In cooperation with the State of Michigan, Department of Environmental Quality

Summary of Hydrogeologic Conditions by County for the 

State of Michigan

U.S. Department of the Interior

U.S. Geological Survey

Open-File Report 2007-1236
Summary of Hydrogeologic Conditions by 

County for the State of Michigan

By Beth A. Apple and Howard W. Reeves

In cooperation with the State of Michigan, Department of Environmental Quality

Open-File Report 2007-1236 

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2007

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation

Beth, A. Apple and Howard W. Reeves, 2007, Summary of Hydrogeologic Conditions by County for the State of Michigan. U.S. Geological Survey Open-File Report 2007-1236, 78 p.

Cover photographs

Clockwise from upper left: Photograph of Pretty Lake by Gary Huffman. Photograph of a river in winter by Dan 

Wydra. Photographs of Lake Michigan and the Looking Glass River by Sharon Baltusis.
Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Purpose and Scope ..............................................................................................................................1

Study Area.......................................................................................................................................................1

County Summaries.........................................................................................................................................3

Alcona County .......................................................................................................................................3

Alger County ..........................................................................................................................................3

Allegan County ......................................................................................................................................4

Alpena County .......................................................................................................................................5

Antrim County........................................................................................................................................6

Arenac County.......................................................................................................................................6

Baraga County.......................................................................................................................................8

Barry County..........................................................................................................................................8

Bay County.............................................................................................................................................9

Benzie County......................................................................................................................................10

Berrien County.....................................................................................................................................11

Branch County.....................................................................................................................................11

Calhoun County ...................................................................................................................................12

Cass County .........................................................................................................................................13

Charlevoix County...............................................................................................................................13

Cheboygan County..............................................................................................................................14

Chippewa County................................................................................................................................15

Clare County.........................................................................................................................................16

Clinton County......................................................................................................................................17

Crawford County .................................................................................................................................18

Delta County.........................................................................................................................................18

Dickinson County ................................................................................................................................19

Eaton County........................................................................................................................................20

Emmet County......................................................................................................................................22

Genesee County..................................................................................................................................23

Gladwin County ...................................................................................................................................24

Gogebic County...................................................................................................................................25

Grand Traverse County ......................................................................................................................26

Gratiot County......................................................................................................................................27

Hillsdale County...................................................................................................................................28

Houghton County.................................................................................................................................29

Huron County.......................................................................................................................................29

Ingham County.....................................................................................................................................31

Ionia County.........................................................................................................................................32

Iosco County........................................................................................................................................33

Iron County...........................................................................................................................................34

Isabella County....................................................................................................................................35

Jackson County...................................................................................................................................35

Kalamazoo County ..............................................................................................................................36

Kalkaska County..................................................................................................................................37

iii
Figures

1. Location of counties in Michigan.................................................................................................2

Kent County..........................................................................................................................................37

Keweenaw County..............................................................................................................................39

Lake County..........................................................................................................................................39

Lapeer County......................................................................................................................................40

Leelanau County..................................................................................................................................41

Lenawee County..................................................................................................................................42

Livingston County................................................................................................................................43

Luce County .........................................................................................................................................44

Mackinac County................................................................................................................................45

Macomb County..................................................................................................................................46

Manistee County.................................................................................................................................47

Marquette County...............................................................................................................................47

Mason County......................................................................................................................................48

Mecosta County..................................................................................................................................49

Menominee County.............................................................................................................................49

Midland County ...................................................................................................................................50

Missaukee County ..............................................................................................................................51

Monroe County....................................................................................................................................51

Montcalm County................................................................................................................................53

Montmorency County.........................................................................................................................53

Muskegon County...............................................................................................................................54

Newaygo County.................................................................................................................................55

Oakland County ...................................................................................................................................56

Oceana County....................................................................................................................................57

Ogemaw County..................................................................................................................................57

Ontonagon County ..............................................................................................................................58

Osceola County ...................................................................................................................................59

Oscoda County ....................................................................................................................................59

Otsego County .....................................................................................................................................59

Ottawa County.....................................................................................................................................60

Presque Isle County............................................................................................................................61

Roscommon County............................................................................................................................62

Saginaw County ..................................................................................................................................62

Sanilac County.....................................................................................................................................63

Schoolcraft County.............................................................................................................................64

Shiawassee County............................................................................................................................65

St. Clair County....................................................................................................................................66

St. Joseph County...............................................................................................................................67

Tuscola County ....................................................................................................................................68

Van Buren County ...............................................................................................................................69

Washtenaw County ............................................................................................................................69

Wayne County .....................................................................................................................................71

Wexford County...................................................................................................................................72

 References Cited.........................................................................................................................................73

iv
Conversion Factors, Abbreviations, and Vertical Datum

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

acre 4,047 square meter (m2)

square foot (ft2) 0.09290 square meter (m2)

square inch (in2) 6.452 square centimeter (cm2)

section (640 acres or 1 square mile) 2.59 square kilometer (km2)

square mile (mi2) 2.590 square kilometer (km2) 

Volume

gallon (gal) 3.785 liter (L) 

gallon (gal) 0.003785 cubic meter (m3) 

million gallons (Mgal) 3,785 cubic meter (m3)

cubic foot (ft3) 0.02832 cubic meter (m3) 

cubic yard (yd3) 0.7646 cubic meter (m3) 

acre-foot (acre-ft) 1,233 cubic meter (m3)

Flow rate

acre-foot per day (acre-ft/d) 0.01427 cubic meter per second (m3/s)

acre-foot per year (acre-ft/yr) 1,233 cubic meter per year (m3/yr)

foot per second (ft/s) 0.3048 meter per second (m/s)

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

cubic foot per second per square

mile [(ft3/s)/mi2]

 0.01093 cubic meter per second per square

kilometer [(m3/s)/km2]

cubic foot per day (ft3/d) 0.02832 cubic meter per day (m3/d)

gallon per minute (gal/min) 0.06309 liter per second (L/s)

gallon per day (gal/d) 0.003785 cubic meter per day (m3/d)

gallon per day per square mile

 [(gal/d)/mi2]

 0.001461 cubic meter per day per square

kilometer [(m3/d)/km2]

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3/s)

million gallons per day per square

mile [(Mgal/d)/mi2]

1,461 cubic meter per day per square

kilometer [(m3/d)/km2]

mile per hour (mi/h) 1.609 kilometer per hour (km/h) 

Specific capacity

gallon per minute per foot 

[(gal/min)/ft)]

 0.2070 liter per second per meter [(L/s)/m]

Hydraulic conductivity

foot per day (ft/d) 0.3048 meter per day (m/d)

Hydraulic gradient

foot per mile (ft/mi) 0.1894 meter per kilometer (m/km)

Transmissivity*

foot squared per day (ft2/d) 0.09290 meter squared per day (m2/d) 

v
Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Altitude, as used in this report, refers to distance above the vertical datum.

*Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times foot 

of aquifer thickness [(ft3/d)/ft2]ft. In this report, the mathematically reduced form, foot squared per day 

(ft2/d), is used for convenience.

vi
Abstract

Summaries of the major hydrogeologic features for 

each county in Michigan are presented. Each summary 

includes a listing of the major watersheds in the county and 

a description of the hydrogeology of the major aquifers in 

the county. Aquifer properties reported in the literature are 

given if available. Reports describing the hydrogeology of 

each county are cited. This work was prepared to provide 

a brief introduction to the ground‐water setting for each 

county.

Introduction

Purpose and Scope

Public Act 148, Section 32802 (Michigan State 

Legislature, 2003) required the Department of Environmen‐

tal Quality (MDEQ) of the State of Michigan to create a 

ground‐water inventory and map that includes eight specific 

requirements, a general requirement for a ground‐water 

inventory, and a directive to make the map and inventory 

accessible by the public. This document provides a sum‐

mary of hydrogeologic conditions for each county in the 

State that were prepared for the ground‐water inventory.

The goal of the effort documented by this report was 

to provide a database of hydrogeologic information for 

the State. This database indexes reports that describe the 

hydrogeology and ground‐water resources of the State of 

Michigan, provides aquifer‐test results from these reports, 

and provides an overview summary of the hydrogeologic 

conditions for each county. The database may be searched 

by county, hydrologic unit code, aquifer type, author, and 

various other fields. The database is provided on‐line and 

is envisioned to provide a first‐stop for State regulators, 

water‐resources professionals, and the public to gather 

existing ground‐water resources data for Michigan. The 

county summaries prepared for the database are provided 

in this report.

For each county summary, the distribution of wells 

between wells completed in bedrock aquifers and those 

glacial deposits is provided using records from the digital 

water well log database, Wellogic, maintained by the 

State of Michigan. This distribution is intended to indicate 

the major local aquifer system used for domestic supply 

to the reader. Each summary then describes the aquifer 

characteristics for post‐glacial alluvium, glacial deposits, 

and bedrock units. Citations are provided to document the 

summary. The level of detail for each county depends on 

the available information for the county, and no additional 

interpretive work was done in the preparation of these 

summaries. Many of the reports cited in this report are 

available through the internet at the ground‐water inven‐

tory and map website that is maintained by Michigan State 

University (http://gwmap.rsgis.msu.edu).

Study Area

The study area for this report is the entire State of 

Michigan. This report is a compilation of county hydro‐

geologic summaries created for the ground‐water inven‐

tory. Each county summary is designed to provide a brief 

overview of the ground‐water resources in the county.

Summary of Hydrogeologic Conditions by County for the 

State of Michigan

By Beth A. Apple and Howard W. Reeves
Base from U.S. Geological Survey 1:500,000 map

90o

48o

89o

47o

88o

87o

84o

46o

45o

83o

44o

43o

42o

86o

85o

LEELANAU

EMMET CHEBOYGAN

PRESQUE ISLE

CHARLEVOIX

ANTRIM OTSEGO

MONTMORENCY ALPENA

BENZIE GRAND

TRAVERSE

KALKASKA CRAWFORD OSCODA ALCONA

MANISTEE WEXFORD MISSAUKEE

ROSCOMMON

OGEMAW IOSCO

MASON LAKE OSCEOLA CLARE GLADWIN ARENAC

OCEANA NEWAYGO MECOSTA ISABELLA MIDLAND BAY

HURON

MUSKEGON KENT

MONTCALM GRATIOT SAGINAW

TUSCOLA SANILAC

OTTAWA IONIA CLINTON SHIAWASSEE

GENESEE LAPEER

ALLEGAN BARRY EATON INGHAM LIVINGSTON

OAKLAND

VAN BUREN KALAMAZOO CALHOUN JACKSON WASHTENAW WAYNE

BERRIEN

CASS ST JOSEPH BRANCH HILLSDALE LENAWEE MONROE

MACOMB

ST CLAIR

KEWEENAW

HOUGHTON

ONTONAGON

GOGEBIC

IRON

BARAGA MARQUETTE

DICKINSON

ALGER

MENOMINEE

DELTA

SCHOOLCRAFT

LUCE

MACKINAC

CHIPPEWA

89o

0 10 20 30 40 50 MILES

0 20 40 60 KILOMETERS

SAGINAW

 BAY

LA

KE

MICHIGAN

LAKE HURON

LAKE ERIE

LAKE SUPERIOR

439

 Summary of Hydrogeologic Conditions by County for the State of Michigan

Figure 1. Location of counties in Michigan.
County Summaries

Alcona County

Alcona County is in the northeastern portion of the 

Lower Peninsula of Michigan. The Lone Lake‐Ocqueoc, 

Thunder Bay, Au Sable, and Lake Huron watersheds drain the 

county. According to the February 2005 Wellogic database, 

approximately 94 percent of the wells in Alcona County are 

completed in the glacial deposits, and less than 1 percent in 

the bedrock units. There is insufficient information to make 

this distinction for 6 percent of the wells in the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface in the Michigan 

Basin. This is likely due to the lateral and vertical hetero‐

geneity of glacial deposits that resulted from a complex 

depositional history (Westjohn and others, 1994). The glacial 

deposits in Alcona County range from 101 to 800 ft thick. 

However, the majority of the deposits range from 201 to 600 ft 

thick (Western Michigan University, 1981). The glacial depos‐

its consist of till, outwash, and lacustrine deposits. Fine‐ to 

coarse‐grained till occurs in moraines and till plains. Glacial 

outwash and ice‐contact outwash is also present in the county, 

and primarily consists of sand and gravel. Coarse‐grained 

lacustrine deposits are present on the surface in the south‐cen‐

tral, southeastern, and northeastern portions of the county 

(Farrand and Bell, 1982). Aquifers in the glacial deposits 

consist largely of sands and gravels and vary regionally in 

thickness and permeability.

Bedrock underlies the glacial deposits. The bedrock 

surface of Alcona County is composed of the Marshall Sand‐

stone, Coldwater Shale, Sunbury Shale, Berea Sandstone, 

Bedford Shale, and Antrim Shale (Milstein, 1987). The Mar‐

shall Sandstone forms the bedrock surface in the southwestern 

portion of the county. The Marshall Sandstone consists of one 

or more stratigraphically continuous permeable sandstones. 

The upper sandstone is a quartzarenite to sublitharenite that 

is referred to as the Napoleon Sandstone Member. A shale, 

siltstone, and/or carbonate layer separates the Napoleon Sand‐

stone Member from the underlying lower Marshall sandstone. 

The lower Marshall sandstone is comprised of two units. The 

upper unit is generally 50 to 125 ft of fine‐ to medium‐grained 

quartzarenite to sublitharenite. The basal unit is a fine‐ to 

medium‐grained litharenite that ranges in thickness from 30 

to 125 ft. Permeable sandstones in the Marshall Sandstone 

comprise the Marshall aquifer. The Marshall aquifer ranges 

in thickness from 75 to greater than 200 ft within the State 

(Westjohn and Weaver, 1998). The Marshall aquifer contains 

fresh water in Alcona County (Westjohn and Weaver, 1996c).

The Coldwater Shale underlies the Marshall Sandstone, 

and consists of primarily shale with interbeds or lenses of 

sandstone, siltstone, and dolomite. The Coldwater Shale is 

relatively impermeable and is considered a confining unit in 

most of Michigan (Westjohn and Weaver, 1998).

The Sunbury Shale is a black, carbonaceous shale that 

underlies the Coldwater Shale (Harrell and others, 1991). The 

Sunbury Shale thins towards the center of the Michigan Basin 

and is 147.6 ft thick in the eastern portion of the State (Guts‐

chick and Sandberg, 1991). Shale is generally considered to be 

a confining unit.

The Berea Sandstone underlies the Sunbury Shale. The 

Berea Sandstone is fine‐ to medium‐grained sandstone, and 

is greater than 114.8 ft thick in eastern Michigan and thins to 

the west (Gutschick and Sandberg, 1991). The Berea Sand‐

stone grades into the underlying Bedford Shale and thus the 

upper portion of the shale is silty or sandy. The Bedford Shale 

is primarily gray shale in the Michigan Basin. The Bedford 

Shale may be greater than 213.3 ft thick in eastern Michigan 

and thins toward the center of the Michigan Basin (Gutschick 

and Sandberg, 1991). Shale is generally considered to be a 

confining unit.

The Antrim Shale is composed of primarily carbona‐

ceous, black to dark‐gray shale. Near the base of the sequence, 

thin layers of gray shale and limestone may occur. The major 

constituents in the Antrim Shale consist of quartz, illite, and 

kerogen. Kaolinite, chlorite, and pyrite also compose the Ant‐

rim Shale. The Antrim Shale has been found to have bitumi‐

nous limestone concretions up to 3 ft in diameter (Matthews, 

1993). The Antrim Shale can be up to 656 ft thick, which 

occurs at the center of the Michigan Basin (Gutschick and 

Sandberg, 1991). Antrim Shale is generally not considered to 

be an aquifer, however, locally it may yield small quantities of 

water.

Alger County

Alger County is in the central portion of the Upper 

Peninsula of Michigan. The Betsy‐Chocolay, Tahquamenon, 

Lake Superior, Tacoosh‐Whitefish, Fishdam‐Sturgeon, and 

Manistique watersheds drain the county. According to the 

February 2005 Wellogic database, approximately 28 percent of 

the wells in Alger County are completed in the glacial depos‐

its, and 68 percent in the bedrock units. There is insufficient 

information to make this distinction for 4 percent of the wells 

in the county. The glacial aquifer is generally unconfined, and 

overlies the bedrock aquifers, except where glacial deposits 

are absent.

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

With the available information, glacial lithologies cannot be 

regionally correlated in the subsurface. This is likely due to 

the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). The glacial deposits range from 0 to greater than 

200 ft thick in Alger County, and include lacustrine deposits, 

till, and outwash. Sand is the major constituent in lacustrine 

deposits, which locally overlie other types of glacial deposits. 

The lacustrine deposits yield moderate supplies of water. Till 

is present in moraines and till plains. The Munising and New‐

County Summaries 
berry Moraines are present in Alger County. The Munising 

Moraine trends from the northeast to the southwest. The New‐

berry Moraine is present in T45N R19W and T44N R19W. 

The moraines are composed primarily of sandy till with lenses 

of sand and gravel outwash interbedded. The morainal depos‐

its may yield small to moderate supplies of water. Till‐plain 

deposits, which consist of sandy‐clay or boulder till, generally 

do not supply water. The outwash deposits consist of primar‐

ily sand and some gravel (Vanlier, 1963b). Where the outwash 

deposits are the most extensive, Vanlier (1963b) estimates the 

average thickness to be 100 ft. Outwash deposits may yield 

moderate to large water supplies, which locally has high iron 

content.

Specific capacities range from 1 to 14 gal/min/ft for the 

glacial aquifer in Pictured Rocks National Lakeshore (Handy 

and Twenter, 1985). Based upon eight wells located near the 

Wetmore tribal community, glacial aquifer transmissivity 

ranges from 95 to 310 ft2/day (Brannen, 1997). According to 

the Public Water Supply database, the estimated transmissiv‐

ity for glacial wells in the county ranges from approximately 

2,150 to 5,615 ft2/day.

Glacial deposits, when present, overlie the bedrock units. 

The units that form the bedrock surface generally subcrop 

trending southwest to northeast. The youngest units form the 

bedrock surface in the southeastern portion of the county and 

get progressively older to the northwest. Due to the angle 

of the bedrock, which dips south, the layers diminish to the 

north. The Trenton Formation and underlying Black River 

Formation, which are composed of limestone and dolomite 

with interbedded shale, are the uppermost bedrock units in the 

county. This combined layer is thinner in the northern portion 

of the county and is the major source of water in the south‐

western portion of the county. The Trenton and Black River 

Formations supply small yields of hard water with high iron 

concentrations. Bacterial contamination is also a problem in 

water from this layer. In some areas, impermeable layers in the 

Trenton and Black River Formations act as confining layers 

(Vanlier, 1963b).

Vanlier (1963b) defines the bedrock underlying the Tren‐

ton and Black River Formations as Ordovician and Cambrian 

dolomite and sandstone undifferentiated. Handy and Twenter 

(1985) define this same layer as the Prairie du Chien Group 

and underlying Trempealeau Formation. Dolomite in this layer 

can supply small amounts of water, usually in the western 

part of Alger County, where the sandstone from this layer is 

thin or not present. In other areas of the county, the sandstone 

member supplies water. Based on nine wells completed in the 

Prairie du Chien Group, near the Wetmore tribal community, 

bedrock aquifer transmissivity ranges from 6.7 to 26.7 ft2/day 

(Brannen, 1997). The Munising Formation and Jacobsville 

Sandstone underlie this layer.

The Munising Formation is composed of a fine‐ to medi‐

um‐grained quartz sandstone, with lenses of coarser sandstone, 

and a basal conglomerate layer. The Munising Formation 

supplies good quality water and is the most extensive aquifer 

in Alger County. However, the Munising Formation does not 

supply many wells with water, because shallower ground‐wa‐

ter resources are available. The Munising Formation may be 

semi‐confined or confined in areas because the upper portion 

of the formation is silty to shaley (Vanlier, 1963b). Specific 

capacities are near 1 gpm/ft for the Munising Formation in 

Pictured Rocks National Lakeshore (Handy and Twenter, 

1985). According to the Public Water Supply database, the 

estimated transmissivity for wells completed in the Munising 

Formation is approximately 535 ft2/day.

