -4 lo -Ur) V) 41)

C') 0 4)4 V1) 41D

CuC

'-4 Uc) V0 C0

C

01

c14

Figure 21. L-246. Blocks AO,AP,AQ,AR, and Location

of Anomaly Areas

43

C-4 04 enci~r

-,i 14 M~ CI) CI)

aa

44

C

W C-4r- 01 r- 1

In Cr , (

144

N

: 44

(n' U~ U', :t-4C) 1

A I C- 4 1- a, 1

-44

700

55

80

45

70

65

60

5

20

4035

30

25i 64050 FE

NOTH0OT

15 ue2.L26 iulrersnaino nmlaraviw0fciges

*00q

00S0

Figure 24. L-246. Visual representation of anomalyareas, viewer facing south

46

REVIEW COMMENTS

A draft version of this cultural resources surveyreport was sent to the following agencies and individualsfor review of the merits and acceptability of the report.The comments which are pertinent to the final report arelisted below together with the authors responses.

Missouri Department of Natural Resources, Division ofParks and Historic Pr-eservation. Cormment T7T naccordance wiThthe Office of Historic Preservation'sGuidelines for Contract Cultural Resource SurveyReport s, a UY-.7 min. topographic map incatingaI7 areas surveyed during this investigation must beincluded in the report. Also it is recommended thatthe location of any unexplained anomalies be clearlyshown on this map.Response: Agreed. Figure has been added.

Comment 2. Page 8, paragraph 2, line 7: "effected"should be "affected".Response: Agreed. Changed accordingly.

Comment 3. Page 15, paragraph 4, lines 3-5: Anomaly#12 is attributed to an historic building. No furtherdiscussion is made about this anomaly. What will bethe impact on this site? What, if any, is the signifi-cance of this historic structure? More discussion andevaluation is needed to clarify this point.Response: This is a somewhat difficult point to dealwith at this juncture. The anomaly is not in the areaof historic scatter but is probably associated with it.The purpose of the study was to provide a protonmagnetometer survey. A detailed description anddiscussion of the historic archaeological site appearsto be aside from the main theme and detracts from thestudy. We have included an addendum to the report toaddress the topic. A more detailed description appearsin the report of monitoring activities.

47

Comment . The report fails to provide the Corps andother ap;ropriate state and federal agencies with anyrecommendations relative to buried historic resourceswithin the project area. Is any further evaluationrecommended? Although implied in the Summary andConclusion section, specific recommendations and/orproject clearance should be given. Also, as we feelthat the present study is not totally conclusive, theOffice of Historic Preservation recommends that in theevent any cultural materials are encountered, workshould cease immediately and our office notified atonce.Response: Agreed. Recommendations and projectclearance have been added. As monitoring was alreadypart of the project, it was not recommended. All ofthese have been amended.

U.S. Department of the Interior, National Park ServiceM--W est rh ioogcl Center. Comment 17-Thereport is generally satisfactory.Response: No comment required.

Comment 2. The twenty foot grid pattern is adeauatefor a survey to detect a buried steamboat with thesame magnetic characteristics as the Bertrand.Response: No comment required.

Comment 3. The depth estimation for the anomaly onFigure 15 may be too conservative.Response: The depth estimates were felt to be adequateif we assume multiple objects are creating the anomaly.As we do not know the precise magnetic geometry, itwas felt that this was a best estimate of the observeddata.

Comment 4. The following topics should be clarified;more descriptive information is needed. The discussionof Petsche's Bertrand study (page 3) should be expanded.The study revealed that a relatively weak anomaly couldbe indicative of a steamboat. The total variationbetween readings directly over the ship and those awayfrom the ship is not much more than 100 gamma and adifference of as little as 20 gamma is not uncommon.From Petsche's documentation, what magnetic values werethen considered to be significant for this study.Response: Agreed. We have substantially expanded thissection in order to give more background data relativeto the previous Bertrand study as well as to discusswhat we considered to be significant values.

48

...... ..... .... . .. . . . . . 1 ....Maw" - --- - - . . .

Comment 5. Spoil from dredging will create a differentpattern than sedimentation material or qeologicfeatures. If topographic information ore ircluddon the magnetic grids (Figures 2-15), differences inrelief may help explain the nature of the anomalies.Response: We believed that the magnetic grid mapswere already sufficiently complex. Topographicinformation appears on Figure la. Al-hough thefigure was somewhat cluttered, we have attempted toresolve this.

Comment 6. Two of the grids, Figures ]0 and 13, showanomalies in the corners. The gamma differences aresimilar to those in Petsche's study. -hat type orsize cans caused the anomalies? Could it have beenpossible to move the metal cans out of the way andresurvey the area to determine if they were the onlycause for the anomalies? Was anv testing done beyondthe gridded areas?Response: The metal cans creating the anomaly inFigure 10 were dumped along the lake edge for approxi-mately 50-60 feet, while the metal object creating theanomaly in Figure 13 was about boiler size but functioncould not be determined. It was not possible to moveany of this material or survey beyond the griddedarea as all of this was in Cut-Off Lake. Figures havebeen modified accordingly.

Comment 7. The area tested in Figure 18 could havebeen extended to the south to show if a monopole or adipole were developing. The anomaly peaks at 1756 andrapidly drops to minus numbers to the north. Thenumbers begin to decrease to the south but the gridstops before we know what is happening. If the numberslevel off creating a monopole, a natural (geologic)feature could be expected. If they decrease at the samerate as on the northern end, a metal object could becreating the anomaly.Response: The grid was stopped at the edge of the lake.It was not possible to extend the grid to the south.The figure has been modified to reflect this.

49