Upload
others
View
4
Download
0
Embed Size (px)
Citation preview
AFV ...... Afton valley fill
ARK ...... Arsenal kame
AVO ...... Apple valley outwash
BFG ...... Bluff gravel (Dakota &
Ramsey Cos.)
BLG ...... Bluff gravel (Carver Co.)
BLO ...... Bloomington outwash
BMO ..... Big Marine outwash
BRI ....... Burns ice contact
BVK ...... Burnsville kame
BVO ...... Burnsville outwash
CGO ..... Cottage Grove outwash
CLS ...... Crystal Lake sand
COO ..... Crow River outwash
(Hennepin Co.)
CRI ....... Credit River ice contact
CRO ..... Cannon River outwash
CSV ...... Castle Rock valley fill
CWO .... Crow River outwash
(Carver Co.)
DEI ....... Des Moines ice contact
(Scott Co.)
DM ....... Des Moines ice contact
(Dakota & Scott Cos.)
DMU ..... Denmark upland gravel
EAK ...... Eagan kame
EPO ..... Eden Prairie outwash
ERO ..... Elk River outwash
FLE ...... Fish Lake esker
GB ........ Grantsburg ice contact
GCT ..... Grey Cloud terrace
GRT ...... Grey Cloud terrace (Carver
& Scott Cos.)
GVO ..... Golden Valley outwash
HAM ..... Hampton moraine
HLG ...... Hillside gravel
LDT ...... Langdon terrace (St. Croix
River)
LEO ...... Lake Elmo outwash
LGT ...... Langdon terrace (Missis-
sippi River)
LVO ...... Lakeville outwash
MHO ..... Mendota Heights outwash
MPF ..... Mississippi floodplain
(Anoka & Hennepin
Cos.)
MPO ..... Minneapolis outwash
MSF ..... Mississippi floodplain
MTK ..... Minnetonka kame
MYO ..... May outwash
NOI ....... North Oaks ice contact
OSK ..... Osseo kame
OSO ..... Osseo outwash
PLI ........ Piersons Lake ice contact
PRI ....... Prior Lake ice contact
RFT ...... Richfield terrace
RHT ...... Richfield terrace (Washing-
ton Co.)
RIV ....... Rich valley train
RSO ..... Rosemount outwash
SCI ....... Sand Creek ice contact
SCO ..... St. Croix outwash
SCV ...... Sand Creek valley fill
SFI ....... San Francisco ice contact
SMT ..... St. Mary's terrace
SPO ..... St. Paul outwash
SUI ....... Superior ice contact
TOK ...... Tower kame
VDG ..... Valley delta gravel
VRO ..... Vermilion River outwash
WFO ..... Waterford outwash
Table 1. Three-Letter Codes for Informally Named Sand and Gravel Deposits
1 0 1 2 3 4 5 MILES
8 KILOMETERS
SCALE 1:100 000
1 0 1 2 3 4 5 6 7
PRIMARY SOURCES OF CONSTRUCTION AGGREGATE IN THE SEVEN-COUNTY METROPOLITAN AREA, MINNESOTACompiled by
Gary N. Meyer and John H. Mossler
1999
MAP OF PRIMARY AGGREGATE SOURCES
AR
EA
OF
OV
ER
LA
P
WIT
H N
OR
TH
SH
EE
T
GIS compilation by T.E. Wahl, G.N. Meyer, and J.H. Mossler
Cartography and graphic design by T.E. Wahl
Base modified from 1990 Census TIGER/Line Files of U.S. Bureau
of the Census; county border files modified from Minnesota
Department of Transportation files; digital base annotation by
Minnesota Geological Survey
Universal Transverse Mercator Projection, grid zone 15
1983 North American Datum
MISCELLANEOUS MAP SERIES
MAP M-102, PLATE 1
Primary Aggregate Sources, South SheetMINNESOTA GEOLOGICAL SURVEYD.L. Southwick, Director
UNIVERSITY OF MINNESOTA SUPPORTED IN PART BY THE MINNESOTA MINERALS DIVERSIFICATION PROGRAM AS ADMINISTERED BY
THE MINERALS COORDINATING COMMITTEE FOR THE MINNESOTA LEGISLATURE
©1999 by the Regents of the University of Minnesota
The University of Minnesota is an equal opportunity educator
and employer
Seven-County Metropolitan Area
AR
EA
OF
OV
ER
LA
P
WIT
H N
OR
TH
SH
EE
T
Lake
LakeWaconia
Lake
Minnetonka LakeHarriet
Prior Lake
Missis s ippi River
Min
neso
ta
Riv
er
Min
neso
ta
Riv
er
M
ississipp
iRive
r
St. Paul
Waconia
Cologne
YoungAmerica
Chaska Shakopee
Jordan
Belle Plaine
Hastings
DAKOTA CO
DA
KO
TA
CO
SC
OT
T C
O
HENNEPIN CO
CARVER CO
CA
RV
ER
CO
SC
OT
TC
O
93°30´93°45´
93°15´
93°00´
92°45´
44°45´44°45´
44°30´44°30´
94°00´
T.113 N.