The Jacobsville Sandstone, which lies underneath the 

Munising Formation, is moderately permeable from joints 

and fractures in the upper third of the formation, especially 

where it forms the bedrock surface. The greatest thickness 

of Jacobsville Sandstone is 1,000 ft along the shore of Lake 

Superior and thins to the south. Jacobsville Sandstone is pre‐

dominately medium‐grained sandstone interbedded with shale, 

siltstone, and coarser sandstone (Vanlier, 1963b). Specific 

capacities range between 0.1 to 1 gal/min/ft for the Jacobsville 

Sandstone in Pictured Rocks National Lakeshore (Handy and 

Twenter, 1985). The Jacobsville Sandstone supplies hard water 

with high concentrations of iron. In some wells, the water 

from Jacobsville Sandstone is saline (Vanlier, 1963b). Igneous 

and metamorphic Precambrian rocks underlie the Jacobsville 

Sandstone and are not a source of water (Handy and Twenter, 

1985).

 Allegan County

Allegan County is in the southwestern Lower Peninsula 

of Michigan. The western edge of the county is along the Lake 

Michigan shoreline. The Lake Michigan, Black-Macatawa, 

Kalamazoo, Lower Grand, and Thornapple watersheds drain 

the county. According to the February 2005 Wellogic data‐

base, approximately 89 percent of the wells in Allegan County 

are completed in the glacial deposits, and 8 percent in the 

bedrock units. There is insufficient information to make this 

distinction for 3 percent of the wells in the county.

With the available information in the State, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). The surficial deposits in 

Allegan County consist of dunes, lacustrine deposits, outwash 

and small amounts of post‐glacial alluvium, and till. Dune 

sand primarily exists in the western portion of the county 

along Lake Michigan. Lacustrine deposits are primarily sand 

and gravel and are concentrated in the center of the county. 

Outwash and post‐glacial alluvium deposits occur mostly in 

the eastern portion of the county and are composed of sand 

and gravel. Till is present in till plains and moraines. The till 

in Allegan County ranges from fine to coarse grained (Farrand 

and Bell, 1982).

Aquifers in the glacial deposits consist largely of sands 

and gravels, and vary regionally in thickness and permeability. 

According to the Public Water Supply database, the outwash 

 Summary of Hydrogeologic Conditions by County for the State of Michigan
deposits have estimated transmissivities from aquifer tests that 

range from 9,547 to 79,900 ft2/day, while combined outwash 

and till have an estimated transmissivity of 6, 496 ft2/day.

Bedrock underlies the glacial deposits. The bedrock sur‐

face in Allegan County is composed of the Michigan Forma‐

tion, Marshall Sandstone, and Coldwater Shale. The Michigan 

Formation subcrops in a small area in the northeastern portion 

of the county. Discontinuous siltstone and sandstone lenses, 

along with shale, carbonate, and evaporite comprise the 

Michigan Formation. The Michigan Formation is considered a 

confining unit (Westjohn and Weaver, 1996b).

The Marshall Sandstone underlies the Michigan Forma‐

tion and subcrops in the northeastern portion of the county. 

The greatest thickness of the Marshall Sandstone is 171 ft in 

Allegan County (Riggs, 1938). The Marshall Sandstone is 

composed of an upper quartzarenite to sublitharenite that is 

referred to as the Napoleon Sandstone Member (Riggs, 1938). 

A shale, siltstone, and/or carbonate layer separates the Napo‐

leon Sandstone Member from the lower Marshall sandstone. 

The lower Marshall Sandstone is comprised of two units. The 

upper unit is generally 50 to 125 ft of fine‐ to medium‐grained 

quartzarenite to sublitharenite. The basal unit is a fine‐ to 

medium‐grained litharenite that ranges in thickness from 30 

to 125 ft (Westjohn and Weaver, 1998). Both the Napoleon 

Sandstone Member and lower Marshall Sandstone are pres‐

ent in well logs from Allegan County (Riggs, 1938). Perme‐

able sandstones in the Marshall Sandstone are considered the 

Marshall aquifer. The Marshall aquifer ranges in thickness 

between 75 and greater than 200 ft thick within the State 

(Westjohn and Weaver, 1998). The Marshall aquifer yields 

fresh water in Allegan County (Westjohn and Weaver, 1996c).

The Coldwater Shale underlies the Marshall Sandstone. 

The Coldwater Shale subcrops in the central and western por‐

tion of Allegan County. In the County, the Coldwater Shale 

ranges from 700 to 860 ft thick when beneath the Marshall 

Sandstone. Coldwater Shale consists of shale, sandstone, 

siltstone, and carbonates. In Allegan County, cherty shale that 

contains dolomite crystals, chert bands and dolomitic lime‐

stone are common in the Coldwater Shale. Limestone layers 

may provide water to wells in areas of the county. However, 

the water may be saline (Riggs, 1938).

 Alpena County

Alpena County is in the northeastern Lower Peninsula of 

Michigan. The Lone Lake-Ocqueoc, Thunder Bay, Au Sable, 

and Lake Huron watersheds drain portions of Alpena County. 

According to the February 2005 Wellogic database, approxi‐

mately 39 percent of the wells in Alpena County are com‐

pleted in the glacial deposits, and 41 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 20 percent of the wells in the county. Glacial wells are 

more abundant in the southern portion of the county, while 

bedrock wells dominate the northern portion of the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). Glacial deposits are up to 600 ft 

thick in Alpena County (Western Michigan University, 1981). 

The glacial deposits in the county consist of till, outwash, and 

lacustrine deposits. The western and central portion of the 

county is primarily composed of coarse‐grained till. Eskers 

are present in central portion of the county. Fine‐grained till 

can also be found on the surface, but does not make up a large 

percentage of the glacial deposits in the county. Outwash 

and ice‐contact outwash are found throughout the southwest‐

ern and southeastern portions of the county, respectively. 

Coarse‐grained lacustrine deposits are present on the surface 

in the northeastern portion of the county and along the eastern 

border. In addition, sand dunes composed of fine‐ to medi‐

um‐grained sand are present along the Lake Huron shoreline 

and are also found inland. An area of peat and muck deposits 

can be found in the northwestern portion of the county (Far‐

rand and Bell, 1982).

The glacial deposits overlie the bedrock. The bedrock 

surface of Alpena County is composed of the Sunbury Shale, 

Berea Sandstone, Bedford Shale, Antrim Shale, and Traverse 

Group. Sunbury Shale, Berea Sandstone, and Bedford Shale 

subcrop in the southwestern portion of the county. The Antrim 

Shale and Traverse Group form the remainder of the bedrock 

surface in the northern and southern portions of the county, 

respectively (Milstein, 1987).

The Sunbury Shale is a black shale, which thins towards 

the center of the basin and is 147 ft thick in the eastern portion 

of the State (Gutschick and Sandberg, 1991). The Berea Sand‐

stone underlies the Sunbury Shale. The Berea Sandstone is 

fine‐ to medium‐grained sandstone. It is greater than 114.8 ft 

thick in eastern Michigan and thins to the west (Gutschick and 

Sandberg, 1991). The Berea Sandstone grades into the under‐

lying Bedford Shale and thus the upper portion of the shale is 

silty or sandy. The Bedford Shale is primarily gray shale in the 

Michigan Basin. The Bedford Shale may be greater than 213 

ft thick in eastern Michigan and thins toward the center of the 

Michigan Basin (Gutschick and Sandberg, 1991).

The Antrim Shale is composed of primarily carbona‐

ceous, black to dark‐gray shale. Near the base of the sequence, 

thin layers of gray shale and limestone may occur. The major 

constituents in the Antrim Shale consist of quartz, illite, and 

kerogen. Kaolinite, chlorite, and pyrite also compose the Ant‐

rim Shale. The Antrim Shale has been found to have bitumi‐

nous limestone concretions up to 3 ft in diameter (Matthews, 

1993). The Antrim Shale can be up to 656 ft thick, which 

occurs at the center of the Michigan Basin (Gutschick and 

Sandberg, 1991).

The Traverse Group primarily consists of fossiliferous 

limestone. In the western portion of the basin, porous dolo‐

mite and anhydrite may be present. In the eastern portion of 

County Summaries 
the basin, interlayers of shale are common. (Gardner, 1974). 

The basal formation of the Traverse Group is the Bell Shale. 

Bell Shale has a maximum thickness of 80 ft (Catacosinos and 

others, 2001). The majority of the bedrock wells in the county 

occur where the Traverse group forms the bedrock surface.

There are several karst features that occur throughout the 

northern portion of the county. The karst features are a result 

of dissolution of the carbonate and evaporite bedrock units and 

subsequent collapse of these units. Karst sinkhole lakes occur 

near Leer in Alpena County. Devil’s, Long, Fitzgerald, and 

Mindack Lakes are considered karst solution lakes (Kimmel, 

1983).

Antrim County

Antrim County is in the northwestern Lower Peninsula. 

The Manistee, Boardman-Charlevoix, and Lake Michigan 

watersheds can be found in the county. According to the Feb‐

ruary 2005 Wellogic database, approximately 94 percent of the 

wells in Antrim County are completed in the glacial deposits, 

and less than 1 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 6 percent of 

the wells in the county. The majority of the bedrock wells are 

along the western shoreline.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). In Antrim County, the 

glacial deposits range from 11 to 1,000 ft thick; however, the 

majority of the deposits range from 200 to 800 ft in thickness 

(Western Michigan University, 1981). The glacial deposits are 

composed of outwash, till, and lacustrine deposits. Outwash 

consists of sand and gravel and is most abundant in the eastern 

portion of the county. An isolated area of ice‐contact outwash 

is in the southeastern corner of the county. The till found 

in Antrim County is primarily coarse grained and occurs in 

moraines and till plains. A small amount of medium‐grained 

till occurs in the southwestern portion of the county. Moraines 

trend southwest to northeast across the county. Drumlins are 

abundant on the till plains in the northwestern portion of the 

county. The lacustrine deposits are composed primarily of 

sand and gravel and are concentrated in the western portion of 

the county (Farrand and Bell, 1982). According to the Public 

Water Supply database, the estimated transmissivity for glacial 

wells ranges from approximately 1,200 to 14,170 ft2/day.

According to the Public Water Supply database, the 

estimated transmissivity for a bedrock well in the county is 

approximately 2,320 ft2/day. The bedrock surface in Antrim 

County consists of the Coldwater Shale, Sunbury Shale, Berea 

Sandstone, Bedford Shale, Antrim Shale, Ellsworth Shale, 

and Traverse Group (Milstein, 1987). Within the State, the 

Coldwater Shale consists of primarily shale with interbeds, or 

lenses, of sandstone, siltstone, and dolomite. The Coldwater 

Shale is relatively impermeable and is considered a confining 

unit in most of Michigan (Westjohn and Weaver, 1998).

The Sunbury Shale is black shale that thins towards the 

center of the basin and is 147.6 ft thick in the eastern por‐

tion of the State (Gutschick and Sandberg, 1991). This unit 

is generally not considered an aquifer. The Berea Sandstone 

underlies the Sunbury Shale. The Berea Sandstone is fine‐ to 

medium‐grained sandstone. It is greater than 114.8 ft thick in 

eastern Michigan and thins to the west. The Berea Sandstone 

grades into the underlying Bedford Shale and thus the upper 

portion of the shale is silty or sandy (Gutschick and Sandberg, 

1991).

Like the Sunbury Shale, the Bedford, Ellsworth, and 

Antrim Shales are generally not considered aquifers. The 

Bedford Shale is primarily gray shale in the Michigan Basin. 

The Bedford Shale may be greater than 213.3 ft thick in 

eastern Michigan and thins toward the center of the Michigan 

Basin (Gutschick and Sandberg, 1991). The Ellsworth Shale 

is composed of a gray to greenish‐gray shale. Ellsworth Shale 

generally contains some dolomite and may also be composed 

of sandstone and siltstone layers (Matthews, 1993). The 

Antrim Shale is composed of primarily carbonaceous, black to 

dark‐gray shale. Near the base of the sequence, thin layers of 

gray shale and limestone may occur. The major constituents of 

the Antrim Shale consist of quartz, illite, and kerogen. Kaolin‐

ite, chlorite, and pyrite also compose the Antrim Shale. The 

Antrim Shale has been found to have bituminous limestone 

concretions up to 3 ft in diameter (Matthews, 1993). The Ant‐

rim Shale can be up to 656 ft thick, which occurs at the center 

of the Michigan Basin (Gutschick and Sandberg, 1991).

The Traverse Group primarily consists of fossiliferous 

limestone. In the western portion of the basin, porous dolo‐

mite and anhydrite may be present. In the eastern portion of 

the basin, interlayers of shale are common. (Gardner, 1974). 

Nearby in Charlevoix County, the transmissivity of the lime‐

stone ranges from 13.4 to 5,347.2 ft2/day (Cathcart, 1982). 

The basal formation of the Traverse Group is the Bell Shale. 

Bell Shale has a maximum thickness of 80 ft (Catacosinos and 

others, 2001).

Arenac County

Arenac County is in the eastern north‐central portion of 

the Lower Peninsula of Michigan. The eastern portion of the 

county borders Saginaw Bay. The county is considered part of 

the Saginaw Lowlands (Westjohn and Weaver, 1998). The Au 

Gres-Rifle, Kawkawlin-Pine, Tittabawassee, and Lake Huron 

watersheds drain the county. According to the February 2005 

Wellogic database, approximately 41 percent of the wells in 

Arenac County are completed in the glacial deposits, and 56 

percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 3 percent of the wells in the 

county.

 Summary of Hydrogeologic Conditions by County for the State of Michigan
In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). The thickness of glacial deposits 

in Arenac County ranges from 0 ft in the west to 400 ft in the 

northwest (Western Michigan University, 1981). The glacial 

deposits in Arenac County are composed of primarily basal 

lodgement till and lacustrine deposits (Westjohn and Weaver, 

1994). Sand and gravel lacustrine deposits are primarily in 

the central and northern parts of the county, while clay and 

silt-lacustrine deposits are common in the southern and eastern 

parts of the county (Farrand and Bell, 1982). Moraines are 

also present in Arenac County. The Port Huron Moraine trends 

northeastward, from the southwestern corner of the county into 

Clayton and Mason Townships. Moraines are also present in 

the northeastern portion of Whitney Township, the northwest 

portion of Moffat Township, and the northwestern most corner 

of the county. The till comprising the moraines is generally 

composed of boulder‐rich clay, with areas of sand (Pringle, 

1937). According to the Public Water Supply database, glacial 

wells in Arenac County have estimated transmissivities from 

aquifer tests that range from 495 to 3,450 ft2/day.

Bedrock underlies the glacial deposits, except where bed‐

rock outcrops are present (Pringle, 1937). The bedrock surface 

of Arenac County is composed of the Saginaw Formation, 

Bayport Limestone, Michigan Formation, Marshall Sandstone, 

and Coldwater Shale (Milstein, 1987). Bedrock generally 

dips to the southwest (Pringle, 1937). According to the Public 

Water Supply database the estimated transmissivity from aqui‐

fer tests for a bedrock well in Arenac County was 136 ft2/day.

 In Arenac County, the thickness of the Saginaw Forma‐

tion ranges from 90 ft, near Rifle River, and increases to the 

southwest to Adams Township, where it is greater than 250 ft 

(Pringle, 1937). Interbedded sandstone, siltstone, shale, coal, 

and limestone compose the Saginaw Formation The Saginaw 

aquifer consists of hydraulically‐connected sandstones in the 

Saginaw Formation (Westjohn and Weaver, 1998). Within the 

State, the Saginaw aquifer ranges from less than 100 to 370 ft 

thick. The Saginaw aquifer yields fresh and saline water in the 

southwest and southeast portions of Arenac County, respec‐

tively (Westjohn and Weaver, 1996c). The Saginaw confining 

unit underlies the Saginaw aquifer. The Saginaw confining 

unit ranges from less than 100 to 240 ft thick within the State, 

and is mostly shale, with thin layers of discontinuous sand‐

stone, siltstone, limestone, and coal. The permeable layers 

within the Saginaw confining unit appear to be isolated from 

the regional ground‐water‐flow system (Westjohn and Weaver, 

1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma-Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone (Cohee 

and others, 1951). In some areas in Arenac County, the Parma 

Sandstone is completely eroded; however, where the Parma 

Sandstone is present, it ranges in thickness from 30 to 50 ft 

(Pringle, 1937). The Bayport Limestone is a fossiliferous, 

cherty limestone, often with interbedded sandstone and var‐

ies considerably in thickness from one area to another. The 

Bayport Limestone and Parma Sandstone appear to interfin‐

ger throughout the Michigan Basin (Westjohn and Weaver, 

1996a). These units are hydraulically connected, and together 

they form the Parma-Bayport aquifer (Westjohn and Weaver, 

1996a). The Parma-Bayport aquifer is approximately 100 

to 150 ft thick within the Michigan Basin. Please note that 

due to the uncertainty of stratigraphic relationship between 

these units, in other reports this aquifer may be delineated 

differently. The Parma-Bayport aquifer yields saline water in 

Arenac County (Westjohn and Weaver, 1996c).

Underlying the Bayport Limestone is the Michigan 

Formation. The Michigan Formation consists of layers of 

clay‐rich, fine‐grained sandstone, siltstone, anhydrite or gyp‐

sum, dolomite, limestone, and shale (Pringle, 1937; Westjohn 

and Weaver, 1996b). The Michigan Formation ranges from 

30 to 260 ft thick in the county. However, generally in Arenac 

County, the Michigan Formation is less than 100 ft thick (Prin‐

gle, 1937). The lower permeability lithologies of the Michigan 

Formation are considered a confining unit that separates the 

Parma-Bayport aquifer from the underlying Marshall aquifer 

(Westjohn and Weaver, 1996b).

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone consists of one or more strati‐

graphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member (Westjohn and Weaver, 

1998). In Arenac County, the Napoleon Sandstone Member 

varies from 100 to 270 ft thick (Pringle, 1937). A shale, silt‐

stone, and/or carbonate layer separates the Napoleon Sand‐

stone Member from the lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units, which com‐

bined range from 70 to 250 ft in thickness in Arenac County 

(Pringle, 1937; Westjohn and Weaver, 1998). The upper unit is 

generally 50 to 125 ft of fine‐ to medium‐grained quartzarenite 

to sublitharenite. The basal unit is a fine‐ to medium‐grained 

litharenite that ranges in thickness from 30 to 125 ft. Per‐

meable sandstones in the Marshall Sandstone comprise the 

Marshall aquifer. The Marshall aquifer ranges in thickness 

from 75 to greater than 200 ft within the State (Westjohn and 

Weaver, 1998). The Marshall aquifer is capable of supplying 

large quantities of water. The Marshall aquifer yields mostly 

saline water in Arenac County, except for an area in the north‐

ern portion of the county, where the aquifer yields fresh water 

(Westjohn and Weaver, 1996c).

The Coldwater Shale underlies the Marshall Sandstone, 

and consists of primarily blue and gray shale with interbeds, 

or lenses, of sandstone, siltstone, and dolomite (Pringle, 1937; 

Westjohn and Weaver, 1996b). The Coldwater Shale is rela‐

County Summaries 
tively impermeable and is considered a confining unit in most 

of Michigan (Westjohn and Weaver, 1996b).

Baraga County

Baraga County is in the western portion of the Upper 

Peninsula of Michigan. Sturgeon, Dead-Kelsey, Lake Supe‐

rior, Brule, and Michigamme watersheds can be found in the 

county. According to the February 2005 Wellogic database, 

approximately 17 percent of the wells in Baraga County 

are completed in the glacial deposits, and 75 percent in the 

bedrock units. There is insufficient information to make this 

distinction for 8 percent of the wells in the county. Most wells 

in the county only produce small yields suitable for domestic 

use. Doonan and Byerlay (1973) identify a layer of swamp 

deposits and Holocene alluvium, the glacial aquifer, and three 

bedrock aquifers: the Jacobsville Sandstone, the Marquette 

Range Supergroup, and Laurentian granite and gneiss. It is not 

clear which aquifers are confined or unconfined.

Swamp deposits, consisting of muck and silt, and Holo‐

cene alluvium are concentrated in the northwestern portion of 

the county and also occur sporadically in patches. Small yields 

of water are possible from the swamp deposits and Holocene 

alluvium, but may be high in iron concentrations (Doonan and 

Byerlay, 1973).

