R 22 E R 23 E R 18 E FOND DU LAC CO R 19 E R 20 E SHEBOYGAN CO R 21 E

1 6 1 6 6 1 6 1 6 1 6 45 Preliminary bedrock geologic map 28 32 43 57 Sm Sm Sr of Walworth, Racine, Kenosha, 28 41 144 Sr

T 12 N Milwaukee, Waukesha, Ozaukee, On Dlc

Sm Swb Milwaukee

and Washington Counties Milwaukee Sm

36 31 36 31 Om 36 31 36 31 36 31

1 6 6 6 T. J. Evans, K.M. Massie-Ferch, 1 1 6 1 1 6 and R.M. Peters Sr 175 Sr 33 OZAUKEE T 11 N

33 River Sr 2004 Sm Om Om

On Sm Sr 33 EXPLANATION DODGE CO Sm

ake 31 Map units shown are covered by younger, unconsolidated sediment varying in thickness from a few feet to more than 500 feet. 36 31 36 36 31 31 36 31 POST- C e d a r L 32 L 6 1 6 1 6 Lamprophyre 6 1 6 1 Sm WASHINGTON DEVONIAN 57 Dlc Sm Sr 45 Sr Sm U Da Antrim Shale. Mudstone to very argillaceous dolomite; dark gray to black. Sm D

Dm . Argillaceous dolomite, dolomitic siltstone, and shale; gray; locally fossiliferous.

T 10 N D Dt Theinsville Formation. Dolomite, argillaceous dolomite, and dolomitic siltstone; brown to brownish gray; some . U

Dt/Dlc Theinsville and Lake Church Formations, undifferentiated. Sr River Sm Sr Dlc Lake Church Formation. Argillaceous dolomite, and dolomite; brownish gray; locally fossiliferous. On Om 31 36 31 Sr 36 31 31 31 41 36 36

Swb Waubakee Formation. Dolomite, very fine grained, thin-bedded, dark to light gray. Ske 32 6 1 6 1 6 1 1 6 6 43

Sr Racine Formation. Dolomite, medium to coarse grained, thin- to thick-bedded, very light to light gray; fossiliferous. Dt/Dlc Om Sr Om Manistique Formation. Dolomite, fine to medium grained, thin- to medium-bedded, light to medium gray. Sm L Sr

Sw Waukesha Formation. Dolomite, medium grained, thin- to medium-bedded, light to medium gray, locally cherty. Sm A T 9 N On

U Sm K Sbr Brandon Bridge Formation. Dolomite, very argillaceous, pale green to pink. Sm Sm 175 D

Ske Kankakee Equivalent. Dolomite, fine to medium grained, light to medium gray, locally cherty and fossiliferous. E Ske Ske On Dt/Dlc Sm 57

31 31 On . Oolite, red brown, hematitic; shale, red brown, dolomitic. 36 31 36 31 36 31 36 R 17 E M Os Om . Shale, greenish gray to purplish; dolomite, very 6 Os 32 1 6 Ske 1 6 1 6 1 6 41 1 6 argillaceous, tan. 45 Sr 43 I

Os Sinnipee Group. Dolomite, tan to buff in color, thin to medium-bedded, R i v e r Dt Dt C fossiliferous, locally cherty. 67 Ske 175 Dm

Milwaukee H Sr Dm SYMBOLS Sw T 8 N I Contact Os Bark G ? Transitional contact Lac La Bel l e

e e c h A u a e Data point k k O L a Sr U 16 N Fault. General direction of movement indicated by upthrown or downthrown. 31 Sw Swb 31 31 36 D 36 36 31 36 31 36 41 31

6 Oconomowoc Lake 1 6 1 6 1 6 6 1 6 1 River Ske 190

Os 190 Sr Os Dm Da Sw LAKE 16 1012345678 94 Ske KILOMETERS P E W A U K E E U 10123 45 T 7 N D Da MILES Ri ver 43 COUNTY INDEX Sw MILWAUKEE Dt

D Ske Sr 18 18 Shade relief of bedrock surface vertical exaggeration 5x U

94 Wisconsin Transverse Mercator Projection 36 31 31 36 31 36 31 31 36 31 1991 adjustment to the North American Datum of 1983 (NAD 83/91) 18 WAUKESHA 94 36

JEFFERSON CO

6 Bark 1 6 1 U 6 1 6 1 6 1 6 Os 67 D 59

U Sw 15 D Sr This map represents work performed by the Wisconsin Geological and Natural Ske History Survey and is released to the open files in the interest of making Sw Sr the information readily available. This map has not been edited or reviewed Sr for conformity with Wisconsin Geological and Natural History Survey T 6 N standards and nomenclature. Ske Sw 15 This map is part of an ongoing project funded by STATEMAP, the state component 894 of the National Cooperative Geologic Mapping Program of the U.S. Geological Survey. Ske Sw

36 36 31 31 31 36 31 36 31 36 31 36

Sr 6 1 1 6 1 6 1 6 1 6 1 6 Sbr Ske Wisconsin Geological and Natural History Survey River Sw 3817 Mineral Point Road, Madison, Wisconsin 53705-5100 Om Om Os phone 608/263-7389 fax 608/262-8086 www.uwex.edu/wgnhs/ Ske Sbr Sw 32 41 Sr Sbr James M. Robertson, Director and State Geologist 83 Sbr Fox Sw T 5 N Data entry and processing by K.K. Zeiler. Cartography by D.L. Patterson. 59 Om 15 36 94

Sr Om Muskego Lake

Ske 36 Om 67

31 Sw 36 31 36 36 31 36 36 36 31 31 31 31 Sw R 15 E JEFFERSON CO R 16 E

Sw D U 1 6 6 6 1 6 1 6 1 6 1 6 1 6 1 6 1 Ske Sw Sw Sbr 32 12

67 Os 15

83 Sw 31 Ske Sr Sr

T 4 N 36 Sr Sw 20 Sr 41 94

Os 45 Sw 20 Sw 36 31 36 36 31 36 31 36 31 36 31 Sr 31 31 36 31 36 31 RACINE

Om 6 Sw 6 6 1 1 1 6 1 6 1 6 6 1 6 1 6 1 Sw

R I V E R

12 Sbr Sw Ske 20 Sw Sr Sr

T 3 N Ske 32 89 11 FOX Sw Om Om D Sbr U Sr 11 11

Ske Om Sw 36 31 36 31 36 31 36 31 36 31 31 Os 36 31 36 31 36 31 Sbr WALWORTH 36 Sbr

1 6 1 6 1 6 1 6 6 1 6 1 6 ROCK CO ROCK 6 1 6 1

14 11 83 Sbr

Om Sbr Sr 67 50

T 2 N Ske Ske 36 45

FOX Om Sw 15 KENOSHA Del avan Lake Lake Como 31 36 31 36 31 36 36 31 31 36 31 36 31 36 31 Ske 31 36

6 50 1 1 6 1 6 1 6 6 1 6 1 L 6 1 6 6 1 50

L A K E G E N E V A RI VER Sw 41

94 Sr Os

T 1 N Om Sw 31 Ske

Ske Sw 32 14 12 Ske 67

36 31 31 36 31 36 31 36 31 36 31 36 31 36 36 31 31 Sr

R 19 E R 20 E R 16 E R 18 E R 21 E R 15 E R 17 E ILLINOIS R 22 E R 23 E

Wisconsin Geological and Natural History Survey Open-File Report 2004-18