T.114 N.
T.115 N.
T.112 N.
R.17 W.
R.18 W.
R.16 W.
R.19 W.R.20 W.
T.112 N.
R.21 W.R.22 W.R.23 W.R.24 W.R.25 W.
T.113 N.
T.114 N.
R.26 W.
T.115 N.
T.116 N.
T.28 N.
T.27 N.
T.26 N.
GCT1
RFT4
LGT4
CGO4MPO4
MPO4
CWO4MTK3
RHT4
MPO4
LEO4
CGO4GBI5
MPO4
CWO4
SUI4
SMT1
GBI4GBI4 GBI4 GBI4
SUI4
TOK3
MPO3
MPO4
DEI4TOK3
CGO3
GBI4GBI3
AFV4GBI4
GCT3GBI4 MPO4
DEI4
LDT4
MTK3AFV4
GBI4
GBI4
MPO3
GBI4 GBI4MTK2
GBI3
CGO4
MPO4
GCT3MTK4
MHO4GBI4 GBI4
CGO4
BLO3
MTK4
SUI4
MPO4
MTK3
MPO4
CWO4
LGT4
MTK4
RFT4
MPO4
CWO5 GBI4
BFG4
MHO4
MPO4
LGT3
GCT4
AFV4
SUI4
GBI4RFT4
GBI4 BLO4 MPO4
MTK2
CWO4
BLO4
GBI4MTK3
MPO3
CGO4
SUI4
CWO5
CWO4
LGT4
RFT4CWO5SUI4
MPO4BLO3 GBI4CWO4 RFT4CWO4
BLO3SUI3
MTK4
CGO4
MHO3
LGT4
BLO4CWO4
GBI3CWO4
GBI4
BLO4MHO3
MPO5
SUI4
SUI4
DEI4CWO4
CWO4
BLO4
BLO3
BLO3
DEI4GCT3
BLO4
GBI3BLO4
CWO4
EPO3GBI4
MPO4
CGO4
DEI4 EPO4
SUI4
BLO4EPO2DEI4
BLO4
EPO4
CGO4
BLO3
AFV4
BLO4
EPO4
GCT6
BLO4 BLO3
BLO3
CGO3
GBI4
CWO4 GBI4 SUI4
BLO2
GBI3
SUI3
MPO4
CWO4
MHO8DEI4
SUI4
BLO4
CGO4
CWO4SUI4
BLO4BLO4
AFV4
MHO4
LDT3
BLO4LGT3
GBI3 SUI4
BLO4
EPO2
CWO4BLO4
MPO4
CGO4
CWO4
SUI2
GBI3
CWO4
BLO5
MHO3
CG04
CGO1
SUI4
GBI3AFV4MPO4
BLO4
GBI4
BLO4MPO3
GBI3
MPO3
AFV4
CWO4
GBI4
GBI4
AFV4
LGT3
CGO3
AFV4EPO4AFV8
BFG3
AFV4CGO4
MHO3
CGO5
CWO4
AFV4
GBI4
MPO4
RIV3
AFV4
SUI3
CWO4
EPO4
EPO4
SUI4BLO4 SUI4CWO5
EPO4
CG04
CWO5
SUI4MPO2
CWO5
LGT6
SUI3 AFV4
CWO5
BFG4CWO4
SUI3
SUI4
BVO4CWO4DMU6
AFV4
LGT3CWO5
SUI4
SUI4
DEI4 GBI4
CWO7
CWO4
SUI3DEI4
BVO4
LGT3
SUI4
PLI4
DEI4
GBI4
DEI4
LGT4
EPO4
SUI4
AFV4
GBI3CG04
RHT3
DMU4
AFV4
PLI4
LGT3
GBI4
AFV4SUI3
SUI4
CWO4
DMU6
SUI3GBI3
SUI4GCT2
SUI4
PLI4
SUI4
GCT7
PLI4 EPO4
RHT6
SUI4 SUI4SUI3
PLI4
SUI3
LGT6
GCT8
RHT6
GBI4 SUI4
SUI4
PLI4
DMU4
PLI8
BFG3
DEI4