 Aquifers in the glacial deposits consist largely of sands 

and gravels, and vary regionally in thickness and permeabil‐

ity. Glacial deposits are composed of till, outwash, stream 

deposits, and lacustrine deposits. Unstratified glacial depos‐

its include sandy to clayey till in moraines and till plains. 

Stratified deposits that are composed of till include: kames, 

kame terraces, and eskers. Other stratified glacial deposits are 

sand and gravel outwash, stream deposits, and clay and sand 

lacustrine deposits. Three major moraines have been identi‐

fied in Baraga County. The Keweenaw Moraine lies along 

the Keweenaw Bay. The Marenisco Moraine is located in the 

southern portion of the county. The Covington Moraine trends 

northeast from the Marenisco Moraine, near Covington. Small 

to moderate yields of water may be obtained from moraines. 

Outwash deposits are dispersed throughout the county and are 

often covered by postglacial deposits. However, the largest 

area of outwash in the county is located near the Keweenaw 

Moraine and is partially overlain by lacustrine deposits. In 

the west‐central portion of the county, is the largest lacustrine 

deposit. This deposit is up to 200 ft thick. Lacustrine depos‐

its yield moderate supplies of water in Baraga County. The 

transmissivity of the glacial aquifer was calculated using the 

specific capacity values of Doonan and Byerlay (1973) and 

ranges from 20 to 3,948 ft2/day. Ground‐water supplies from 

the glacial aquifer tend to be high in iron, and occasionally 

have a low pH. The water ranges from soft to very hard and 

may be high in iron content. (Doonan and Byerlay, 1973).

Bedrock underlies glacial deposits, where glacial deposits 

are present. In areas where glacial deposits are absent or 

thin, water must be obtained from the bedrock aquifers. The 

transmissivity of the bedrock aquifers was calculated using 

the specific capacity values of Doonan and Byerlay (1973) 

and ranges from 1 to 600 ft2/day. About half the bedrock wells 

in Baraga County acquire water from the Jacobsville Sand‐

stone. Water from the Jacobsville Sandstone ranges from soft 

to very hard and iron concentration varies. Small amounts of 

water are obtained from fractures within the upper portion of 

the Marquette Range Supergroup. Water from the Marquette 

Range Supergroup is usually moderately hard to very hard. 

Laurentian granite and gneiss may also provide small yields of 

water from fractures. However, the water is hard and contains 

iron (Doonan and Byerlay, 1973).

Barry County

Barry County is in the southwestern Lower Peninsula of 

Michigan. The Thornapple and Kalamazoo watersheds drain 

the county. According to the February 2005 Wellogic database, 

approximately 88 percent of the wells in Barry County are 

completed in the glacial deposits, and 9 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 3 percent of the wells in the county. The Marshall aquifer 

is the primary bedrock aquifer in the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). The glacial deposits in Barry County range in 

thickness from 150 to 400 ft (Lilienthal, 1974). Glacial depos‐

its in the county include till, outwash, and lacustrine deposits. 

End moraines in the county are the result of the retreat of 

the Lake Michigan and Saginaw Lobes of the Laurentide Ice 

Sheet. The moraines present from the Lake Michigan Lobe 

occur in the west and southwestern portions of the county, 

and trend generally southwest to northeast. This moraine is 

predominantly poorly‐sorted, coarse‐grained till, composed of 

sand and gravel, and has stony, boulder‐rich till interbedded. 

The moraines formed from the Saginaw Lobe trend gener‐

ally from the northeast to southwest and are located in the 

northwestern, central, and eastern portion of the county. These 

moraines are composed of poorly sorted, coarse deposits that 

fine toward the till plains. Till plains are located in the north‐

ern and eastern parts of Barry County, and consist of loamy, 

clayey‐till. Outwash is located throughout the county. Outwash 

is composed of primarily well‐sorted, sand and gravel. Lacus‐

trine clay is dispersed throughout the outwash (Brewer, 1991).

Glacial aquifers consist of sand and gravel that are part 

of a thick sequence of glacial deposits (Westjohn and others, 

1994). In Barry County, the glacial aquifer consists of primar‐

ily outwash and morainal deposits. According to the Public 

Water Supply database, the estimated transmissivity for glacial 

wells on the outwash plains in the county range from approxi‐

mately 12,205 to 31,250 ft2/day. It is common for glacial wells 

to have high levels of chloride and nitrate in Barry County 

(Brewer, 1991).

 Summary of Hydrogeologic Conditions by County for the State of Michigan
Bedrock underlies the glacial deposits. The bedrock 

dips to the northeast. The bedrock surface includes, generally 

from northeast to southwest, the Saginaw Formation, Bay‐

port Limestone, Michigan Formation, Marshall Sandstone, 

and Coldwater Shale. The Saginaw Formation is composed 

of sandstone, siltstone, shale, limestone, and coal. Sandstone 

with layers of shaly sand, sandy shale, and shale predominate 

the Saginaw Formation in Barry County. In the county, the 

Saginaw Formation is approximately 50 ft thick (Lilienthal, 

1974). The Saginaw Formation is not an important source of 

water in Barry County.

 The Parma Sandstone is often considered the basal unit 

of the Saginaw Formation, although the stratigraphic rela‐

tionship is not clear between the Saginaw Formation, Parma 

Sandstone, and Mississippian‐aged Bayport Limestone. The 

Parma Sandstone is composed of medium‐ to coarse‐grained 

sandstone, and is generally less than 100 ft thick (Cohee and 

others, 1951). The Bayport Limestone is a fossiliferous, cherty 

limestone, often with interbedded sandstone. The Bayport 

Limestone has maximum thickness of 50 ft in the county and 

thins to the south, southwest, and west (Lilienthal, 1974). The 

Bayport Limestone and Parma Sandstone appear to interfin‐

ger throughout the Michigan Basin (Westjohn and Weaver, 

1996a). Locally, both the Parma Sandstone and Bayport 

Limestone have been highly eroded (Lilienthal, 1974). These 

units are hydraulically connected, and together they form 

the Parma-Bayport aquifer (Westjohn and Weaver, 1996a). 

Please note that due to the uncertainty of stratigraphic relation‐

ship between these units, in other reports this aquifer may be 

delineated differently. The Parma-Bayport aquifer only occurs 

in the northeastern most edge of Barry County, and is 50 ft or 

less in thickness (Westjohn and Weaver, 1996a). It is not an 

important aquifer in the county.

The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation is composed of sandstone, 

shale, limestone, and occasional dolomite, which are all gener‐

ally low in permeability. Gypsum and anhydrite are present in 

the Michigan Formation. The Michigan Formation is consid‐

ered a confining unit that separates the Parma-Bayport aquifer 

from the underlying Marshall aquifer. In Barry County, the 

Michigan Formation ranges from 150 to 200 ft thick (Lilien‐

thal, 1974). In Barry County, some wells have been screened 

in the Michigan Formation. The water in these wells may yield 

high calcium and sulfate concentrations (Brewer, 1991).

The Marshall Sandstone underlies the Michigan Forma‐

tion and is 350 to 400 ft thick in Barry County (Lilienthal, 

1974). The Marshall Sandstone consists of one or more 

stratigraphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzare‐

nite to sublitharenite. At the base of the Marshall Sandstone is 

a fine‐ to medium‐grained litharenite that ranges in thickness 

from 30 to 125 ft. Permeable sandstones in the Marshall Sand‐

stone comprise the Marshall aquifer. The Marshall aquifer 

ranges in thickness from 75 to greater than 200 ft within the 

State (Westjohn and Weaver, 1998). The Marshall aquifer is 

the primary bedrock aquifer in Barry County (Brewer, 1991). 

According to the Public Water Supply database, the estimated 

transmissivity for wells in the Marshall aquifer in Barry 

County ranges from approximately 310 to 38,100 ft2/day. 

In Barry County, the upper portion of the Marshall aquifer 

may yield fresh water, while the lower portion of the aquifer 

may yield saline water or brine (Simms, 1988). Westjohn and 

Weaver (1996c) found the Marshall aquifer to supply fresh 

water in the majority of the county, excluding an area in the 

northeast portion of the county where the water is saline.

The Coldwater Shale underlies the Marshall Sandstone. 

Calcareous shale, with interbeds of silty shale, and thin sand‐

stone comprise the Coldwater Shale in Barry County (Lilien‐

thal, 1974). In the western portion of the State, the Coldwater 

Shale contains more carbonate than siltstone or sandstone 

(Monnett, 1948). The Coldwater Shale is generally considered 

a confining unit and ranges in thickness, from 500 to 1,300 ft, 

east to west across the State (Westjohn and Weaver, 1996b).

Bay County

Bay County is in the eastern‐central portion of the Lower 

Peninsula of Michigan. The county is considered part of the 

Saginaw Lowlands (Westjohn and Weaver, 1998). Bay County 

borders Saginaw Bay along a portion of its eastern side. The 

Kawkalin-Pine, Pigeon-Wiscoggin, Tittabawasse, Saginaw, 

and Lake Huron watersheds are included in the county on the 

north and central, southeast, northwest and southwest corners, 

south‐central, and eastern portions of the county, respectively. 

The availability of ground water is a problem in areas of the 

county, due to low yields and mineral concentrations. Accord‐

ing to the February 2005 Wellogic database, approximately 

37 percent of the wells in Bay County are completed in the 

glacial deposits, and 59 percent in the bedrock units. There is 

insufficient information to make this distinction for 4 percent 

of the wells in the county. Glacial sand and gravel deposits, 

and sandstone from the Saginaw Formation form the two prin‐

cipal aquifers in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a sequence of Pleistocene glacial 

deposits. With the available information, glacial lithologies 

cannot be regionally correlated in the subsurface. This is likely 

due to the lateral and vertical heterogeneity of glacial deposits 

that resulted from a complex depositional history (Westjohn 

and others, 1994). Glacial deposits are up to 200 ft thick in 

Bay County (Western Michigan University, 1981). In the 

southern portion of the county, the greatest thickness of glacial 

deposits is found in buried valleys. The buried valleys trend 

northeast to southwest across Williams, Monitor, and Franken‐

lust Townships, and southeast to northwest in Merritt Town‐

ship (Twenter and Cummings, 1985). Glacial deposits present 

County Summaries 
in the county include lacustrine deposits and till. Lacustrine 

deposits consist of clay and silt‐dominated deposits, and also 

sand and gravel‐dominated deposits. Fine to medium‐grained 

till is also present in the county (Farrand and Bell, 1982). In 

the southern portion of the county, generally, the uppermost 50 

to 150 ft of glacial deposits are composed of clay. Locally, the 

clay may extend to the bedrock surface, contain thin interbeds 

of silt and fine‐grained sand, or contain thin to 60 ft thick lay‐

ers of sand and gravel. Wells tapping clay deposits supply very 

little, if any, water. In areas of the central‐eastern and south‐

eastern of Williams Township, and in northeastern, northwest‐

ern, and central‐western parts of Monitor Township, sand and 

gravel deposits are large and thick enough to be considered an 

aquifer (Twenter and Cummings, 1985). In Garfield Township, 

Stark and McDonald (1980) divided the glacial deposits into 

three units: sand, clay, and sand and gravel. The uppermost 

unit is composed of proglacial, well‐sorted sand. The sand 

unit ranges in thickness from 0 to 20 ft, and occurs in narrow 

ridges across the surface of the area. The clay unit is underlies 

the sand unit and ranges in thickness from 30 to 164 ft. The 

clay unit is predominately silt and clay, but also includes sand, 

gravel, and a clay and gravel mixture. Underlying the clay 

unit, is the sand and gravel unit, which ranges in thickness 

from 0 to 131 ft. The sand and gravel unit consists of predomi‐

nately sand, gravel, and pebbles, but also consists of a minor 

amount of silt and clay. The sand and gravel unit is under 

confined conditions (Stark and McDonald, 1980) and gener‐

ally yields potable water (Twenter and Cummings, 1985). 

However, water from some glacial wells have been reported to 

be salty (Twenter and Cummings, 1985).

The Saginaw Formation underlies the glacial deposits and 

forms the bedrock surface in Bay County. The Saginaw For‐

mation is, on average, 330 ft thick, and composed of primarily 

shale, sandstone, and coal and may contain siltstone and lime‐

stone. The most abundant unit in this sequence varies locally. 

The beds are often discontinuous (Twenter and Cummings, 

1985). In a study area located in Garfield Township, the upper‐

most portion of the Saginaw Formation is an upper shale unit. 

This unit is composed of two types of shale: hard fissile shale 

with carbonaceous deposits and pyrite, and massive, soft silty 

shale. The upper shale unit also contains thin layers of coal, 

sandstone, and siltstone. The main coal unit has an average 

thickness of 1.6 ft. In one area of Bay County, up to three beds 

of coal are present. Underneath the coal is the lower shale 

unit. This unit is primarily shale with thin layers of quartz‐rich 

sandstone (Stark and McDonald, 1980). The Saginaw aquifer 

is comprised of the permeable beds of sandstone within the 

Saginaw Formation (Westjohn and Weaver, 1996a). Sand‐

stone occurs at the base of the formation and is the principal 

bedrock aquifer. The sandstone is generally quartz‐rich, well 

sorted, and fine‐grained and may have thin beds of shale or 

clay in areas (Stark and McDonald, 1980). According to Stark 

and McDonald (1980), transmissivity values for this layer 

are between 300 to 380 ft2/day, and the storage coefficient 

is 0.0001. According to the Public Water Supply database, 

the estimated transmissivity from aquifer tests for the Sagi‐

naw aquifer in Tuscola County is 2,540 ft2/day. Water from 

the Saginaw aquifer may be locally high in dissolved solids 

(Twenter and Cummings, 1985). In Bay County, the Saginaw 

aquifer only yields freshwater in the northwestern portion of 

the county (Westjohn and Weaver, 1996c).

The Saginaw confining unit underlies the Saginaw aqui‐

fer. The Saginaw confining unit is approximately 50 to 100 

ft thick in the county, and is mostly shale, with thin layers of 

discontinuous sandstone, siltstone, limestone, and coal. The 

permeable layers within the Saginaw confining unit appear to 

be isolated from the regional ground‐water‐flow system (West‐

john and Weaver, 1996a).

Benzie County

Benzie County is in the northwestern portion of the 

Lower Peninsula of Michigan. Sleeping Bear Dunes National 

Lakeshore is in the northwestern portion of the county. The 

Manistee, Betsie-Platte, and Lake Michigan watersheds drain 

the county. According to the February 2005 Wellogic data‐

base, approximately 97 percent of the wells in Benzie County 

are completed in the glacial deposits, and 0 percent in the 

bedrock units. There is insufficient information to make this 

distinction for 3 percent of the wells in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional his‐

tory (Westjohn and others, 1994). Glacial deposits in Benzie 

County range from 401 to 1,000 ft in thickness. However, 

the majority of the glacial deposits are between 401 and 800 

ft thick (Western Michigan University, 1981). In Sleeping 

Bear Dunes National Lakeshore, the glacial deposits range 

from 700 to 900 ft thick (Handy and Stark, 1984). The glacial 

deposits in the county include outwash, till and lacustrine 

deposits. The outwash deposits are mainly composed of sand 

and gravel. The majority of the outwash deposits occur in the 

central and eastern portions of the county (Farrand and Bell, 

1982). Till deposits are generally a poorly sorted mixture of 

clay, silt, sand, gravel, and rock fragments (Handy and Stark, 

1984), which are generally found in moraines and till plains. 

In Benzie County, the till is medium to coarse grained (Far‐

rand and Bell, 1982). Moraines are present in the western and 

southeastern portions of the county. Glacial wells in Benzie 

County completed in till and/or outwash, according to the 

Public Water Supply database, have estimated transmissivi‐

ties from aquifer tests that range from approximately 1,280 

to 64,940 ft2/day. The lacustrine deposits are coarse‐grained 

and occur in areas in the southeastern and western portions of 

the county (Farrand and Bell, 1982). According to the Public 

Water Supply database, a well completed in lacustrine deposits 

in the county had an estimated transmissivity from an aquifer 

test of approximately 619 ft2/day.

10 Summary of Hydrogeologic Conditions by County for the State of Michigan
 In Sleeping Bear Dunes National Lakeshore, specific 

capacity ranges from less than 1 and 50 gal/min/ft. Handy and 

Stark (1984) have identified areas of high specific capacity in 

glacial wells at and near Sleeping Bear Dunes National Lake‐

shore. In Benzie County, this includes an area northeast of 

Otter Lake. A specific capacity test was conducted near Loon 

Lake and values were determined to be 7.5 and 8.5 gal/min/ft 

(Handy and Stark, 1984).

Berrien County

Berrien County is located along the shore of Lake 

Michigan in the southwestern portion of the Lower Peninsula. 

In addition to Lake Michigan, the Little Calumet-Galien, 

St. Joseph, Black-Macatawa, and Kankakee watersheds are 

included in the county. Glacial aquifers are the primary source 

of ground water in Berrien County. In general, the glacial 

aquifer is unconfined, except where clay‐rich, glacial‐lake 

deposits act as a confining layer. According to the February 

2005 Wellogic database, approximately 99 percent of the 

5,260 water well logs in Berrien County are completed in the 

glacial deposits, and less than 1 percent in the bedrock units. 

There is insufficient lithologic information to make this dis‐

tinction for 4 percent of the water well logs in the county.

Post‐glacial deposits in Berrien County consist of eolian 

deposits, lacustrine deposits, and alluvium. Eolian deposits 

consist of primarily dune sand along the Lake Michigan Shore 

(Stone, 2001). Alluvium is composed of sand and gravel and 

has a limited extent.

The thickness of glacial deposits varies within the county 

and does not always correlate beneath the surface. Glacial 

deposits in Berrien County include deposits forming the Lake 

Border and Valparaiso moraines and range in thickness from 

40 to 400 ft (Leverett and Taylor, 1915; Bayless and others, 

2005). Leverett and Taylor (1915), state that the Valparaiso 

moraine contains more sand and gravel in Michigan compared 

to the till‐rich composition found in Indiana and Illinois. 

Geologists from the Great Lakes Geologic Mapping Coalition 

(Bayless and others, 2005) describe the Valparaiso moraine 

in Berrien County as a series of interleaved glaciodeltas 

deposited as the glaciers retreated from the area. In places the 

deltas are capped by thick clay‐rich till or lake‐bed deposits. 

In the northern portion of the county, a more collapsed terrain, 

referred to as the Sodus terrain, with more kettle holes and 

“swell and swale” morphology is evident. The Lake Border 

moraine south of Benton Harbor is characterized by silty till 

containing some small layers of fine to medium sand. The till 

generally is not an aquifer, but some water may be obtained 

from the sand layers for domestic use. Northeast of Benton 

Harbor, a terrace terrain, referred to as the Paw Paw terrain, 

has an outwash sand aquifer that is overlain by a silty till. In 

areas the sand aquifer is fairly extensive and may be under 

artesian conditions. According to the Public Water Supply 

database, the estimated transmissivity for glacial wells in 

Berrien County ranges from approximately 3,125 to 23,590 

ft2/day.

Glacial deposits overlie the bedrock. The bedrock surface 

is composed of the Coldwater Shale. The Coldwater Shale is 

from 300 to 600 ft thick in Berrien County, and consists of 

primarily shale with some limestone. The Coldwater Shale 

generally yields small quantities of water that may be saline, 

generally from the limestone in the unit (Stuart and Stallman, 

1945).

Branch County

Branch County is an area of 506 mi2 in the southern 

Lower Peninsula of Michigan. The St. Joseph watershed 

drains the county. The topography ranges from flat till plains 

to rolling hills (Giroux and others, 1966). According to the 

February 2005 Wellogic database, approximately 83 percent 

of the wells in Branch County are completed in the glacial 

deposits, and 13 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 4 percent of the 

wells in the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). The glacial deposits are up to 500 ft thick in 

the county. Both the Erie and Saginaw lobes covered Branch 

County during glacial times. The glacial deposits from the 

Erie lobe, located in the southern portion of the county, are 

composed of fragments of limestone and other sedimen‐

tary rocks. The northern part of the county contains glacial 

deposits from the Saginaw lobe, and is composed of remnants 

of granites and other hard rocks. Glacial deposits include till, 

outwash, and lacustrine deposits. Silty, clayey soils overlie the 

till deposits (Giroux and others, 1966). The till in the county 

is medium to coarse grained (Farrand and Bell, 1982). Till 

occurs in moraines and till plains. The morainal till is com‐

posed of boulders, gravel, and sand in a clay and silt matrix, 

and contains local lenses of outwash. The till in till plains 

often has a higher amount of clay than the till in the moraines 

and does not contain lenses of outwash. Outwash deposits in 

the county are overlain by well‐drained, sandy soils. Outwash 

consists of sand and gravel. Lakes in the county are generally 

surrounded by outwash deposits. The lacustrine deposits are 

composed of muck, silt, and clay, and are not considered to be 

aquifer material (Giroux and others, 1966).

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of glacial deposits 

(Westjohn and others, 1994). Wells that are completed in the 

lenses of outwash within the till yield 10 to 40 gal/min and 

provide moderate supplies of water. While, wells completed 

in till plains generally supply small quantities of water, with 

yields from 0 to 15 gal/min. Wells in the outwash deposits 

supply moderate to large amounts of water, with yields up to 

5,000 gal/min (Giroux and others, 1966). According to the 

County Summaries 11
Public Water Supply database, the estimated transmissivity for 

sand and gravel glacial wells in Branch County ranges from 

approximately 590 to 38,700 ft2/day. The glacial aquifer may 

yield water that is hard and contains high iron concentrations 

(Giroux and others, 1966).

Bedrock underlies the glacial deposits. The Coldwa‐

ter Shale forms the bedrock surface in Branch County. The 

thickness of the Coldwater Shale ranges from 440 to 1,000 

ft in the county. The Coldwater Shale is predominately blue 

to gray shale and interbedded with thin lenses of limestone, 

dolomite, and sandstone (Giroux and others, 1966). The 

Coldwater Shale is considered a confining unit in the majority 

of the State (Westjohn and Weaver, 1998). In Branch County, 

however, wells are locally completed in the Coldwater Shale. 

These wells generally provide small quantities of water, from 

the lenses of sandstone or limestone, or from fractures. Yields 

from these wells range from 2 to 3 gal/min to 10 to 30 gal/min. 

The water from the Coldwater Shale is often salty (Giroux and 

others, 1966).

Calhoun County

Calhoun County is in the southern portion of the Lower 

Peninsula of Michigan. The Upper Grand, Kalamazoo, and 

St. Joseph watersheds drain the county in the northeastern, 

central, and southwestern portions of the county. According 

to the February 2005 Wellogic database, approximately 36 

percent of the wells in Calhoun County are completed in the 

glacial deposits, and 58 percent in the bedrock units. There is 

insufficient information to make this distinction for 6 percent 

of the wells in the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). Glacial deposits are up to 400 ft thick in the 

county (Western Michigan University, 1981). Glacial deposits 

in Calhoun County include channel deposits, outwash, and 

till. Alluvium and glacial‐stream deposits that are intercon‐

nected are referred to as channel deposits. The thickness of 

channel deposits in the Verona well field area ranges from 5 

to 37 ft. Channel deposits are generally coarser than outwash 

(Grannemann and Twenter, 1985). Sand and gravel outwash 

is abundant and interspersed throughout Calhoun County. 

Although fine to coarse sand is found in the outwash deposits 

at the Verona well field, most of the sand deposits in this area 

are medium‐grained and coarser. The thickness of outwash 

deposits varies in the county. In the Verona well field, the 

maximum thickness of outwash is 100 ft. The majority of the 

till in the county is medium to coarse grained (Grannemann 

and Twenter, 1985; Farrand and Bell, 1982). Till is a mixture 

of clay, silt, sand, gravel, and boulders. Till occurs in till plains 

and moraines in Calhoun County. Moraines in the county 

generally trend northwest to southeast and include the Kalam‐

azoo Moraine, Battle Creek Moraine, and Tekonsha Moraine 

(Vanlier, 1966). The thickness of till varies in the county. Till 

is thickest in morainal areas. For example, till is up to 125 ft 

thick in the Verona well field area, located in Battle Creek, 

in a portion of the Kalamazoo Moraine. Thin layers of till 

may underlie outwash deposits (Grannemann and Twenter, 

1985). The Tekonsha Moraine consists of primarily sandy 

till that also contains thin clay layers and discontinuous areas 

of sand and gravel (Chowdhury, 1999). Clay deposits and 

sandy‐silty‐clay deposits have also been found in wells at the 

Verona well field (Grannemann and Twenter, 1985).

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of glacial deposits. 

In Calhoun County, the glacial aquifer consists of primarily 

outwash and morainal deposits (Westjohn and others, 1994). 

The estimated hydraulic conductivities in Calhoun County 

are 110, 70, 30, and 15 ft/day for channel deposits, outwash, 

interlayered outwash and till, respectively (Grannemann and 

Twenter, 1985). According to the Public Water Supply data‐

base, the estimated transmissivity for glacial wells in Calhoun 

County ranges from approximately 3,210 to 13,500 ft2/day. 

Water from the glacial aquifer is generally hard to very hard 

and may contain excessive iron concentrations (Vanlier, 1966).

 Bedrock underlies the glacial deposits, and the bedrock 

surface of Calhoun County includes, from northeast to south‐

west, the Saginaw Formation, Bayport Limestone, Michigan 

Formation, Marshall Sandstone, and Coldwater Shale. The 

bedrock units have a slight dip to the northeast (Vanlier, 1966). 

The Saginaw Formation consists of sandstone, shale, coal, 

and limestone. The most abundant unit in this sequence var‐

ies locally. The Saginaw Formation yields more water from 

sandstone at shallow depths and from thicker sandstone units 

(Vanlier, 1966). The Saginaw aquifer is comprised of the sand‐

stones from the Saginaw Formation and ranges in thickness 

from less than 100 to 370 ft in thickness in the State (Westjohn 

and Weaver, 1996a). In Calhoun County, the Saginaw aquifer 

occurs in the northeastern corner of the county and the water 

is fresh (Westjohn and Weaver, 1996c). The Saginaw confin‐

ing unit underlies the Saginaw aquifer, and is composed of 

primarily shale, but also contains beds of sandstone, siltstone, 

coal, and limestone. The permeable layers within the Sagi‐

naw confining unit appear to be isolated from the regional 

ground‐water‐flow system (Westjohn and Weaver, 1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma-Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably 

in thickness from one area to another. The Bayport Lime‐

stone and Parma Sandstone appear to interfinger throughout 

the Michigan Basin (Westjohn and Weaver, 1996a). These 

units are hydraulically connected, and together they form the 

12  Summary of Hydrogeologic Conditions by County for the State of Michigan
Parma-Bayport aquifer (Westjohn and Weaver, 1996a). The 

Parma-Bayport aquifer is generally 100 to 150 ft thick where 

it occurs within the Michigan Basin. Please note that due to 

the uncertainty of stratigraphic relationship between these 

units, in other reports this aquifer may be delineated differ‐

ently. According to Vanlier (1966), the Parma-Bayport aquifer 

yields fresh water and may locally provide moderate water 

supplies where it is thick and solution cavities are present in 

the limestone.

The Michigan Formation underlies the Bayport Lime‐

stone, and is composed of sandstone, siltstone, shale, lime‐

stone, and occasionally dolomite. Gypsum and anhydrite are 

also present in the Michigan Formation. Siltstone and sand‐

stone layers that are discontinuous and interposed with lower 

permeability lithologies are considered the Michigan confin‐

ing unit. The Michigan confining unit separates the ParmaBayport aquifer from the underlying Marshall aquifer. In the 

county, the Michigan confining unit is approximately 100 ft 

thick (Westjohn and Weaver, 1996b).

The Marshall Sandstone underlies the Michigan For‐

mation. The Marshall Sandstone is predominately a fine to 

coarse‐grained sandstone with interbeds of siltstone, sandy 

shale, and shale. In general, grain size decreases with depth 

in the Marshall Sandstone. Due to differential erosion, the 

thickness of the Marshall Sandstone ranges from 0 to 200 ft 

in the Verona well field area. In the same area, the Marshall 

Sandstone has been divided into the upper sandstone, upper 

siltstone, lower sandstone, lower siltstone, and shale. The 

upper sandstone, often referred to as the Napoleon Sandstone 

Member, is considered to be an unconfined aquifer in areas, 

and is underlain by the upper siltstone that acts as a confining 

layer. Below the upper siltstone is the lower sandstone and 

underlying lower siltstone, which form the lower confined 

aquifer in the Marshall Sandstone. Shale underlies this lower 

confined aquifer.

 Aquifer tests were performed on wells that obtain water 

from both the upper and lower portions of the Marshall Sand‐

stone at the Verona well field and the transmissivities ranged 

from 4,200 to 64,400 ft2/day (Lynch and Grannemann, 1997). 

A pumping test was performed on the upper sandstone aquifer 

and a transmissivity of 320 ft2/day was estimated. A range of 

transmissivity values, 0 to 15,000 ft2/day, were estimated for 

the upper sandstone aquifer from a constant hydraulic con‐

ductivity (150 ft/d) and thickness from 0 to 100 ft. A pumping 

test was performed on the lower sandstone aquifer, and the 

transmissivity and storage coefficient was estimated at 25,000 

ft2/day and 1.5 x 10‐5, respectively. A range of transmissivity 

values, 3,000 to 27,000 ft2/day, were estimated for the lower 

sandstone aquifer from a constant hydraulic conductivity (550 

ft/d) and thickness from 5 to 50 ft (Grannemann and Twenter, 

1985). The Marshall aquifer yields fresh water in Calhoun 

County (Westjohn and Weaver, 1996c).

The Coldwater Shale underlies the Marshall Sandstone 

and is composed primarily of shale, but also includes layers 

of carbonate, siltstone, and sandstone. In the western portion 

of the State, the Coldwater Shale contains more carbonate 

than siltstone or sandstone (Monnett, 1948). The impermeable 

lithologies in the Coldwater Shale comprise the Coldwater 

confining unit. (Westjohn and Weaver, 1998).

Cass County

Cass County is in the southwestern Lower Peninsula of 

Michigan. The southern portion of the county borders Indiana. 

The county is in the St. Joseph watershed. According to the 

February 2005 Wellogic database, approximately 97 percent of 

the wells in Cass County are completed in the glacial depos‐

its, and 0 percent in the bedrock units. There is insufficient 

information to make this distinction for 3 percent of the wells 

in the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). Glacial deposits range in thickness from 100 

to 600 ft in the county, but are generally 200 to 400 ft thick 

(Western Michigan University, 1981). The surficial glacial 

deposits in Cass County are composed primarily of outwash, 

ice‐contact outwash, and till. Outwash covers most of the 

county and is composed of well‐sorted sand and gravel depos‐

its. Ice‐contact outwash, composed of poorly sorted sand and 

gravel, is also present in the county. Moraines and till plains 

consist of coarse‐grained till (Farrand and Bell, 1982).

 In the Michigan basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene gla‐

cial deposits (Westjohn and others, 1994). Kehew and others 

(1998) provide more detailed information about the east‐cen‐

tral portion of the county. In this area, the thickness of glacial 

deposits is approximately 279 ft. Here, the glacial deposits 

consist of a shallow sand and gravel aquifer that is approxi‐

mately 16 to 84 ft thick. Underneath this is an approximately 

16 to 39 ft, generally continuous, layer of silt and clay‐rich 

till. Coarse‐grained glacial deposits generally underlie the thin 

till layer in this area. Wells in the east‐central portion of Cass 

County are generally screened above or below the silt and 

clay‐rich till layer (Kehew and others, 1998). According to the 

Public Water Supply database, the estimated transmissivity for 

glacial wells in Cass County ranges from approximately 3,930 

to 13,265 ft2/day. Bedrock underlies the glacial deposits, but is 

not currently used for water supply.

Charlevoix County

Charlevoix County is in the northern Lower Peninsula. 

Included in Charlevoix County are islands located to the 

northwest in Lake Michigan. The Boardman-Charlevoix, 

Lake Michigan, and Cheboygan watersheds drain the county. 

According to the February 2005 Wellogic database, approxi‐

mately 66 percent of the wells in Charlevoix County are com‐

pleted in the glacial deposits, and 18 percent in the bedrock 

County Summaries 13
units. There is insufficient information to make this distinction 

for 16 percent of the wells in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional his‐

tory (Westjohn and others, 1994). The majority of the glacial 

deposits in Charlevoix County range from 201 to 400 ft thick. 

However, the thickness of the glacial deposits span from 11 

to 800 ft in the county (Western Michigan University, 1981). 

Glacial deposits include lacustrine, till, and outwash. Sand and 

gravel lacustrine deposits are present along the western side 

of the county. Coarse‐grained till is present in the western and 

central portions of the county. Drumlins occur on the till plains 

in the county and are composed of stony, sandy till (Mel‐

horn, 1954). Coarse‐grained end moraines are predominantly 

located on the surface of the eastern side of the county. Sand 

and gravel outwash deposits are also abundant on the surface 

of the eastern side of the county (Farrand and Bell, 1982). In 

addition, sand dunes may be found along the Lake Michigan 

shoreline in the county (Farrand and Bell, 1982). According to 

the Public Water Supply database, the estimated transmissivity 

for glacial wells ranges from approximately 3,175 to 19,670 

ft2/day.

The bedrock surface is composed of the Ellsworth Shale, 

Antrim Shale, and Traverse Group on the mainland, and the 

island bedrock surfaces are composed of the Detroit River 

Group, Bois Blanc Formation, and Garden Island Forma‐

tion (Milstein, 1987). According to the Public Water Supply 

database, the estimated transmissivity for bedrock wells ranges 

from approximately 120 to 35,700 ft2/day.

The Ellsworth Shale is composed of a gray to green‐

ish‐gray shale. Ellsworth Shale generally contains some 

dolomite and may also be composed of sandstone and siltstone 

layers (Matthews, 1993). This unit is generally not consid‐

ered an aquifer. The Antrim Shale is composed of primarily 

carbonaceous, black to dark‐gray shale. Near the base of the 

sequence, thin layers of gray shale and limestone may occur. 

The major constituents in the Antrim Shale consist of quartz, 

illite, and kerogen. Kaolinite, chlorite, and pyrite also com‐

pose the Antrim Shale. The Antrim Shale has been found to 

have bituminous limestone concretions up to 3 ft in diameter 

(Matthews, 1993). The Antrim Shale can be up to 656 ft thick, 

which occurs at the center of the Michigan Basin (Gutschick 

and Sandberg, 1991). Like the Ellsworth Shale, this unit is not 

considered an aquifer.

The underlying Traverse Group primarily consists of 

fossiliferous limestone. In the western portion of the basin, 

porous dolomite and anhydrite may be present. In the eastern 

portion of the basin, interlayers of shale are common. (Gard‐

ner, 1974). In Charlevoix County karst topography has been 

found to affect the ground‐water flow. Based on aquifer tests 

in Charlevoix County, the transmissivity of the limestone 

ranges from 13.4 to 5,347.2 ft2/day (Cathcart, 1982). The basal 

formation of the Traverse Group is Bell Shale. Bell Shale has 

a maximum thickness of 80 ft in Michigan (Catacosinos and 

others, 2001).

The Detroit River Group forms the bedrock surface of 

the southern portion of Beaver Island (Milstein, 1987). In 

the subsurface, the Detroit River Group consists of the Lucas 

Formation, Amherstburg Formation, and Sylvania Sandstone. 

The Lucas Formation is primarily composed of interlayered 

carbonates and evaporates, with carbonate‐cemented, fine‐ to 

medium‐grained, sandstone lenses are scattered near the basal 

portion of the formation. The Lucas Formation is up to 1,050 

ft in thickness in the Michigan Basin. In some areas, the water 

from this formation is brine and may contain hydrogen sulfide. 

The Amherstburg Formation underlies the Lucas Forma‐

tion. The Amherstburg Formation is up to 300 ft thick and 

is composed of fossiliferous limestone that is dolomitized in 

some areas. An upper sandstone is present in the formation 

in the western portion of the basin. The Sylvania Sandstone 

underlies the Amherstburg Formation. The Sylvania Sandstone 

is composed of fine‐ to medium‐grained sandstone with quartz 

overgrowths interlayered with carbonate. Sylvania Sandstone 

has been eroded in areas of the basin (Gardner, 1974).

The Bois Blanc Formation underlies the Grand River 

Group in Charlevoix County. The Bois Blanc Formation forms 

the bedrock surface of Gull and High Island, the southern por‐

tion Garden Island, and the northern portion of Beaver Island 

(Milstein, 1987). The Bois Blanc Formation is predominately 

composed of carbonates, including limestone, dolomite with 

chert, and dolomitic limestone. Portions of the formation are 

fossiliferous (Gardner, 1974). The formation is up to 360 ft 

thick (Catacosinos and others, 2001).

The Garden Island Formation underlies the Bois Blanc 

Formation when both are present. Within the State, the Garden 

Island Formation has patchy occurrences (Gardner, 1974), 

and ranges in thickness from 3 to 20 ft (Catacosinos and oth‐

ers, 2001). The Garden Island Formation contains dolomitic 

sandstone, sandy dolomite, and dolomite with chert nodules 

(Gardner, 1974). The bedrock surface of Hog Island and the 

northern portion of Garden Island is composed of the Garden 

Island Formation (Milstein, 1987).

Cheboygan County

Cheboygan County is in the northern Lower Peninsula of 

Michigan. The Boardman-Charlevoix, Lone Lake-Ocqueoc, 

Cheboygan, Black, and Lake Huron watersheds are the surface 

water drainages in the county. According to the February 2005 

Wellogic database, approximately 84 percent of the wells in 

Cheboygan County are completed in the glacial deposits, and 

9 percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 7 percent of the wells in the 

county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

14  Summary of Hydrogeologic Conditions by County for the State of Michigan
gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). The glacial deposits are up to 

600 ft thick in Cheboygan County. However, the majority of 

the glacial deposits are 201 to 400 ft thick (Western Michigan 

University, 1981). The glacial deposits in the county consist of 

till, outwash, and lacustrine deposits. The northern and central 

portions of the county consist of coarse‐grained lacustrine 

deposits and areas of coarse‐grained till. Drumlins are present 

in the northeastern portion of the county, while eskers are 

present in the southeastern portion. The southern portion of 

the county is composed of outwash and ice‐contact outwash, 

along with coarse‐grained till. The outwash deposits consist of 

sand and gravel. In addition, sand dunes are present along the 

Lake Huron shoreline and interspersed along the northern and 

central portion of the county. A small area of peat and muck 

occurs in the northwestern portion of the county (Farrand and 

Bell, 1982).

 The bedrock units underlie the glacial deposits through‐

out Cheboygan County. The bedrock surface, from south to 

north, is composed of the Antrim Shale, Traverse Group, 

Dundee Limestone, Detroit River Group, and Bois Blanc 

Formation (Milstein, 1987). These layers were deposited 

during the Devonian Period. The Antrim Shale is composed 

of primarily carbonaceous, black to dark‐gray shale. Near the 

base of the sequence, thin layers of gray shale and limestone 

may occur. The major constituents in the Antrim Shale consist 

of quartz, illite, and kerogen. Kaolinite, chlorite, and pyrite 

also compose the Antrim Shale. The Antrim Shale has been 

found to have bituminous limestone concretions up to 3 ft in 

diameter (Matthews, 1993). The Antrim Shale may be up to 

656 ft thick, which occurs at the center of the Michigan Basin 

(Gutschick and Sandberg, 1991). Very few bedrock wells are 

located where the Antrim Shale forms the bedrock surface.

The Traverse Group primarily consists of fossiliferous 

limestone. In the western portion of the basin, porous dolo‐

mite and anhydrite may be present. In the eastern portion of 

the basin, interlayers of shale are common. (Gardner, 1974). 

The basal formation of the Traverse Group is the Bell Shale. 

Bell Shale has a maximum thickness of 80 ft (Catacosinos and 

others, 2001). Bedrock wells are located where the Traverse 

Group forms the bedrock surface.

 Gardner (1974) divided the Dundee Limestone into the 

Roger City Member and underlying Reed City Member. The 

Rogers City Member is composed of dolomitized limestone 

in the western portion of the state and impermeable limestone 

in the eastern portion of the state. The Reed City member is 

composed of porous dolomite underlain by anhydrite. The 

anhydrite is absent in the eastern portion of the state (Gardner, 

1974).