SUI3
DEI4 LGT3 DMU4PLI4
EPO4
DMU4PLI4
DMU4
PLI4
RIV4
GBI4
PLI4
SUI4LGT3
PLI4PLI4 SUI4 SUI4PLI4
RHT1
LGT3RHT6SUI4
SUI4PLI4
DMU4GBI4GCT4 DMU4
RHT6
CGO4
RFT4
DEI4
CG04
BLG4RIV5
DMU4
SUI4RFT4
BLG4 LGT3
EPO4
SUI4
CWO5PLI4
PLI4
AFV4SUI3 DMU4
SUI3
RHT4
BLG4
LGT4
GBI4PLI4PLI4 BLG4
DMU4
SUI3SUI3
BLG4 SUI3PLI3PLI4
SUI4
PLI4 PLI4PLI4
LGT2
PLI4
PLI4PLI4
PLI4
EAK4
SUI3PLI4
EAK4
LGT5GRT4AFV4
RFT4
SUI4LGT3DEI4
EAK4GCT6
RHT4LGT3
PLI4
GCT3
BFG4
GRT3
LGT4
LGT6
SUI3
GCT3
SUI3
LGT6
AFV4SUI4 DMU4DEI4
SUI4
DEI4
GCT6
GRT4
DMU4SUI4
RIV5SUI3LGT6
AFV4
RHT3
SUI4
DMU4LGT3
DMU4
SUI4
BFG3
GCT3
LGT3
EAK4
EAK4
SUI4GRT4DEI4
SUI3LGT3
GRT3
RHT4DMU4SUI5
BFG4 EAK4
GRT3
LGT6LGT4
LGT4
SUI4SUI4
RHT6
LGT3
RSO3
LGT5
DMU4
BVK4
LGT3
RIV2DEI4
RSO3
BFG3
MSF8
SUI4
SUI4RFT4 BVK4EAK4
GCT3
LGT3
SMT8
BVK3
SUI3
RSO4
BVK3
LGT3
DEI4 GRT3
MSF8
EAK4LGT3RFT3
DMU4
DEI4
SUI4
RSO4
DMI3
LGT4
RFT4
LGT3
BVK2SUI4
DEI4
LGT4
SUI4LGT2
SUI4
LGT6LGT3
SUI4 DMU4LGT4
BVO3
DMU4
LGT5
DEI4
LGT3
BVO3DMI4
LGT4
LGT3
LGT4
DEI4
RSO5
BVO4
CGO4
RSO3
DEI3RFT3
BLG3
GCT3
SUI4
RSO3
SUI5
HAM4
BLG4 DMI4
RFT4
DMI4
HAM3
SUI3
SUI4SUI2
RSO3
DMI4RSO3
RFT4GCT6
RFT4BVK3
BLG3
RFT4
SUI4
RFT4
LGT4
LGT3
BVK4
BVO3
GCT3
DEI4
BVK2RFT3
BVK1
BVK3
BVK3
RFT4
RFT3
HAM4
BVK4 BVK2
HAM3
DEI4 BVK3GRT4 RSO3
GRT4BVK1
BVK3
RFT3
RSO4DEI4 DMI4
DMI4
DMI4
PRI5RIV3
DEI4
DEI4
PRI3MSF4
DEI4HAM3
RFT3
HAM4
DEI4DEI4
AVO3
DEI4
RSO3
SUI4DEI4
PRI5
PRI3RSO3
DMI4SFI4
SMT8
AVO3
GRT4PRI4
VDG8
RSO4
PRI4DEI4
VDG4DMI4
VRO4
GRT4 AVO8
AVO8
AVO4
HAM4
DEI5
SFI4
DEI4 DEI4
HAM4
AVO7
PRI4
PRI3
HAM4PRI4
DMI3DEI4
AVO3
RSO4
HAM3
AVO3
PRI4
RFT4
PRI4
CRI4
VDG3
SFI3
SMT8GRT4
DEI4
LDT4
LDT3
RSO4
GCT3
DEI4
PRI3
RFT3
DMI4
SFI4
PRI4PRI4
GCT6
PRI2
CRI4
PRI3CRI4
RFT4RSO3
GRT8 RSO2SFI4