In the subsurface, the Detroit River Group consists of 

the Lucas Formation, Amherstburg Formation, and Sylvania 

Sandstone. The Lucas Formation is primarily composed of 

interlayered carbonates and evaporates with carbonate‐ce‐

mented, fine‐ to medium‐grained, sandstone lenses found near 

the basal portion of the formation. The Lucas Formation is up 

to 1,050 ft in thickness in the Michigan Basin. In some areas, 

the water from this formation is brine and may contain hydro‐

gen sulfide. The Amherstburg Formation underlies the Lucas 

Formation. The Amherstburg Formation is up to 300 ft thick 

and is composed of fossiliferous limestone that is dolomitized 

in some areas. An upper sandstone is present in the formation 

in the western portion of the basin. The Sylvania Sandstone 

underlies the Amherstburg Formation. The Sylvania Sandstone 

is composed of fine‐ to medium‐grained sandstone with quartz 

overgrowths interlayered with carbonate. Sylvania Sandstone 

has been eroded in some areas of the basin (Gardner, 1974).

The Bois Blanc Formation underlies the Grand River 

Group in Emmet County. The Bois Blanc Formation is 

predominately composed of carbonates, including limestone, 

dolomite with chert, and dolomitic limestone. This forma‐

tion may be fossiliferous in places. The basal unit of the Bois 

Blanc formation is composed of a clastic or conglomerate 

layer (Gardner, 1974). In the northern portion of the county, 

bedrock wells are also used where the Dundee Limestone, 

Detroit River Group, and Bois Blanc Formation form the bed‐

rock surface. According to the Public Water Supply database, 

the estimated transmissivity for a well completed in the Detroit 

River Group is approximately 6,523 ft2/day.

Chippewa County

Chippewa County is in the eastern portion of the Upper 

Peninsula of Michigan. The Betsy‐Chocolay, Tahquame‐

non, Waiska, Lake Superior, St. Marys, Carp‐Pine, and Lake 

Huron watersheds are located in the county. According to the 

February 2005 Wellogic database, approximately 48 percent 

of the wells in Chippewa County are completed in the glacial 

deposits, and 48 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 4 percent of the 

wells in the county. The glacial aquifer overlies the bedrock 

aquifers, except where glacial deposits are absent. The glacial 

aquifer may be locally confined.

The thickness of glacial deposits ranges from 0 to greater 

than 150 ft in Chippewa County. Glacial deposits are discon‐

tinuous and thin in areas where bedrock elevations are high. 

On the eastern side of the county, valleys in the bedrock have 

been filled with glacial sediments and may provide excellent 

sources of groundwater. One bedrock valley is located from 

Whitefish Bay to Lake Huron following the Waiska and Pine 

Rivers. Another extends from Brimley to Neebish Island along 

the Charlotte River. North of the Niagara escarpment, a third 

bedrock valley filled with glacial deposits follows the Munus‐

cong River.

 Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeabil‐

ity. Glacial deposits are heterogeneous in the subsurface and 

cannot be regionally correlated (Westjohn and Weaver, 1994). 

Glacial deposits in Chippewa County are composed of till, out‐

wash, lacustrine sediments, and dunes. Most of the moraines 

County Summaries 15
in Chippewa County were originally deposited in glacial Lake 

Algonquin. Moderate supplies of water are possible from 

sand and gravel till found in moraines, predominately on the 

eastern part of the county. Poor sources of water are found in 

clay‐rich till primarily in the western part of the county. The 

moraines north of the Black River escarpment are composed 

of sand and gravel dominated till, while the moraines south of 

the Black River escarpment are composed of clay dominated 

till or boulder and clay dominated till. Moraines that con‐

tain large amounts of outwash yield large supplies of water. 

Till‐plain deposits are predominately till and often lie above 

the water table in Chippewa County. Till‐plain deposits are not 

an adequate source of water in Chippewa County. The most 

permeable glacial deposits are outwash plains and consist 

primarily of sand and gravel (Vanlier and Deutsch, 1958a). In 

the Bay Mills Indian Community, located in the northeastern 

portion of the county in the St. Marys watershed, an aquifer 

test was performed for a well in the sand and gravel aquifer. 

The estimated transmissivity and storage coefficient are 4,300 

ft2/day and 0.0005, respectively (Weaver, 1996). Lacustrine 

sediments are not a sufficient source of water, but tend to 

overlie sand and gravel deposits from outwash or till creating a 

confining layer in these areas. Dune deposits may yield small 

supplies of water from shallow wells and also provide areas of 

recharge. Dune deposits occur throughout the county, but are 

concentrated near Whitefish Bay.

The bedrock aquifers underlie glacial deposits in most 

of Chippewa County. The bedrock units in the county dip 

to the south, toward the center of the Michigan Basin. As a 

result, bedrock units in the county tend to thin to the north. 

(Vanlier and Deutsch, 1958a). The uppermost bedrock layers 

in Chippewa County are composed of limestone and dolomite, 

including the Engadine Dolomite, Manistique Dolomite, Burt 

Bluff Formation, and Cataract Formation. The first layer is 

approximately 500 ft thick, contains chert and gypsum, and 

solution cavities are present that provide areas of recharge 

and yield moderate amounts of water. Water derived from 

the Cataract Formation tends to be of poor quailty due to the 

gypsum present in this layer. The bottom of the first layer 

contains dolomitic shale at the base, which may confine the 

second bedrock layer composed of dolomite and limestone 

of the upper portion of the Richmond Group. This layer is 

approximately 240 ft thick. Shale layers within the Richmond 

Group may produce areas of lower permeability. Shale from 

the base of the Richmond Group and the Collingwood Forma‐

tion overlies the possibly confined limestone and dolomite 

from the Trenton Formation and underlying Black River 

Formation, and is approximately 210 ft thick. The Trenton and 

Black River Formations contain lenses of sand in certain areas. 

However, permeability generally decreases with depth in this 

layer. In the Rudyard area, water containing sulfur has come 

from the Trenton and Black River Formations. The base of the 

Black River Formation is shale (Vanlier, 1959). The Prairie du 

Chien Group, Munising Formation, and Jacobsville Sandstone 

underlie the Black River Formation. The Prairie du Chien 

Group and underlying Munising Formation combined are 180 

to 600 ft thick in Chippewa County (Vanlier and Deutsch, 

1958a; Gillespie and Dumouchelle, 1989). Dolomite and sand‐

stone, along with shale comprise the Prairie du Chien Group 

(Catacosinos and others, 2001). The Munising Formation 

is composed of well‐sorted, medium‐grained sandstone and 

friable, poorly sorted sandstone (Gillespie and Dumouchelle, 

1989). In the northern part of Chippewa County, near the 

Sault Ste. Marie‐Sugar Island area, the Jacobsville Sandstone 

forms the bedrock surface sometimes beneath 300 ft of glacial 

deposits, or at the surface, where glacial deposits are absent 

(Vanlier and Deutsch, 1958a; Gillespie and Dumouchelle, 

1989). The Jacobsville Sandstone is 120 to greater than 1,300 

ft thick (Vanlier and Deutsch, 1958a). The Jacobsville Sand‐

stone includes lenses of shale and conglomerate in arkose 

sandstone (Gillespie and Dumouchelle, 1989). The Jacobsville 

Sandstone is a productive aquifer in areas of Chippewa County 

(Gillespie and Dumouchelle, 1989). In the Bay Mills Indian 

Community, the Jacobsville Sandstone locally yields saline 

water (Weaver, 1996).

Clare County

Clare County is in the north‐central Lower Peninsula of 

Michigan. The Muskegon, Tittabawassee, and Pine watersheds 

drain Clare County. According to the February 2005 Wel‐

logic database, approximately 98 percent of the wells in Clare 

County are completed in the glacial deposits, and 0 percent in 

the bedrock units. There is insufficient information to make 

this distinction for 2 percent of the wells in the county. The 

southeastern portion of Clare County has fairly well‐drained 

soils of medium texture. The remainder of the county gener‐

ally has sandy well‐drained soils (Michigan Water Resources 

Commission, 1960).

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). Glacial deposits are 200 to 800 

ft thick in Clare County (Western Michigan University, 1981). 

The glacial deposits are composed of till and outwash. Fine to 

coarse‐grained till is interspersed on the surface of the county. 

The majority of the coarse‐grained till is near the center of 

the county (Farrand and Bell, 1982). A morainic belt extends 

across the county trending northeast to southwest (Michigan 

Water Resources Commission, 1960). Outwash is present on 

the surface along the northwestern edge of the county (Far‐

rand and Bell, 1982). Outwash is highly permeable and is 

composed of sand and gravel. Glacial wells in the county, 

according to the Public Water Supply database, have estimated 

transmissivities from aquifer tests that range from approxi‐

mately 2,260 to 17,650 ft2/day. Bedrock underlies the glacial 

deposits, but is not currently used for water supply.

16  Summary of Hydrogeologic Conditions by County for the State of Michigan
Clinton County

Clinton County is in the south‐central Lower Peninsula 

of Michigan. The Upper Grand watershed and the Maple 

watershed cross the southern and northern parts of the county. 

According to the February 2005 Wellogic database, approxi‐

mately 10 percent of the wells in Clinton County are com‐

pleted in the glacial deposits, and 86 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 4 percent of the wells in the county. Aquifers in the glacial 

and bedrock aquifers provide water in Clinton County, but 

generally are not as highly productive in the northwestern part 

(Vanlier and others, 1973).

The glacial deposits in Clinton County range in thick‐

ness from less than 10 ft to over 300 ft. The glacial features in 

Michigan are the result of ice advances during late Wisconsin 

time (35,000 to 10,000 years before present). Glacial deposits 

are of three principal types: 1) a well‐sorted mixture of silt, 

sand, and gravel, such as valley outwash, outwash plains, 

eskers, kames, and buried outwash, deposited by streams 

of melt water draining from glaciers, 2) a layered sequence 

of silt, sand, and clay deposited in glacial lakes, and 3) an 

unsorted mixture of clay, silt, sand, gravel, and boulders, such 

as till, deposited directly from the melting ice (Vanlier and 

others, 1973). None of these deposits are regionally continu‐

ous (Mandle and Westjohn, 1989).

Glacial deposits are the uppermost aquifer in Clinton 

County. Ground‐water flow in the glacial deposits is gener‐

ally from south to north, away from topographic divides and 

towards surface‐water bodies. Aquifers in the glacial deposits 

are composed of coarse alluvial and outwash materials. Long, 

narrow ridges of sand and gravel, called eskers, are present 

in parts of Clinton County, primarily in the southeast. Hills 

or mounds of sand and gravel, called kames, are also pres‐

ent primarily in the southeast part of Clinton County. Both 

of these may provide water to wells in the area (Vanlier and 

others, 1973). Buried outwash deposits were formed as areas 

of outwash deposited by a preceding glacier were covered by a 

layer of till deposited during a later glacial advance. The most 

extensive area of buried outwash deposits is in the southern 

part of Clinton County. These areas of buried outwash are 

a potential source of water to wells; however, most wells in 

these areas are completed in bedrock aquifers because of the 

better quality water available. Lake plain deposits, consisting 

of beds of clay, silt, and sand deposited in glacial lakes, under‐

lie parts of Clinton County; however, these deposits generally 

are thin and in most places and are not a source of water to 

wells (Vanlier and others, 1973). Till is present over much 

of the county and is generally not a source of water to wells 

(Vanlier and others, 1973). Locally the till may include thin 

beds of sand and gravel that may be a source of water or may 

overlies bodies of sand and gravel that may yield moderate 

to large supplies of water (Vanlier and others, 1973). The till 

underlying the Flint moraine in the southern part of the Elsie 

area is of greater permeability and includes more beds of sand 

and gravel than the till deposits in the northern part of Duplain 

Township. According to the Public Water Supply database, the 

estimated transmissivity for glacial wells ranges from approxi‐

mately 540 to 20,050 ft2/day.

The glacial deposits of Pleistocene age overlie Penn‐

sylvanian [and Upper Jurassic] bedrock units in Ingham 

County. Rocks of Triassic, [Lower and Middle] Jurassic, and 

Cretaceous age are missing (Mandle and Westjohn, 1989). 

The Jurassic “red beds” which separate Pennsylvanian rocks 

from glacial deposits in some areas of the Lower Peninsula, 

are either entirely absent or only marginally present in the 

Tri‐County region, which consists of Ingham, Clinton, and 

Eaton Counties (Westjohn and others, 1994). The “red beds” 

are often poorly consolidated or unconsolidated and consist of 

primarily clay, mudstone, siltstone, sandstone, shale and gyp‐

sum. The “red beds” are relatively impermeable and are con‐

sidered a confining unit. The “red beds” impede the vertical 

flow of water between glacial and bedrock aquifers (Westjohn 

and others, 1994).

Discontinuous lenses of sandstone, shale, coal, and lime‐

stone in the Pennsylvanian bedrock units have been formally 

subdivided into two formations. The uppermost massive, 

coarse‐grained sandstones form the Grand River Formation; 

all remaining Pennsylvanian rocks are considered part of the 

underlying Saginaw Formation (Mandle and Westjohn, 1989). 

The Grand River Formation, although removed by erosion 

after deposition over a large part of Clinton County, ranges 

in thickness up to 125 feet thick in some parts of the county 

(Vanlier and others, 1973). These assignments between forma‐

tions are somewhat uncertain, however, because no lithologic 

differences or stratigraphic horizons mark a change from one 

formation to the next (Westjohn and Weaver, 1996a). The 

Pennsylvanian bedrock unit ranges in thickness from less than 

50 to over 400 ft in Clinton County.

The basal part of the Pennsylvanian Saginaw Forma‐

tion is considered to be the Parma Sandstone although the 

stratigraphic relationship is not clear between the Saginaw 

Formation, Parma Sandstone, and the underlying Bayport 

Limestone. The Parma Sandstone is composed of medium‐ to 

coarse‐grained sandstone and is generally less than 100 ft 

thick (Cohee and others, 1951). Interpretation of geophysi‐

cal logs indicates that the lower part of the Pennsylvanian 

rock sequence is predominantly shale, whereas the upper part 

is predominantly sandstone. Thus, the Pennsylvanian rocks 

younger than the Parma Sandstone can be divided into a lower 

confining unit and an upper sandstone aquifer (Westjohn and 

Weaver, 1996a).

The Saginaw aquifer is in the water‐bearing sandstones in 

the Grand River and Saginaw Formations. Most ground‐water 

flow in the Saginaw aquifer is from south to north, although a 

small amount is toward local pumping centers. The Saginaw 

aquifer is recharged principally by leakage from the glacial 

deposits. Ground water also discharges locally from bed‐

rock to the glacial deposits beneath valleys of major streams 

(Holtschlag and others, 1996). The Grand River and Saginaw 

Formations act as a single hydrologic unit, so the chemical 

characteristics of water in these formations are very similar. 

County Summaries 17
Nearly all wells tapping these formations yield water that 

is suited to household needs. The water is generally hard or 

very hard and contains iron, although, in some localities, the 

Saginaw Formation yields soft water (Vanlier and others, 

1973). Analyses of aquifer‐test data indicate a wide range 

of transmissivities within the Saginaw aquifer. Wood (1969) 

reported that pumping tests indicated a relatively constant 

permeability of the sandstone in the Saginaw Formation of 

about 100 gpd/ft2 (13 ft/day). The permeability of the shale 

is more variable, ranging from 0.01 to 1.0 gpd/ft2 (0.001 to 

0.13 ft/day) (Wood, 1969). Transmissivities that range from 

130 to 2,700 ft2/day were reported for the Saginaw aquifer for 

the three‐county area of Clinton, Ingham, and Eaton Counties 

by Vanlier and Wheeler (1968). This range in transmissivi‐

ties reflects variations in the total thickness of the sandstone 

beds in the formation and variations in the permeability of the 

sandstone. According to the Public Water Supply database, the 

estimated transmissivity for the Saginaw aquifer ranges from 

approximately 450 to 3,890 ft2/day. Measured porosities and 

matrix‐controlled vertical hydraulic conductivities range from 

4 to 34 percent and 0.0001 to 55 ft/day, respectively (Westjohn 

and Weaver, 1996a).

Underlying the Saginaw Formation are beds of Mis‐

sissippian age – the Bayport Limestone and the Michigan 

Formation. The Bayport Limestone is a fossiliferous, cherty 

limestone, often with interbedded sandstone and varies con‐

siderably in thickness from one area to another. The Bayport 

Limestone and Parma Sandstone appear to interfinger through‐

out the Michigan Basin. These units are stratigraphically con‐

tinuous and hydraulically connected, and together they form 

the Parma‐Bayport aquifer (Westjohn and Weaver, 1996a). 

Please note that due to the uncertainty of stratigraphic relation‐

ship between these units, in other reports this aquifer may be 

delineated differently. The Michigan Formation is composed 

primarily of shale but includes beds of sandstone, limestone, 

and gypsum (Vanlier and others, 1973). Both the Bayport and 

Michigan Formations yield saline water where they are over‐

lain by the Saginaw Formation.

Crawford County

Crawford County in the central‐northern portion of the 

Lower Peninsula of Michigan. The Muskegon, Manistee, and 

Au Sable watersheds cross Crawford County. According to the 

February 2005 Wellogic database, approximately 99 percent 

of the wells in Crawford County are completed in the glacial 

deposits, and 0 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 1 percent of the 

wells in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional his‐

tory (Westjohn and others, 1994). The majority of the glacial 

deposits in Crawford County range from 401 to 600 ft thick. 

However, the thickness of the glacial deposits spans from 201 

to 1,000 ft thick in the county (Western Michigan University, 

1981). The majority of Crawford County is composed of sand 

and gravel outwash deposits. Poorly sorted, ice‐contact out‐

wash deposits are also scattered through the county. A small 

area, in the central eastern portion of the county, is composed 

of silt and clay lacustrine deposits (Farrand and Bell, 1982). 

Glacial wells in the county, according to the Public Water 

Supply database, have estimated transmissivities from aquifer 

tests that range from approximately 7,060 to 12,500 ft2/day. 

Bedrock underlies the glacial deposits, but it is not currently 

used for water supply.

Delta County

Delta County is in the central portion of the Upper 

Peninsula. The Cedar‐Ford, Escanaba, Tacoosh‐Whitefish, 

Fishdam‐Sturgeon, Manistique, and Lake Michigan water‐

sheds are included in the county. According to the February 

2005 Wellogic database, approximately 7 percent of the wells 

in Delta County are completed in the glacial deposits, and 88 

percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 5 percent of the wells in the 

county. Generally, the glacial aquifer is unconfined. However, 

in areas where lenses of clay are present in the glacial depos‐

its, the aquifer may become semi‐confined or confined. The 

occurrence of glacial wells increases near the center of the 

county, in a cluster that trends northwest to southeast.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). Aquifers in the glacial deposits consist largely 

of sands and gravels, and vary regionally in thickness and 

permeability. The glacial deposits range in thickness from 0 

to greater than 200 ft in Delta County. The glacial deposits are 

thin and discontinuous in the southern and western portions 

of the county, and thicker in the northeastern part (Sinclair, 

1960). The glacial deposits in Delta County are composed of 

till, outwash, and lacustrine deposits. Discontinuous exten‐

sions of the Newberry and Munising Moraines exist in the 

northeastern part of Delta County. These moraines are pre‐

dominantly composed of sand‐ and gravel‐rich till, however, 

the clay content increases to the south. Generally, the moraines 

in the northeastern portion of the county are above the water 

table. A moraine extends north to south along the western side 

of the county and is composed of a thin layer of coarse till. A 

segment of Cooks Moraine in T41N, R18W, consists primar‐

ily of silty sand; however, the till ranges from clay to boulder 

size. In the northeastern portion of Delta County large deposits 

of sand and gravel outwash are present. Lacustrine deposits 

are present primarily in the southeastern portion of the county, 

and are primarily composed of sand with some clay and silt. In 

18  Summary of Hydrogeologic Conditions by County for the State of Michigan
addition, wetlands often overlay the lacustrine deposits. Dune 

sand deposits can be found throughout the county, and often 

act as areas of ground‐water recharge (Sinclair, 1960).

The bedrock units underlie the glacial deposits through‐

out the county except where the bedrock units outcrop. The 

units that form the bedrock surface generally subcrop trending 

southwest to northeast. The youngest layers form the bed‐

rock surface in the southeastern portion of the county and get 

progressively older to the northwest. The bedrock layers thin 

to the northwest, because individual bedrock layers dip toward 

the southeast. The estimated transmissivity values for the bed‐

rock aquifers ranges between 45 and 800 ft2/day. These values 

were calculated using specific capacity data (Sinclair, 1960).

From youngest to oldest, the Engadine Dolomite, 

Manistique Dolomite, Burnt Bluff Formation, and Cataract 

Formation form the uppermost bedrock layers. The Engadine 

Dolomite is not aerially extensive, and is approximately 10 ft 

thick where present. The Engadine Dolomite is generally not 

considered a source of water in Delta County because of its 

very limited extent. The Manistique Dolomite contains chert, 

and is up to 150 ft in thickness. The Burnt Bluff Formation is 

composed of dolomite that is up to 250 ft thick. This bedrock 

unit typically yields moderate amounts of water, especially 

in the Garden Peninsula. The Cataract Formation is approxi‐

mately 250 ft thick, and is primarily dolomite, with shale 

and gypsum. Shale may retard the flow of water in areas, 

while moderate yields of water are due to the solution cavi‐

ties formed from gypsum. Estimated transmissivity for the 

Cataract Formation ranges between 170 and 880 ft2/day. Water 

derived from the Cataract Formation is usually poor quality 

as a result of dissolution of gypsum in the formation (Sinclair, 

1960). The base of the Cataract Formation contains dolomitic 

shale that may act as a confining layer (Vanlier and Deutsch, 

1958a).

The Richmond Group underlies the Cataract Formation. 

The Richmond Groups is composed of limestone and dolomite 

with some shale. Few fractures in the limestone and dolo‐

mite, and the presence of shale hinder the flow of water in the 

Richmond Group. The lower portion of the Richmond Group, 

and the underlying Collingwood Formation, form a shale layer 

that ranges in thickness from 130 to 300 ft. This may act as a 

confining layer. Limestone and dolomite from the Trenton and 

Black River Formations underlies the Collingwood Formation. 

Estimated transmissivity for the Trenton and Black River For‐

mations ranges between 45 and 370 ft2/day. The western por‐

tion of the county uses this aquifer as a main source of water, 

but the yield from these wells is often low (Sinclair, 1960). 

The base of the Black River Formation is shale that may act 

as a confining layer (Vanlier, 1959). Below this lies sandstone 

from the Au Train Formation (Hermansville) and Munising 

Sandstone, which may be hydraulically connected (Sinclair, 

1960). The estimated transmissivity for well completed in 

the Au Train Formation and Munising Sandstone are 450 and 

700 ft2/day, respectively. The Jacobsville Sandstone may not 

be present in Delta County. Below this, are metamorphic and 

igneous Precambrian rocks that are too deep and impermeable 

to supply water (Sinclair, 1960).

Dickinson County

Dickinson County is in the western Upper Peninsula of 

Michigan. The Michigamme, Menominee, Cedar‐Ford, and 

Escanaba watersheds drain through the county. An area in the 

northwest portion of the county is drained by the Michigamme 

River. The Menominee River traces the southern border of 

the county, and drains the central and southern portions of 

the county via the Pine and Sturgeon Rivers. The Ford and 

the West Branch of the Escanaba River drain the remaining 

northern part of the county (Hendrickson and Doonan, 1966). 

According to the February 2005 Wellogic database, approxi‐

mately 45 percent of the wells in Dickinson County are com‐

pleted in the glacial deposits, and 53 percent in the bedrock 

units. There is insufficient information to make this distinc‐

tion for 2 percent of the wells in the county. Hendrickson and 

Doonan (1966) identify three aquifers within the county: the 

glacial aquifer, the Paleozoic aquifer, and the Precambrian 

aquifer. It is not clear whether these aquifers are confined 

or unconfined. However, the glacial aquifer appears to be 

unconfined except where the glacial deposits underlie swamp 

deposits. In these areas, the glacial aquifer is semi‐confined 

or confined. In general, ground water in Dickinson County is 

hard, with high iron content in some areas (Hendrickson and 

Doonan, 1966).

Post‐glacial swamp deposits consist of peat and muck 

and are found in lowland areas near streams, lakes, and former 

lakes in areas of Dickinson County. The glacial aquifer ranges 

in thickness from 0 to 100 ft. Most wells in Dickinson County 

acquire water from sand‐and‐gravel outwash or kame depos‐

its. Outwash is primarily composed of stratified sand and 

gravel with some silt and clay. Stratified gravel, sand, silt, and 

clay also compose kame deposits, along with large areas of 

unsorted till. The sand and gravel, in the kame deposits, gener‐

ally occurs as discontinuous lenses. Wells completed in till 

usually supply small amounts of water. Till generally occurs 

in moraines and till plains and is composed of poorly sorted 

clay, silt, sand, and stones. End moraines in the county contain 

areas of sandy till, which also contain lenses of sand and 

gravel. These areas are capable of supplying larger amounts of 

water. The estimated transmissivity of the glacial aquifer was 

calculated using the specific capacity values of Hendrickson 

and Doonan (1966), and ranges from approximately 98 to 

3,948 ft2/day. According to the Public Water Supply database, 

the estimated transmissivity for glacial wells ranges from 

approximately 1,870 to 8,640 ft2/day.

Kingsford and Iron Mountain are located in the south‐

western corner of the county in Breitung Township. Glacial 

aquifers supply the majority of ground water in the area, and 

ground water flows to the west or southwest. In the Kingsford 

and Iron Mountain area, the thickness of the glacial depos‐

its ranges between 0 and 480 ft. In this area, generally two 

County Summaries 19
glacial aquifers are present (Luukkonen and Westjohn, 2001). 

The upper terrace sand‐and‐gravel unit, which is 0 to 160 ft 

thick, is primarily composed of fine‐ to medium‐grained sand, 

along with variable amounts of silt and gravel (Engineering 

for Earth, Water, and Air Resources, Inc, 1987). The upper 

terrace unit has an estimated transmissivity between 9,100 

and 11,400 ft2/day. Underlying the upper terrace unit is a 

confining unit that is composed of lacustrine clay and silt and 

eolian silt. In the north and west of the Kingsford and Iron 

Mountain area the confining unit is primarily composed of 

silt and fine‐grained sand (Luukkonen and Westjohn, 2001). 

The confining unit ranges from 0 to 150 ft thick, and is absent 

in isolated areas in Kingsford. Where the confining unit is 

absent, the upper terrace and lower outwash units form one 

aquifer. The lower outwash sand‐and‐gravel unit underlies the 

confining unit where it is present, and ranges between 0 and 

237 ft in thickness. The lower outwash unit consists of fine‐ to 

coarse‐grained sand that is moderately well sorted with silt 

and gravel lenses or layers (Engineering for Earth, Water, 

and Air Resources, Inc, 1987). Luukkonen and Westjohn 

(2001) interpreted the outwash sand‐and‐gravel aquifer to be 

unconfined or confined in areas dependent upon the position 

of the water table. The lower outwash unit has an estimated 

transmissivity between 2,800 and 8,700 ft2/day, and for one 

well in Iron Mountain as much as 24,100 ft2/day. Lodgement 

till or the Vulcan Iron Formation underlies the lower outwash 

unit. These units range from 0 to 250 ft thick (Luukkonen and 

Westjohn, 2001).

Bedrock underlies glacial deposits in the county, except 

where bedrock is exposed at the surface. The bedrock consists 

of Paleozoic and Precambrian rocks. The Paleozoic rocks 

form the bedrock surface primarily in the eastern portion of 

the county. Isolated subcrops are present in other areas in 

the county. The Paleozoic aquifer supplies small to moderate 

water yields. The Paleozoic aquifer consists of Ordovician 

and Cambrian dolomites and sandstones (Hendrickson and 

Doonan, 1966). The estimated transmissivity of the Paleozoic 

aquifer was calculated using the specific capacity values of 

Hendrickson and Doonan (1966) and ranges from approxi‐

mately 43 to 3,440 ft2/day.

 The Precambrian rocks subcrop mainly in the central and 

western portion of the county. Small amounts of water may 

be obtained from shallow wells in Precambrian metamorphic 

and igneous rocks. Fractures, and therefore the permeability of 

the Precambrian rocks, decrease with depth (Hendrickson and 

Doonan, 1966). The estimated transmissivity of the Precam‐

brian aquifer was calculated using the specific capacity values 

of Hendrickson and Doonan (1966) and ranges from 13 to 

1,289 ft2/day.

Eaton County

Eaton County is in the south‐central Lower Peninsula 

of Michigan. The Upper Grand watershed, the Thornapple 

watershed, and the Kalamazoo watershed drain through the 

northern, western, and southern parts of the county. Accord‐

ing to the February 2005 Wellogic database, approximately 

18 percent of the wells in Eaton County are completed in the 

glacial deposits, and 69 percent in the bedrock units. There is 

insufficient information to make this distinction for 13 percent 

of the wells in the county. In northwestern Eaton County water 

resources are limited regionally, but are abundant locally. 

Aquifers in the glacial deposits are the primary source of water 

in the northwest; however, aquifers in the Saginaw and Michi‐

gan Formations provide water to some wells, but generally are 

not highly productive (Vanlier and others, 1973). In north‐

eastern Eaton County, the principal aquifers are in the glacial 

deposits and the Saginaw Formation. These aquifers will yield 

moderate to large supplies in some areas, but are not highly 

productive over much of the area (Vanlier and others, 1973). 

In southwestern Eaton County, the principal aquifers are in 

the glacial deposits and the Marshall Formation. The Saginaw, 

Bayport, and Michigan Formations, which are tapped by some 

household wells, generally are not sources of major water sup‐

plies (Vanlier and others, 1973). In southeastern Eaton County, 

water resources are moderately abundant. The principal aqui‐

fers of this part of the county are in the glacial deposits, the 

Saginaw Formation, and, in the southern edge of the area, the 

Michigan Formation (Vanlier and others, 1973).

The glacial deposits in Eaton County range in thickness 

from 0 to over 300 ft. The glacial deposits are absent in a 

small area of the north central part of Eaton County. The gla‐

cial features in Michigan are the result of ice advances during 

late Wisconsin time (35,000 to 10,000 years before present). 

Glacial deposits are of three principal types: 1) a well‐sorted 

mixture of silt, sand, and gravel, such as valley outwash, 

outwash plains, eskers, kames, and buried outwash, deposited 

by streams of melt water draining from glaciers, 2) a layered 

sequence of silt, sand, and clay deposited in glacial lakes, and 

3) an unsorted mixture of clay, silt, sand, gravel, and boulders, 

such as till, deposited directly from the melting ice (Vanlier 

and others, 1973). None of these deposits are regionally con‐

tinuous (Mandle and Westjohn, 1989).

Glacial deposits are the uppermost aquifer in Eaton 

County. Ground‐water flow in the glacial deposits is gener‐

ally from south to north, away from topographic divides and 

towards surface‐water bodies. Aquifers in the glacial deposits 

are composed of coarse alluvial and outwash materials. An 

outwash plain covering several square miles is just east of 

Eaton Rapids. In the northern part of this plain, the sand and 

gravel beds may yield large supplies of water to wells. A 

smaller outwash plain lies just east of Charlotte (Vanlier and 

others, 1973). Long narrow ridges of sand and gravel, called 

eskers, are present in Eaton County. Buried outwash deposits 

were formed as areas of outwash deposited by a preceding 

glacier were covered by a layer of till deposited during a later 

glacial advance. The most extensive area of buried outwash 

deposits are in the northeastern part of Eaton County. These 

areas of buried outwash are a potential source of water to 

wells; however, most wells in these areas are completed in 

bedrock aquifers because of the better quality water available. 

20 Summary of Hydrogeologic Conditions by County for the State of Michigan
Till is present over much of the county and is generally not a 

source of water to wells. Locally the till may include thin beds 

of sand and gravel that are a source of water or may overlies 

bodies of sand and gravel that may yield moderate to large 

supplies of water (Vanlier and others, 1973). According to the 

Public Water Supply database, the estimated transmissivity for 

glacial wells in the county ranges from approximately 615 to 

127,000 ft2/day.

The glacial deposits of Pleistocene age overlie Pennsylva‐

nian [and Upper Jurassic] and Mississippian bedrock units in 

Eaton County. Rocks of Triassic, [Lower and Middle] Jurassic, 

and Cretaceous age are missing (Mandle and Westjohn, 1989). 

The Jurassic “red beds” which separate Pennsylvanian rocks 

from glacial deposits in some areas of the Lower Peninsula, 

are either entirely absent or only marginally present in the 

Tri‐County region, which consists of Ingham, Clinton, and 

Eaton Counties (Westjohn and others, 1994). The “red beds” 

are often poorly consolidated or unconsolidated and consist of 

primarily clay, mudstone, siltstone, sandstone, shale, and gyp‐

sum. The “red beds” are relatively impermeable and are con‐

sidered a confining unit. The “red beds” impede the vertical 

flow of water between glacial and bedrock aquifers (Westjohn 

and others, 1994).

Discontinuous lenses of sandstone, shale, coal, and lime‐

stone in the Pennsylvanian bedrock units have been formally 

subdivided into two formations. The uppermost massive, 

coarse‐grained sandstones form the Grand River Formation; 

all remaining Pennsylvanian rocks are considered part of the 

underlying Saginaw Formation (Mandle and Westjohn, 1989). 

In Eaton County, erosion removed most of the Grand River 

Formation, and as a result only a few large remnants remain 

(Vanlier and others, 1973). These assignments between forma‐

tions are somewhat uncertain, however, because no lithologic 

differences or stratigraphic horizons mark a change from one 

formation to the next (Westjohn and Weaver, 1996a). The 

Pennsylvanian bedrock unit ranges in thickness from 0 to over 

400 ft and is absent in the extreme western and southern parts 

of Eaton County.

The basal part of the Pennsylvanian Saginaw Forma‐

tion is considered to be the Parma Sandstone although the 

stratigraphic relationship is not clear between the Saginaw 

Formation, Parma Sandstone, and the underlying Bayport 

Limestone. The Parma Sandstone is composed of medium‐ to 

coarse‐grained sandstone and is generally less than 100 ft 

thick (Cohee and others, 1951). Interpretation of geophysi‐

cal logs indicates that the lower part of the Pennsylvanian 

rock sequence is predominantly shale, whereas the upper part 

is predominantly sandstone. Thus, the Pennsylvanian rocks 

younger than the Parma Sandstone can be divided into a lower 

confining unit and an upper sandstone aquifer (Westjohn and 

Weaver, 1996a).

The Saginaw aquifer is in the water‐bearing sandstones in 

the Grand River and Saginaw Formations. Most ground‐water 

flow in the Saginaw aquifer is from south to north, although a 

small amount is toward local pumping centers. The Saginaw 

aquifer is absent along the western and southern parts of Eaton 

County. The Saginaw aquifer is recharged principally by leak‐

age from the glacial deposits. Ground water also discharges 

locally from bedrock to the glacial deposits beneath valleys of 

major streams (Holtschlag and others, 1996). The Grand River 

and Saginaw Formations act as a single hydrologic unit, so the 

chemical characteristics of water in these formations are very 

similar. Nearly all wells tapping these formations yield water 

that is suited to household needs. The water is generally hard 

or very hard and contains iron, although, in some localities, 

the Saginaw Formation yields soft water (Vanlier and others, 

1973). Analyses of aquifer‐test data indicate a wide range 

of transmissivities within the Saginaw aquifer. Wood (1969) 

reported that pumping tests indicated a relatively constant 

permeability of the sandstone in the Saginaw Formation of 

about 100 gpd/ft2 (13 ft/day). The permeability of the shale 

is more variable, ranging from 0.01 to 1.0 gpd/ft2 (0.001 to 

0.13 ft/day) (Wood, 1969). Transmissivities that range from 

130 to 2,700 ft2/day were reported for the Saginaw aquifer for 

the three‐county area of Clinton, Ingham, and Eaton Counties 

by Vanlier and Wheeler (1968). This range in transmissivi‐

ties reflects variations in the total thickness of the sandstone 

beds in the formation and variations in the permeability of the 

sandstone. According to the Public Water Supply database, 

the estimated transmissivity for wells completed in the Grand 

River and Saginaw Formations in Eaton County ranges from 

approximately 840 to 3,240 ft2/day. Measured porosities and 

matrix‐controlled vertical hydraulic conductivities range from 

4 to 34 percent and 0.0001 to 55 ft/day, respectively (Westjohn 

and Weaver, 1996a).

Underlying the glacial deposits in the western and 

southern part of Eaton County are beds of Mississippian age 

– the Bayport Limestone, the Michigan Formation, and the 

Marshall Sandstone. The Bayport Limestone is a fossilifer‐

ous, cherty limestone, often with interbedded sandstone and 

varies considerably in thickness from one area to another. The 

Bayport Limestone and Parma Sandstone appear to interfinger 

throughout the Michigan Basin. These units are hydrauli‐

cally connected, and together they form the Parma‐Bayport 

aquifer (Westjohn and Weaver, 1996a). Please note that due 

to the uncertainty of stratigraphic relationship between these 

units, in other reports this aquifer may be delineated differ‐

ently. The Michigan Formation is composed primarily of 

shale but includes beds of sandstone, limestone, and gypsum 

(Vanlier and others, 1973). Siltstone and anhydrite layers that 

are discontinuous and interposed with lower permeability 

lithologies are considered the Michigan confining unit. This 

unit separates the Parma‐Bayport aquifer from the underlying 

Marshall Sandstone. The Marshall Sandstone consists of a 

sequence of sedimentary rocks between the Coldwater Shale 

and the Michigan Formation. The Marshall aquifer consists of 

one or more stratigraphically continuous permeable sand‐

stones. In areas where the Marshall aquifer consists of two or 

more sandstones, these permeable strata typically are sepa‐

rated by beds of siltstone, shale and (or) carbonate (Westjohn 

and Weaver, 1996b). Both the Bayport and Michigan Forma‐

tions yield saline water where they are overlain by the Sagi‐

County Summaries  21
naw Formation. In southwestern Eaton County, the Bayport 

Limestone is overlain by glacial deposits and is a source of 

fresh water to household wells. Sandstone beds in the forma‐

tion supply many of these wells, although some limestone 

beds are also water producing (Vanlier and others, 1973). The 

Michigan Formation is a source of fresh water in southwestern 

and western Eaton County where it is overlain directly by the 

glacial deposits or by the Bayport Limestone. The quality of 

water yielded by the formation varies considerably. The Mar‐

shall Sandstone yields potable water in southwestern Eaton 

County and supplies water to municipal and household wells. 

In some areas the Marshall Sandstone yields fresh water where 

the overlying Michigan Formation yields saline water (Van‐

lier and others, 1973). According to the Public Water Supply 

database, the estimated transmissivity for a well completed 

in the Marshall Sandstone in Eaton County is approximately 

1,885 ft2/day. Analysis of aquifer tests of the Marshall aquifer 

in Muskegon, Genesee, and Eaton Counties indicate a small 

range of transmissivities (10 to 37 ft2/day) and hydraulic con‐

ductivities (0.2 to 0.5 ft/day) (Westjohn and Weaver, 1996b).

Emmet County

Emmet County is located in the northern Lower Pen‐

insula. The Boardman‐Charlevoix, Lake Michigan, Lone 

Lake‐Ocqueoc, Cheboygan, and Lake Huron watersheds 

are included in the county. According to the February 2005 

Wellogic database, approximately 75 percent of the wells in 

Emmet County are completed in the glacial deposits, and 11 

percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 14 percent of the wells in the 

county. The bedrock wells primarily occur in the northernmost 

and southernmost portions of the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history. In the Michigan 

Basin, the glacial aquifer consists of sand and gravel that is 

part of a thick sequence of Pleistocene glacial deposits (West‐

john and others, 1994). The majority of the glacial deposits in 

Emmet County range from 201 to 800 ft thick. However, the 

thickness of the glacial deposits spans from 0 to greater than 

1,000 ft in the county, generally thinning to the north (Western 

Michigan University, 1981). The glacial deposits in Emmet 

County include outwash, till, and lacustrine deposits. The 

outwash deposits are composed of sand and gravel. The till is 

primarily coarse‐grained material. Lacustrine deposits in the 

county are typically composed of sand and gravel. In addition, 

dune sand can be found along the shoreline of Lake Michigan. 