RSO3
DMI3 HAM3
DMI3
CRI4PRI4
GRT4
SFI3
RSO4SFI4
RSO3
SFI4SFI4 CRI4
GRT2
SFI4
RFT4GCT6
SFI4
VDG4GRT4
CRI4
GCT6
SFI4RSO4
LDT3
CRI4
DMI4 RSO3
LGT4
RSO4
RSO4
RSO4
RSO3
DMI4 GCT3
SFI4
SFI4
RSO5
RSO6HAM3
CSV4
LGT5SFI4
RSO4
CRI4
SFI4SFI4
RSO4
RSO3
SFI4
VRO5
BLG4
CRI4CRI4
LVO3
LVO3 RSO3DMI4DEI2
RSO3
DEI3
DEI2
CRI3
LVO2
DMI4 LVO7
RSO4
RSO4
DMI4RSO4
RSO6
RSO3RSO4
RSO3
CRI4DEI4
RFT3
RSO4
SCV4
RSO3
RSO2
RFT3
RFT4
LVO3LVO2
CSV4
RSO3
LVO3DMI4
DMI3DEI4
LVO8
RFT5 DEI3 RSO4
RSO6
RSO4LDT3
DEI2
RSO4
RFT3DMI4
DMI4SCI4LVO2
LVO3
SCV3
LDT4
LVO2
SCV4
LGT3
LVO3
RSO6
LVO3
DEI4
RSO4
DMI4DMI5
RFT5
CSV4
RFT4
SCI4
RFT3
RFT1
RSO3VRO3LVO4
VRO4LVO4
DMI4HAM3
SCI4
RSO4
DMI4 CSV4
DMI4
CRI4
SCV4 LVO4
SCI2 HAM4
LVO3CSV4
LGT4
SCV4
LVO8
RFT3
CSV4SCI4
LVO8
SCV4
CSV4VRO8LVO3
SCI4
RFT4
CSV4SCV4 DMI4DMI4
SCV4
DMI4
CSV4
SCI4
DMI5
CRI4
RSO4SCV4
CSV4HAM3
SCI4
CRI4
HAM4SCI4HAM4HAM4
DMI4 CSV4
CRI4
LVO3
RFT3
SCI4
RFT3 SCI4
SCV4HAM3HAM2
CSV4CRI4
RFT4
VRO8
DMI3HAM4
DMI4CSV4
CRI4
VRO4
HAM4 HAM4RFT5
SCI4 DMI4
HAM4RFT2
VRO3
HAM3
HAM3
HAM4RSO4
RFT4
SCI4DEI5
HAM4HAM4RSO8HAM4
CSV4DEI4HAM3
VRO4
VRO4
RSO4
HAM3
HAM3VRO2
VRO3
DMI4
DMI4
HAM4
CRI4
DMI4
HAM4
VRO4
RSO4SCI4
RSO4
RSO4CRI4
RSO4
DMI4
SCI4CSV4
HAM4
CRI4
CSV4
CSV4SCI4
VRO3
DEI4 DMI4
CSV4
SCI5SCI4
CSV4
SCI5
CRI4
DMI4VRO4
RSO4
HAM3
CSV4
CSV4
HAM4
HAM4
DMI4
SCI4
HAM4
HAM4 CSV4HAM4SCI5
HAM3
SCI4
VRO4
VRO8
VRO4
SCI4
HAM4
CSV4
HAM4
HAM4 HAM3
SCI4
HAM3
DMI4DEI4
HAM4HAM4
DMI3DEI4
DMI3
DMI4CSV4SCI4
CSV4DMI4SCI4 SCI4
CSV4 HAM4
SCI4
SCI4 VRO3
CSV4
HAM3
DMI4 CSV4SCI4
SCI4
DMI3 HAM4
HAM4DEI4 CSV4
CSV4
DMI4SCI4 DEI4
HAM4CSV4
SCI4 SCI5
SCI4
SCI4SCI4
DMI4SCI4 DMI2SCI4SCI4 HAM4
CRO8
CRO4
HAM4
CRO4
DEI4HAM4
WFO4
CSV4
DMI2DMI4 CSV4DMI5
CSV4
WFO4CSV4