Also, peat and muck deposits occur in the central and north‐

western portion of the county (Farrand and Bell, 1982).

Bedrock underlies the glacial deposits in the county. The 

bedrock surface is composed of rocks of Devonian age, from 

south to north, these are the Antrim Shale, Traverse Group, 

Dundee Limestone, Detroit River Group and Bois Blanc For‐

mation. The Antrim Shale is composed of primarily carbona‐

ceous, black to dark‐gray shale. Near the base of the sequence, 

thin layers of gray shale and limestone may occur. The Antrim 

Shale is not considered an aquifer in Emmet County. The 

major constituents in the Antrim Shale consist of quartz, illite, 

and kerogen. Kaolinite, chlorite, and pyrite also compose 

the Antrim Shale. The Antrim Shale has been found to have 

bituminous limestone concretions up to 3 ft in diameter (Mat‐

thews, 1993). The Antrim Shale can be up to 650 ft thick at the 

center of the Michigan Basin (Gutschick and Sandberg, 1991).

The Traverse Group underlies the Antrim Shale. The 

Traverse Group primarily consists of fossiliferous limestone. 

In some areas the Traverse Group has been highly fractured 

which leads to local areas of very high permeability within 

that unit. In the western portion of the Michigan Basin, porous 

dolomite and anhydrite may be present. In the eastern portion 

of the basin, interlayers of shale are common. (Gardner, 1974). 

The basal formation of the Traverse Group is the Bell Shale. 

Bell Shale has a maximum thickness of 80 ft (Catacosinos 

and others, 2001). In the southern portion of Emmet County, 

bedrock wells are located where the Traverse Group forms the 

bedrock surface.

Bedrock wells occur in the northern portion of the 

county, where the remaining Devonian strata form the bedrock 

surface. The Dundee Limestone underlies the Traverse Group. 

Gardener (1974) divided the Dundee Limestone into the Roger 

City Member and underlying Reed City Member. The Rog‐

ers City Member is composed of dolomitized limestone in the 

western portion of the State and impermeable limestone in the 

eastern portion of the State. The Reed City member is com‐

posed of porous dolomite underlain by anhydrite. The anhy‐

drite is absent in the eastern portion of the State (Gardener, 

1974).

The Detroit River Group underlies the Dundee Lime‐

stone. In the subsurface, the Detroit River Group consists of 

the Lucas Formation, Amherstburg Formation, and Sylvania 

Sandstone. The Lucas Formation is primarily composed of 

interlayered carbonates and evaporates, with carbonate‐ce‐

mented, fine‐ to medium‐grained, sandstone lenses found 

throughout the basal portion of the formation. The Lucas 

Formation is up to 1,050 ft in thickness in the Michigan Basin. 

In some areas, the water from this formation is brine and may 

contain hydrogen sulfide. The Amherstburg Formation under‐

lies the Lucas Formation. The Amherstburg Formation is up 

to 300 ft thick and is composed of fossiliferous limestone that 

is dolomitized in some areas. An upper sandstone is present in 

the formation in the western portion of the basin. The Sylvania 

Sandstone underlies the Amherstburg Formation. The Sylvania 

Sandstone is composed of fine‐ to medium‐grained sandstone 

with quartz overgrowths interlayered with carbonate. (Gardner, 

1974).

The Bois Blanc Formation underlies the Grand River 

Group in Emmet County. The Bois Blanc Formation is 

predominately composed of carbonates, including limestone 

(which may be fossiliferous in some areas), dolomite with 

chert, and dolomitic limestone. The basal unit of the Bois 

22  Summary of Hydrogeologic Conditions by County for the State of Michigan
Blanc formation is composed of a clastic or conglomerate 

layer (Gardener, 1974).

Genesee County

Genesee County is in the eastern south‐central portion 

of the Lower Peninsula. The western half of Genesee County 

is located in the Saginaw Lowlands (Westjohn and Weaver, 

1998). The Shiawassee, Flint, and Cass watersheds drain the 

county. According to the February 2005 Wellogic database, 

approximately 23 percent of the wells in Genesee County 

are completed in the glacial deposits, and 73 percent in the 

bedrock units. There is insufficient information to make this 

distinction for 4 percent of the wells in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). Glacial deposits in 

Genesee County are primarily composed of materials with low 

permeability, primarily clay, silt, with some fine sand. Both 

the surficial and underground sand and gravel deposits vary 

in permeability both laterally and horizontally. Some of the 

sand and gravel deposits have been cemented with calcium 

carbonate, reducing permeability (Wiitala and others, 1963). 

Glacial deposits include till, outwash, and lacustrine deposits 

in Genesee County. The till in the county is fine to medium 

grained (Farrand and Bell, 1982). Till is present in moraines 

and till plains. Moraines are present across the county, trend‐

ing northeast to southwest. Till plains occur in the southern 

portion of the county. Glacial outwash occurs along the Shia‐

wassee and Flint Rivers. In the northern portion of the county, 

lacustrine deposits and beach deposits dominate the landscape. 

The permeability of glacial deposits varies in Genesee County. 

However, localized, sand and gravel lenses are present that are 

highly permeable. In Genesee County, the transmissivity val‐

ues for the glacial aquifer range between 300 to 9,350 ft2/day. 

Water from the glacial aquifer may be hard and/or contain 

high levels of iron and chloride. In the county, hydrogen sul‐

fide has been found in water from the glacial aquifer (Wiitala 

and others, 1963).

Bedrock underlies the glacial deposits. The Saginaw 

Formation, Michigan Formation, and Marshall Sandstone form 

the primary bedrock aquifers in Genesee County. The Saginaw 

Formation is thinnest at the contact with the Michigan Forma‐

tion and thickest in northwest Genesee County (up to 323 ft). 

The Saginaw Formation consists of discontinuous layers of 

sandstone, sandy shale, shale, coal, and limestone. The water 

obtained from the Saginaw Formation arises mainly from the 

sandstone beds that form the Saginaw aquifer (Wiitala and 

others, 1963; Westjohn and Weaver, 1996a). The Saginaw 

aquifer often supplies moderate to large supplies of water; 

however, the quality of the water may be a problem. The 

Saginaw aquifer may yield hard water that is high in chloride 

and iron. Although hardness and iron content is often lower 

in the Saginaw aquifer than the glacial aquifer, the chloride 

content is often much higher (Wiitala and others, 1963). In 

Genesee County, the Saginaw aquifer yields both fresh and 

saline water (Westjohn and Weaver, 1996c). Transmissiv‐

ity for the Saginaw aquifer in Genesee County ranges from 

200 to 1,800 ft2/day (Wiitala and others, 1963). The Saginaw 

confining unit underlies the Saginaw aquifer. The Saginaw 

confining unit is approximately 50 ft thick in the county. It is 

primarily shale, with thin layers of discontinuous sandstone, 

siltstone, limestone, and coal. The permeable layers within the 

Saginaw confining unit appear to be isolated from the regional 

ground‐water‐flow system (Westjohn and Weaver, 1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and is 

generally less than 100 ft thick (Cohee and others, 1951). The 

Bayport Limestone is a fossiliferous, cherty limestone, often 

with interbedded sandstone and varies considerably in thick‐

ness from one area to another. The Bayport Limestone and 

Parma Sandstone appear to interfinger throughout the Michi‐

gan Basin (Westjohn and Weaver, 1996a). Bayport Limestone 

is eroded completely in some areas in the county (Wiitala and 

others, 1963). These units are hydraulically connected, and 

together they form the Parma‐Bayport aquifer (Westjohn and 

Weaver, 1996a). The Parma‐Bayport aquifer is approximately 

100 to 150 ft thick within the Michigan Basin. Please note that 

due to the uncertainty of stratigraphic relationship between 

these units, in other reports this aquifer may be delineated dif‐

ferently. The Parma‐Bayport aquifer may contain saline water 

in Genessee County (Westjohn and Weaver, 1996c).

Bayport Limestone and the underlying Michigan For‐

mation subcrop, generally, between the Saginaw Formation 

and the Marshall Sandstone. In Genesee County, the Bayport 

Limestone and Michigan Formation have a combined maxi‐

mum thickness of 210 ft. The Michigan Formation is com‐

posed of sandstone, shale, limestone, and occasional dolo‐

mite. Gypsum and anhydrite are also present in the Michigan 

Formation. The lower permeability lithologies of the Michigan 

Formation are usually considered a confining unit (Westjohn 

and Weaver, 1996b). Some water, however, may be obtained 

locally from solution cavities from limestone or from sand‐

stone units, where the Michigan Formation forms the bedrock 

surface (Wiitala and others, 1963).

The Marshall Sandstone underlies the Michigan For‐

mation, and subcrops in areas along the eastern edge of the 

county, and near the southern part of the county. In Genesee 

County, the Marshall Sandstone is thickest in the northern 

portion and ranges in thickness from less than 70 to 200 ft. In 

general, the Marshall Sandstone consists of sandstone with 

some interbeds of shale, conglomerate, and dolomite (Wiitala 

County Summaries  23
and others, 1963). The Marshall Sandstone is often divided 

into two units the upper and lower Marshall sandstone. The 

upper is composed of quartzarenite to sublitharenite that is 

referred to as the Napoleon Sandstone Member. A shale, 

siltstone, and/or carbonate layer separate the Napoleon Sand‐

stone Member from the lower Marshall sandstone. The lower 

Marshall sandstone can be further divided into two units: an 

upper, fine‐ to medium‐grained quartzarenite to sublitharenite 

and a basal fine‐ to medium‐grained litharenite. The continu‐

ous sandstones in the Marshall Sandstone are considered the 

Marshall aquifer (Westjohn and Weaver, 1996b). In Genesee 

County, the Napoleon Sandstone Member may comprise most 

of the Marshall Sandstone. However near Grand Blanc Town‐

ship and the southern portion of Flint Township, there is an 

abundance of dolomite and shale where the Marshall Sand‐

stone is present. The majority of the wells that tap the Mar‐

shall Sandstone are located in the eastern and southern parts 

of Genesee County. The Marshall aquifer yields moderate to 

large supplies of water in areas of the county. Saline water is 

common where the Marshall Sandstone is overlain by younger 

bedrock. However, where the Marshall Sandstone forms the 

bedrock surface, the water is generally fresh (Wiitala and oth‐

ers, 1963).

Gladwin County

Gladwin County is in the north‐central portion of the 

Lower Peninsula of Michigan. The eastern portion of the 

county is in the Saginaw Lowlands (Westjohn and Weaver, 

1998). The Kawkawlin‐Pine and Tittabawassee watersheds 

drain the county. According to the February 2005 Wellogic 

database, approximately 75 percent of the wells in Gladwin 

County are completed in the glacial deposits, and 13 percent 

in the bedrock units. There is insufficient information to make 

this distinction for 12 percent of the wells in the county. The 

western side of the county contains primarily glacial wells, 

while the eastern portion of the county, in the Saginaw Low‐

lands, contains both glacial and bedrock wells.

Dune sand is present on the edge of the eastside of the 

county. In the western and northern portions of the county, 

the soils are fairly well drained and are medium textured. The 

northern border of the county has sandy hills, and sand is pres‐

ent in Gladwin County, east of the Tittabawassee River. The 

remainder of the county is covered in wet, sandy soils that are 

underlain by clay (Michigan Water Resources Commission, 

1960).

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). In Gladwin County, the thick‐

ness of the glacial deposits ranges from approximately 100 

to 600 ft. The thickness generally increases to the northwest 

(Western Michigan University, 1981). The glacial deposits are 

composed of lacustrine deposits, till, and outwash. Lacustrine 

deposits are present in the eastern and southern portion of the 

county. Both sand‐and‐gravel dominated and clay‐and‐silt 

dominated lacustrine deposits are present in the county. Till is 

present in moraines and till plains. Fine‐ to coarse‐grained till 

is present primarily in the northwestern corner of the county, 

but also occurs in areas of the eastern side of the county. 

Outwash is present along the northwestern edge of the county 

(Farrand and Bell, 1982). Outwash is highly permeable and is 

composed of sand and gravel. According to the Public Water 

Supply database, the estimated transmissivities from aqui‐

fer tests for the glacial wells in Gladwin County range from 

approximately 4,630 to 5,120 ft2/day.

Bedrock underlies the glacial deposits. According to the 

Public Water Supply database, the estimated transmissivities 

from aquifer tests for a bedrock well in Gladwin County is 

approximately 2,730 ft2/day. The bedrock surface of Gladwin 

County is composed of the Jurassic “red beds” and the Sagi‐

naw Formation (Milstein, 1987). The Jurassic “red beds” are 

generally 50 to 150 ft thick (Westjohn and others, 1994). “Red 

beds” occur primarily in the southern portion of the county 

(Milstein, 1987). The “red beds” consist of red clay, mudstone, 

siltstone, and sandstone, and also include gray‐green shale, 

gypsum, and mudstone (Shaffer, 1969). The “red beds” are 

considered to be a confining unit in Michigan (Westjohn and 

others, 1994).

The Saginaw Formation underlies the Jurassic deposits, 

when “red beds” are present. Interbedded sandstone, siltstone, 

shale, coal, and limestone compose the Saginaw Formation. 

The Saginaw aquifer is the hydraulically connected sandstones 

in the Saginaw Formation (Westjohn and Weaver, 1998). 

Within the State, the Saginaw aquifer ranges from less than 

100 to 370 ft thick. The Saginaw aquifer yields fresh water in 

Gladwin County (Westjohn and Weaver, 1996c). The Saginaw 

confining unit underlies the Saginaw aquifer, and ranges in 

thickness from less than 100 to 240 ft within the State. The 

Saginaw confining unit is mostly shale, with thin layers of 

discontinuous sandstone, siltstone, limestone, and coal. The 

permeable layers within the Saginaw confining unit appear to 

be isolated from the regional ground‐water‐flow system (West‐

john and Weaver, 1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably in 

thickness from one area to another. The Bayport Limestone 

and Parma Sandstone appear to interfinger throughout the 

Michigan Basin. These units are hydraulically connected, and 

together they form the Parma‐Bayport aquifer (Westjohn and 

24  Summary of Hydrogeologic Conditions by County for the State of Michigan
Weaver, 1996a). The Parma‐Bayport aquifer is approximately 

100 to 150 ft thick within the Michigan Basin. Please note that 

due to the uncertainty of stratigraphic relationship between 

these units, in other reports this aquifer may be delineated 

differently. The Parma‐Bayport aquifer yields saline water or 

brine in Gladwin County (Westjohn and Weaver, 1996c).

The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation consists of layers of sand‐

stone, siltstone, anhydrite or gypsum, dolomite, limestone, 

and shale. The lower permeability lithologies of the Michigan 

Formation are considered a confining unit that separates the 

Parma‐Bayport aquifer from the underlying Marshall aquifer. 

The thickness of the Michigan confining unit ranges from 

less than 50 to 400 ft within the State (Westjohn and Weaver, 

1998).

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone is composed of an upper quartz‐

arenite to sublitharenite that is referred to as the Napoleon 

Sandstone Member. A shale, siltstone, and/or carbonate layer 

separates the Napoleon Sandstone Member from the lower 

Marshall sandstone. The lower Marshall sandstone is com‐

prised of two units. The upper unit is generally 50 to 125 ft of 

fine‐ to medium‐grained quartzarenite to sublitharenite. At the 

base of the Marshall Sandstone is a fine‐ to medium‐grained 

litharenite that ranges in thickness from 30 to 125 ft. Perme‐

able sandstones in the Marshall Sandstone comprise the Mar‐

shall aquifer. The Marshall aquifer ranges in thickness from 75 

to greater than 200 ft within the State (Westjohn and Weaver, 

1998). The Marshall Sandstone yields saline water or brine in 

Gladwin County (Westjohn and Weaver, 1996c).

Coldwater Shale underlies the Marshall Sandstone. 

Coldwater Shale consists of primarily shale with interbeds or 

lenses of sandstone, siltstone, and dolomite. Coldwater Shale 

is relatively impermeable and is considered a confining unit in 

most of Michigan (Westjohn and Weaver, 1998).

Gogebic County

Gogebic County is along the western edge of the Upper 

Peninsula of Michigan. Gogebic County mainly drains into 

Lake Superior via the Black, Montreal, Presque Isle, or 

Ontonagon Rivers. In the southeastern portion of the county a 

small area drains into Lake Michigan. Ground‐water resources 

may be difficult to obtain and are not uniformly distributed in 

this area (Doonan and Hendrickson, 1968). According to the 

February 2005 Wellogic database, approximately 55 percent 

of the wells in Gogebic County are completed in the glacial 

deposits, and 41 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 4 percent of the 

wells in the county.

Postglacial deposits consist of swamp deposits and 

recent alluvium. These deposits are composed of muck, peat, 

sand, silt, and clay (Doonan and Hendrickson, 1968). In 

the southeastern area of the county, in the Lac Vieux Desert 

area, swamp deposits are often underlain by sand and gravel 

along with some clay (Barton and Grannemann, 1998). There 

is not much information available concerning the amount 

of water the swamp deposits may supply. However, where 

coarse‐grained glacial outwash underlies the postglacial 

deposits, ground water yields are high (Doonan and Hendrick‐

son, 1968).

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

Glacial deposits are heterogeneous in the subsurface. Glacial 

deposits in the county are composed of outwash, moraines, 

till‐plain, and lacustrine deposits. Outwash is primarily com‐

posed of sand and gravel with lenses of silt and clay. Outwash 

is most abundant in the southeastern and south‐central portion 

of the county. Large yields of ground water may be obtained 

from these deposits. Moraines dominate the eastern portion of 

the county, and occur sporadically throughout the rest of the 

county. In the south‐central and southwestern portions of the 

county, small to moderate yields of ground water are obtained 

from moraines. In other areas of the county, moraines may 

supply small to large amounts of water. Till plains, composed 

of a combination of boulders, gravel, sand, silt, and clay, 

dominate the west‐central portion of the county, and also occur 

throughout other areas of the county. In the west‐central por‐

tion of the county, sand and gravel dominates these deposits 

and moderate to large yields of ground water are obtained. 

Small to moderate ground‐water yields are acquired from 

till‐plain deposits in the rest of the county. Lacustrine deposits 

in this area are composed of silt and clay with lenses of fine 

sand and generally yield small amounts of ground water. In 

general, the ground water in the county may be moderately 

hard and contain iron. A few deep glacial wells in the county 

have tapped saline water. In Gogebic County the estimated 

transmissivity for glacial wells was calculated from the spe‐

cific capacity data of Doonan and Hendrickson (1968) and 

range from 63 to 20,174 ft2/day. According to the Public Water 

Supply database, the estimated transmissivity for glacial wells 

ranges from approximately 1,440 to 17,280 ft2/day.

The Lac Vieux Desert Indian Community and vicin‐

ity is located in the southeastern portion of Gogebic County 

and extends into Vilas County, Wisconsin. This area is in the 

Upper Wisconsin watershed, and Lac Vieux Desert, a 6.6 mi2

lake and its tributaries, are the headwaters of the Wisconsin 

River. Glacial deposits are up to 200 ft thick in this area. 

Drumlins are present in the southern and eastern borders of 

Lac Vieux Desert. The drumlins are composed of glacial 

deposits that are silty and clay rich, and till that is gravel and 

sand rich. In the Lac Vieux Desert area, the aquifer system is 

generally layered consisting of an unconfined aquifer under‐

lain by a confined aquifer or series of confined aquifers. In 

some areas only a confined aquifer may be present. The aqui‐

fer material is composed of sand and gravel and some clay. 

The aquifer material is generally 5 to less than 100 ft thick. A 

discontinuous gravel aquifer occurs in this area, approximately 

96 to 188 ft below ground, and has been recorded from 3 to 15 

ft thick in well logs. This gravel aquifer is capable of yields up 

to 30 gal/min. The confined aquifer tends to yield more water 

County Summaries  25
than the unconfined aquifer in this region. Confining layers are 

10 to 100 ft thick composed of till and debris‐flow deposits 

that are rich in clay. The water originating from the glacial 

aquifer is moderately hard and alkaline, and has low iron con‐

centrations (Barton and Grannemann, 1998).

The Bessemer area is located in the western Goge‐

bic County. In this area, much of the glacial aquifer is also 

considered confined or semi‐confined. This is due to a layer 

of impermeable till that covers most of this region. Transmis‐

sivity values in the glacial aquifer in the Bessemer area have 

been calculated from specific capacity data and range between 

2,502 and 9,240 ft2/day (Brown and Stuart, 1951).