CSV4WFO5 CSV4
CRO4
CRO3
DMI4
WFO8CRO7WFO4 CRO6
CRO4
CRO8
CRO7
CRO3
DMI4
WFO4CRO2
CRO3
CRO8WFO4
DMI4 CRO8CRO4WFO7
WFO4
WFO4
CRO4WFO8 CRO3
WFO4
CSV4
CSV4
CSV4
WFO4
WFO4
CRO8
WFO4CSV4
CSV4
CSV4
CSV6
DMI4
Every reasonable effort has been made to ensure the accuracy of the factual data on which
this map interpretation is based; however, the Minnesota Geological Survey does not war-
rant or guarantee that there are no errors. Users may wish to verify critical information;
sources include both the references listed here and information on file at the offices of the
Minnesota Geological Survey in St. Paul. In addition, effort has been made to ensure that
the interpretation conforms to sound geologic and cartographic principles. No claim is made
that the interpretation shown is rigorously correct, however, and it should not be used to
guide engineering-scale decisions without site-specific verification.
Note: This map depicts deposits of sand, gravel, and dolostone within the Seven-County Metropolitan
Area that occur geologically and are potentially available as sources of construction aggregate. It is
not a depiction of aggregate resources, in that large portions of the mapped deposits do not have
"reasonable prospects for eventual economic extraction"1 because of competing land uses and zoning
restrictions, and thus are excluded from the operational definition of a mineral resource.
1Resources and Reserves Committee, 1999, A guide for reporting exploration information, mineral
resources, and mineral reserves: Littleton, Colo., unpublished report submitted to the Board of
Directors, Society for Mining, Metallurgy and Exploration, 17 p.
HENNEPIN RAMSEY
WASHINGTON
DAKOTA
CARVER
SCOTT
ANOKA
LAKE
FREM
ON
T
CR
OW
N
ELK
RIV
ER
NO
WTH
EN
SAINT
FRAN
CIS
CEDAR
ISAN
TI
TYPO L
AKE
CO
ON
LAKE
BEACH
LIN
WO
OD
FOR
ESTLA
KE
SCAN
DIA
HU
GO
MAR
INE
ON S
AINT
CROIX
CEN
TERVILLE
CIR
CLE
PINES
WH
ITE
BEAR L
AKE
WESTN
EW
BRIG
HTO
N
CO
ON
RAPID
S
MIN
NEAPO
LIS
NO
RTH
ANO
KA
OSSEO
RO
GERS
ST MIC
HAEL
HAM
EL
RO
CKFO
RD
DELA
NO
MO
UN
D
WAT
ERTO
WN
MAY
ER
WIN
STED
NO
RW
OO
D
PLATO
GR
EEN IS
LE
HAM
BUR
G
WAC
ON
IA
VICTO
RIA
BELLE
PLAIN
E
NO
RTH JO
RD
ANW
EST
BELL
E
PLA
INE
SO
UTH
UNIO
N H
ILL
HEN
DER
SON
EXCELS
IOR
HO
PKINS
SHAKO
PEE
EDEN
PRAIR
IEM
INN
EAPOLI
S
SOU
TH
BLOO
MIN
GTO
N
ST PAU
LW
EST
ST PAU
LSW
WH
ITE
BEAR L
AKE
EAST STILLW
ATER
LAKE E
LMO
HU
DSO
N
SOM
ERSET
SOU
TH
SOM
ERSET
NO
RTH
OSC
EOLA
PRESC
OTT
ST PAU
L
PAR
K
HASTIN
GS
VERM
ILLI
ON
ST PAU
LEAST
INVER
GR
OVE
HEIG
HTS
CO
ATES
FARM
ING
TON
OR
CH
ARD
LAKE
NEW
MAR
KET
CASTLE
RO
CK
RAN
DO
LPH
CAN
NO
NFA
LLS
NO
RTH
FIELD
DEN
NIS
ON
LITTLE
CH
ICAG
O
JOR
DAN
EAST
PRIO
R L
AKE
VESELI
NEW
PRAG
UE
DIA
MO
ND
BLUFF W
EST
MIE
SVILLE
Index to 7.5-Minute Quadrangles(Boundaries of individual quadrangles shown on 1:100,000-scale map)
SAND AND GRAVEL SOURCES
Sand and gravel deposits were mapped and named as simple land forms (Table
1) and divided into different classifications (Table 2) using various criteria.
Several operators and consultants in the aggregate industry, staff of the
Materials Division of the Minnesota Department of Transportation and the
Division of Minerals of the Minnesota Department of Natural Resources helped
to establish the criteria. Deposits are classified by percentage of material
retained on the number 4 sieve (4.76-millimeter pore space), sand and gravel
thickness, thickness of overlying deposits, location of the water table, and
relative amounts of subsurface information available (Table 2).
Source Evaluation
Primary Sources—For classification as a primary source, the following criteria
must be met: (1) more than 20 percent of the material is retained on a number
4 sieve; (2) the deposit is thicker than 10 feet; and (3) overlying sediment is
no thicker than 10 feet.
Quality of source where the water table is more than 20 feet below land surface
(classifications 1, 2, 3, and 6):
Quality of sources where the water table is less than 20 feet below land sur-
face (classifications 7 and 8):
Moderate to poor (generally more than 5 percent total spall
materials)
Good to moderate (less than 5 percent total spall materials)
Excellent to good (less than 1.5 percent total spall materials)
Moderate to poor (generally more than 5 percent total spall materials)
Good to moderate (less than 5 percent total spall materials)
Excellent to good (less than 1.5 percent total spall materials)
Secondary Sources—A secondary source must meet one or more of the
following conditions: (1) less than 20 percent of the material is retained on
a number 4 sieve; and/or (2) the deposit is less than 20 feet thick; and/or
overlying sediment is more than 10 feet.
Potential secondary source—Classifications 4 and 5
Gravel pit—Active or inactive pit
Large gravel pit, or an area of more than one gravel pit or gravel-
pit operation
MPO4
The first twoletters representthe deposit name
The third letter represents the typeof deposit
The numberrepresents theclass of thedeposit
Four-character code indicating deposit
name, deposit type, and aggregate-
quality classification—In the example
shown, the code indicates a deposit
named Minneapolis outwash that has
a classification of 4. Refer to Tables
1 and 2 for further information.
PROPORTION OF THICKNESS OF THICKNESS
MATERIAL RETAINED SAND & GRAVEL OF OVERLYING POSITION OF
ON NO. 4 SIEVE1 DEPOSIT SEDIMENTS WATER TABLE QUALITY OF SUBSURFACE DATA
1 More than 20% and More than 40 ft and 10 ft or less More than 20 ft Good subsurface data: Deep Minn. Dept. of Transportation test
below land surface borings or many detailed water-well records from several drillers
2 More than 20% and 10–40 ft and 10 ft or less More than 20 ft Good subsurface databelow land surface
3 More than 20% and More than 20 ft and 10 ft or less More than 20 ft Limited subsurface data: Few borings or water-wellbelow land surface records. Soil maps and surficial geology suggest the
presence of gravel deposits. Some good deposits probablyavailable, but boundaries uncertain.
4 Less than 20% and/or Less than 20 ft and/or More than 10 ft May be less Limited subsurface data. Few or no soil-boring or
than 20 feet water-well records, or well records are too generalized. Soilbelow land surface maps and surficial geology indicate possible sand and gravel
deposits. Good deposits may be present in places, but inmost cases this classification represents gravel-poor sanddeposits or thick sand overlying gravel.
5 Less than 20% and/or Less than 10 ft and/or More than 10 ft May be less Good subsurface data
than 20 feetbelow land surface
6 More than 20% and 10–40 ft thick and 10 ft or less More than 20 ft Good to fair subsurface data. Presence of carbonate bedrockover dolostone below land surface generally well established, but percentage of gravel in overlying
sediments may vary, especially in the larger areas mapped.
7 More than 20% and More than 20 ft and 10 ft or less Less than 20 ft Good subsurface databelow land surface
8 More than 20% and More than 20 ft and 10 ft or less Less than 20 ft Limited subsurface data. Few soil-boring or water-wellbelow land surface records. Soil maps and surficial geology suggest gravel
deposits. Good deposits probably available, butboundaries uncertain.
1The width of the pore space on a number 4 sieve is 4.76 millimeters.
Table 2. Numerical Classification of Sand and Gravel Deposits
CL
AS
SIF
I-
CA
TIO
N N
O.
Quarry
BEDROCK AGGREGATE SOURCES
Source Evaluation and Reliability of Data
The only available bedrock aggregate source in the Seven-County Metropolitan
Area is Prairie du Chien dolostone where overburden is thinner than ten feet.
Both quality and quantity of data determine how reliably the various units
of Prairie du Chien are delineated on the map. Information that was used
to map bedrock source units includes bedrock outcrops, water-well and soil-
boring records, soil maps, and topographic maps.
Excellent Reliability—Areas shown as having excellent reliability are char-
acterized by
1. outcrops of Prairie du Chien dolostone;
2. numerous, evenly distributed water-well and soil-boring records that
indicate carbonate bedrock at less than ten feet below the land surface;
3. soils characterized by parent material or substratum of carbonate bed-
rock; and
4. the presence of bluffs, flat plateaus, ridges, or rock terraces—landforms
that typically form in areas underlain by carbonate bedrock.
Good reliability—Areas shown as having good reliability are delineated using
criteria 3 and 4 above and criterion 1 or 2. Characteristically, areas mapped
as having good reliability have fewer outcrops and water-well and soil-bor-
ing records. Where such data are available, they are not as evenly distrib-
uted as those in areas mapped as having excellent reliability
Fair reliability—Areas shown as having fair reliability are delineated mainly
by criteria 3 and 4. The mapping is primarily based on soil maps and topo-
graphic expression. There are no outcrops and only a few water-well and
soil-boring records to support the distribution of bedrock shown.
Large quarry, or area of more than one quarry or quarry operation
Excellent reliability
Good reliability
Fair reliability
Excellent reliability
Good reliability
Fair reliability
Excellent reliability
Good reliability
Fair reliability
Where Prairie du Chien dolostone is thicker than 30 feet.
Where Prairie du Chien dolostone is 10–30 feet thick.
Where Prairie du Chien dolostone is less than 10 feet thick.