Bedrock dips to the north, and consists of Precambrian 

metamorphosed and igneous rocks overlying older igneous 

and metamorphic rocks (Brown and Stuart, 1951). These 

rocks are relatively impermeable. Therefore, Barton and 

Grannemann (1998) consider the bedrock surface be the base 

of the aquifer in southeastern portion of the county. How‐

ever, in the western and central areas of the county, bedrock 

outcrops or maybe covered by only a thin layer of glacial 

deposits. Small water yields may be obtained from bedrock 

wells due to fracturing of the rock. Specific capacity data was 

available for one bedrock well in Gogebic County and used to 

calculate a transmissivity value of 4,065 ft2/day (Doonan and 

Hendrickson, 1968). According to the Public Water Supply 

database, the estimated transmissivity for a bedrock well in the 

county is approximately 2,320 ft2/day.

Grand Traverse County

Grand Traverse County is in the northwestern portion of 

the Lower Peninsula of Michigan. The Manistee, Betsie‐Platte, 

Boardman‐Charlevoix, and Lake Michigan watersheds drain 

the county. On the north, Grand Traverse County is bounded 

by the East and West arms of the Grand Traverse Bay. In 

the northwestern part of the county, near Bass Lake, a major 

groundwater divide extends north to south for about 10 mi 

and then continues eastward toward Fife Lake, in the south‐

eastern periphery of the county. Ground water flows into the 

Boardman River or Grand Traverse Bay, north and east of the 

divide. South and east of the divide, ground water flows into 

neighboring counties (Cummings and others, 1990). Accord‐

ing to the February 2005 Wellogic database, approximately 97 

percent of the wells in Grand Traverse County are completed 

in the glacial deposits, and 0 percent in the bedrock units. 

There is insufficient information to make this distinction for 3 

percent of the wells in the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits 

that resulted from a complex depositional history (Westjohn 

and others, 1994). Glacial deposits in Grand Traverse County 

range from 0 to 900 ft in thickness and are made up of an 

assemblage of outwash, till, and lacustrine deposits. The 

outwash deposits, which are composed of sand and gravel, are 

present on the surface in the majority of the county (Cum‐

mings and others, 1990). The Mancelona Outwash Plain 

separates the two portions of the Port Huron Moraine (Leverett 

and Taylor, 1915). Till deposits are made up of a wide array 

of materials including clay, silt, sand, gravel, and, occasion‐

ally, boulders. These deposits are found in moraines and till 

plains. Leverett and Taylor (1915) identified the northeast‐

ern moraine as the Inner Port Huron Moraine. The southern 

moraine is termed the Outer Port Huron Moraine (Leveret 

and Taylor, 1915). The Manistee Moraine is also present in 

the northwestern portion of the county. Blewett and Winters 

(1995) determined that the surficial deposits of the Port Huron 

Moraine were primarily composed of glaciofluvial sand and 

gravel. Thin layers of till separated by sand and silt may occur 

in the subsurface of the moraine. The base of the Port Huron 

Moraine is composed of thick clay and gravel (Boutt, 1999). 

Till plains contain drumlins and are found in the northeastern 

portion of the county and on Old Mission Peninsula. Lacus‐

trine deposits are present in the north‐central portion of the 

county and on Old Mission Peninsula. The lacustrine deposits 

are composed of sand, gravel, and clay, dependent upon the 

location (Twenter and others, 1985; Cummings and others, 

1990). Twenter and others (1985) studied the lacustrine depos‐

its in East Bay Township and the U.S. Coast Guard Air Station 

in greater detail. In this area, the lacustrine glacial deposits are 

composed of two units: a permeable sand and gravel unit and 

an underlying, relatively impermeable, clay unit. The sand and 

gravel unit has a total thickness from 29 to 188 ft. This unit 

is composed of 15 to 20 ft of fine‐ to medium‐grained sand, 

and below this depth coarser‐grained sand and gravel is more 

abundant. The underlying clay unit is estimated to be from 100 

to 200 ft thick. The clay unit dips to the east at 45 ft/mile or 

the southeast at 500 ft/mile (Twenter and others, 1985).

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits (Westjohn and others, 1994). Layers of till and 

clay form confining units and are found throughout the Grand 

Traverse County on the surface and in the subsurface. Lower 

units in the glacial deposits are confined or semi‐confined by 

these layers. Unconfined conditions exist where outwash and 

coarse‐grained lacustrine deposits are present at the surface 

and wells are often shallow, less than 100 ft in depth, in these 

areas (Cummings and others, 1990). Based on aquifer tests 

from the area, the estimated transmissivity and hydraulic 

conductivity for the glacial aquifer range from 1,800 to 2,500 

ft2/day and 50 to 150 ft/day, respectively (Twenter and others, 

1985; Cummings and others, 1990). According to the Public 

Water Supply database, the estimated transmissivity for glacial 

wells ranges from approximately 1,260 to 5,120 ft2/day. Bed‐

rock underlies the glacial deposits, but is not currently used for 

water supply.

Ground‐water quality is of interest in all Michigan coun‐

ties. In Grand Traverse County, nitrate concentrations in 1.6 

percent of the ground water sampled equaled or exceeded the 

U.S. EPA maximum contaminant level of 10 ppm. The mean 

concentration of nitrate in ground water in Grand Traverse 

26  Summary of Hydrogeologic Conditions by County for the State of Michigan
County is below U.S. EPA drinking water regulations (Cum‐

mings and others, 1990). Organic chemicals are present in the 

ground water in some areas of the county (Twenter and others, 

1985).

Gratiot County

Gratiot County is in the central part of the Lower Pen‐

insula of Michigan. The Maple, Pine, Tittabawassee, and 

Shiawassee watersheds drain the county in the southern, north 

central and northwest, northeast, and eastern portions of the 

county, respectively. The Tittabawassee watershed includes the 

northern portion of Gratiot County and contains soils that are 

intermediately drained and medium to heavy‐textured (Michi‐

gan Water Resources Commission, 1960). According to the 

February 2005 Wellogic database, approximately 85 percent 

of the wells in Gratiot County are completed in the glacial 

deposits, and 12 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 3 percent of the 

wells in the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). In the county, the thickness of the glacial depos‐

its ranges from 51 to 600 ft (Western Michigan university, 

1981). Glacial deposits in Gratiot County include lacustrine 

deposits, outwash, and till (Farrand and Bell, 1982; Vanlier, 

1963b). In general, lacustrine sand and gravel deposits domi‐

nate the southeastern portion of the county; while deposits in 

the central portion of the county are primarily lacustrine clay 

and silt. Outwash is composed of sand and gravel. In the Alma 

area, lenses of silt and clay are present in the outwash, and 

outwash deposits are capable of supplying moderate to large 

amounts of water to wells. Till may consist of clay, silt, sand, 

gravel, and boulders. In Gratiot County, fine to coarse‐grained 

till is present (Farrand and Bell, 1982).

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

According to the Public Water Supply database, the estimated 

transmissivity for glacial wells in Gratiot County ranges from 

approximately 1,270 to 5,050 ft2/day. In the Alma area, shal‐

low (0 to 30 ft in depth) lacustrine deposits are composed of 

sand and silt and may yield small supplies of water. The water 

from the shallow lacustrine deposits is generally hard and high 

in iron, and locally high in nitrate. Deeper lacustrine deposits 

in the Alma area also include sandy and silty clay deposits that 

act as a partially confining layer. These deposits do not supply 

water. The western portion of the Alma area is underlain with 

buried outwash, and this is the main source of water for the 

city. Transmissivity values were estimated from the coefficient 

of transmissibility for wells in buried‐outwash deposits using 

flow‐net analysis and pumping tests. These values range from 

1,537 to 2,673 ft2/day and 1,604 to 4,411 ft2/day, respectively. 

Water from the buried‐outwash deposits may be very hard and 

locally contain high sulfate concentrations (Vanlier, 1963b). 

In the Alma area, till contains large amounts of clay and is not 

very permeable (Vanlier, 1963b). A well completed in glacial 

till or outwash, located in Elwell, had a hydraulic conductiv‐

ity ranging from 8.6 x 10‐3 to 86.4 ft/day (Rogers and others, 

1996).

The bedrock underlies the glacial deposits. The bedrock 

surface of the county consists of “red beds”, the Grand River 

Formation, and the Saginaw Formation. In some areas of Gra‐

tiot County, Jurassic‐aged “red beds” are present beneath the 

glacial deposits, and consist of clay, mudstone, siltstone, and 

sandstone containing discontinuous beds of gypsum, and shaly 

sandstones. “Red beds” are considered to be a confining unit 

based on geophysical data (Westjohn and Weaver, 1998).

 The Grand River Formation is generally 50 to 100 

ft thick and is small in aerial extent within the State. It is 

primarily composed of coarse‐grained sandstone with layers 

of shale, carbonate, and coal (Catacosinos and others, 2001). 

The Grand River Formation is difficult to differentiate from 

the underlying Saginaw Formation. The Saginaw Formation 

contains interbeds of sandstone, siltstone, limestone, coal, and 

shale (Westjohn and Weaver, 1996a). The Saginaw Formation 

consists of shale, coal, sandy shale, sandstone, limestone, and 

sandstone. In the Alma area, the Saginaw Formation is 200 to 

350 ft thick and yields moderate supplies of water (Vanlier, 

1963b). The Parma Sandstone is often considered the basal 

unit of the Saginaw Formation, although the stratigraphic 

relationship is not clear between the Saginaw Formation, 

Parma Sandstone, and underlying Mississippian‐aged Bayport 

Limestone. The Parma Sandstone is composed of medium‐ to 

coarse‐grained sandstone, and is generally less than 100 ft 

thick (Cohee and others, 1951).

The Pennsylvanian bedrock above the Parma Sandstone 

can be divided into an upper sandstone aquifer and a lower 

confining unit. The Saginaw aquifer is in the sandstones 

from the Grand River and Saginaw Formations. The Saginaw 

aquifer ranges in thickness from less than 100 to 370 ft within 

the State (Westjohn and Weaver, 1996a). In Gratiot County, in 

an area where the Saginaw aquifer is 75 ft thick, based on an 

aquifer test, and the transmissivity and storage coefficient were 

estimated to be 320 ft2/day and 1.2 x 10‐4, respectively. Water 

from the Saginaw aquifer contains objectionable amounts 

of chloride in areas of Gratiot County (Vanlier, 1963b). The 

Saginaw aquifer yields both saline and fresh water in Gratiot 

County (Westjohn and Weaver, 1996c). The Saginaw confin‐

ing unit underlies the Saginaw aquifer. The Saginaw confining 

unit is approximately 50 to 100 ft thick within the county, and 

is mostly shale, with thin layers of discontinuous sandstone, 

siltstone, limestone, and coal. The permeable layers within the 

Saginaw confining unit appear to be isolated from the regional 

ground‐water‐flow system (Westjohn and Weaver, 1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

County Summaries  27
Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably 

in thickness from one area to another. The Bayport Lime‐

stone and Parma Sandstone appear to interfinger throughout 

the Michigan Basin (Westjohn and Weaver, 1996a). These 

units are hydraulically connected, and together they form 

the Parma‐Bayport aquifer. The Parma‐Bayport aquifer is 

approximately 100 to 150 ft thick within the Michigan Basin 

(Westjohn and Weaver, 1996a). Please note that due to the 

uncertainty of stratigraphic relationship between these units, 

in other reports this aquifer may be delineated differently. In 

Gratiot County, water from this aquifer may be saline or brine 

(Westjohn and Weaver, 1996c).

The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation is composed of sandstone, 

shale, limestone, and occasional dolomite. Gypsum and anhy‐

drite are also present in the formation. The lower permeability 

lithologies of the Michigan Formation are considered to be a 

confining unit that separates the Parma‐Bayport aquifer from 

the underlying Marshall aquifer. The Michigan confining unit 

is ranges from less than 50 to greater than 400 ft thick in the 

State (Westjohn and Weaver, 1996b).

 The Marshall Sandstone underlies the Michigan For‐

mation. The Marshall Sandstone consists of one or more 

stratigraphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzare‐

nite to sublitharenite. At the base of the Marshall Sandstone is 

a fine‐ to medium‐grained litharenite that ranges in thickness 

from 30 to 125 ft. Permeable sandstones in the Marshall Sand‐

stone comprise the Marshall aquifer. The Marshall aquifer 

ranges in thickness from 75 to greater than 200 ft within the 

State (Westjohn and Weaver, 1998). The Marshall Sandstone 

yields brine in Gratiot County (Westjohn and Weaver, 1996c).

Underlying the Marshall Sandstone is the Coldwater 

Shale. The Coldwater Shale consists of shale, sandstone, 

siltstone, and carbonates. It is considered a confining unit and 

ranges in thickness from 500 to 1,300 ft west to east across the 

State. (Westjohn and Weaver, 1996b).

Hillsdale County

Hillsdale County is in the southern portion of the Lower 

Peninsula of Michigan, and borders Indiana and Ohio. The 

St. Joseph, Kalamazoo, Upper Grand, Raisin, and Tiffin 

watersheds drain the county. According to the February 2005 

Wellogic database, approximately 63 percent of the wells in 

Hillsdale County are completed in the glacial deposits, and 

33 percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 4 percent of the wells in the 

county.

 Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

With the available information, glacial lithologies cannot be 

regionally correlated in the subsurface. This is likely due to 

the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). The glacial deposits in Hillsdale County consist 

of outwash, moraines, and till plains. Outwash is generally 

concentrated in the northwestern half of the county (Farrand 

and Bell, 1982). Outwash deposits consist of sand and gravel 

that is highly permeable. A glaciofluvial well, located in 

Jonesville had a hydraulic conductivity ranging from approxi‐

mately 2.9 to 285 ft/day (Rogers and others, 1996). Moraines 

and till plains are composed of till. Till is a mixture of clay, 

silt, sand, gravel, and boulders. In Hillsdale County, till is pri‐

marily medium to coarse grained. Till deposits occur through‐

out the county, but are dominant in the southeastern half of 

the county (Farrand and Bell, 1982). According to the Public 

Water Supply database, the estimated transmissivity for glacial 

wells in Hillsdale County ranges from approximately 6,685 to 

38,760 ft2/day.

Bedrock underlies the glacial deposits. The Marshall 

Sandstone and underlying Coldwater Shale form the bedrock 

surface of Hillsdale County. In general, the Marshall Sand‐

stone is a micaceous sandstone. In other areas of the State, the 

Marshall Sandstone has been described in more detail. The 

Marshall Sandstone consists of one or more stratigraphically 

continuous permeable sandstones. The upper sandstone is a 

quartzarenite to sublitharenite that is referred to as the Napo‐

leon Sandstone Member. A shale, siltstone, and/or carbonate 

layer separates the Napoleon Sandstone Member from the 

underlying lower Marshall sandstone. The lower Marshall 

sandstone is comprised of two units. The upper unit is gener‐

ally 50 to 125 ft of fine‐ to medium‐grained quartzarenite to 

sublitharenite. At the base of the Marshall Sandstone is a fine‐ 

to medium‐grained litharenite that ranges in thickness from 

30 to 125 ft. Permeable sandstones in the Marshall Sandstone 

comprise the Marshall aquifer. The Marshall aquifer ranges 

in thickness from 75 to greater than 200 ft within the State 

(Westjohn and Weaver, 1998). According to the Public Water 

Supply database, based on aquifer tests, the estimated trans‐

missivity for a well in the Marshall aquifer is approximately 

7,340 ft2/day. The Marshall Sandstone supplies freshwater in 

Hillsdale County (Westjohn and Weaver, 1996c).

 Coldwater Shale underlies the Michigan Formation and 

is composed of shale, sandstone, siltstone, and carbonates. 

The sandstone and siltstone layers in this unit thin to the west 

across the State, while carbonates become more abundant 

(Monnett, 1948). Coldwater Shale is generally considered to 

be a confining unit in areas of the State (Westjohn and Weaver, 

1996b). Locally, however, in Hillsdale County the Coldwater 

Shale yields small water supplies. According to the Public 

Water Supply database, based on aquifer tests, the estimated 

28  Summary of Hydrogeologic Conditions by County for the State of Michigan
transmissivity for a well in the Coldwater Shale is approxi‐

mately 535 ft2/day.

Houghton County

Houghton County is in the western Upper Peninsula of 

Michigan. The Ontonagon, Keweenaw Peninsula, Sturgeon, 

Dead‐Kelsey, and Lake Superior watersheds drain the county. 

The Sturgeon River drainage system and the East Branch of 

the Ontonagon River drain most of Houghton County (Doonan 

and others, 1970). According to the February 2005 Wellogic 

database, approximately 34 percent of the wells in Houghton 

County are completed in the glacial deposits, and 63 percent 

in the bedrock units. There is insufficient information to make 

this distinction for 3 percent of the wells in the county. Glacial 

aquifers may be locally confined. In the northern portion of the 

county, the thickness of the glacial deposits is extremely vari‐

able and igneous and metamorphic rocks are directly below 

the glacial deposits. Where glacial deposits are thick, small to 

moderate yields of water may be obtained. The igneous and 

metamorphic rocks yield more water where these rocks are 

highly fractured. In areas where the glacial deposits are greater 

than 50 ft thick and underlain by sedimentary bedrock, water 

yields are high (Twenter, 1981).

Post‐glacial deposits include stream and swamp depos‐

its, such as, muck, peat, sand, and gravel. Wells from stream 

deposits produce good quality water and enough water for 

domestic use. However, these wells may be tapping underlying 

deposits, or shallow wells may be supplied by surface water 

also (Doonan and others, 1970).

 Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

Glacial deposits include till, outwash, and lacustrine deposits. 

Ground moraines or till plains cover large areas of the county 

and range in thickness from 0 to 300 ft. In some areas, the till 

underlies outwash. Kames, kame terraces, eskers, and kettles 

are also present in the county, and composed of till that varies 

greatly in grain size. The Keweenaw Moraine occurs in central 

and southern Houghton County. The Keweenaw Moraine 

is composed of clay till and ranges in thickness from very 

thin to 360 ft thick. The sandy Marenisco Morainic Ridge 

crosses the southern portion of the county. In moraines and 

ground‐moraine wells, a layer of clay is usually penetrated 

before the deeper sand and gravel. These wells usually yield 

enough water for domestic use. Occasionally, the water may 

be high in iron. Outwash occurs in the southern part of the 

county and only as a thin deposit in the central portion of 

the county. These are predominantly sand and gravel. The 

southern outwash deposits are capable of yielding at least 

moderate supplies of good quality water. Lacustrine deposits 

are composed of layers of clay, sand, silt, and gravel. Lacus‐

trine deposits in the region are divided into clay rich units or 

sand rich units. Most of the lacustrine deposits are sand and 

supply more water than the clay deposits. Wells may also tap 

sand and gravel outwash deposits below the lacustrine deposits 

and the lacustrine clay deposits may act as local confining or 

semi‐confining layers. Wells completed in lacustrine deposits 

provide only moderately hard water that may have high iron 

content (Doonan and others, 1970). Using the specific capacity 

data from Doonan and others (1970), estimated transmissiv‐

ity values for the glacial aquifer range between 17 to 4,205 

ft2/day. According to the Public Water Supply database, based 

on aquifer tests the estimated transmissivity for glacial wells 

ranges from approximately 140 to 100,800 ft2/day.

The bedrock aquifer underlies the glacial aquifer. Esti‐

mated transmissivity values range between 0.3 to 1,200 ft2/day 

for the bedrock aquifer. These values were calculated using 

the specific capacity data of Doonan and others (1970). The 

surface expression of the bedrock surface in Houghton County 

trends northeast to southwest and the dip of the bedrock is 

toward the northwest. The Jacobsville Sandstone, composed of 

sandstone, shale, and conglomerate layers, forms the bedrock 

surface near the southeastern part of the county. Most of the 

water supply from bedrock aquifers in the county is obtained 

from Jacobsville Sandstone. Small to moderate yields of water 

are supplied from Jacobsville Sandstone wells. The quality of 

the ground water is generally acceptable. However, in deep 

wells, saline water may be tapped. The Freda Sandstone is 

exposed along the northwest portion of Houghton County and 

is arkosic sandstone interbedded with micaceous shale. Freda 

Sandstone is approximately 900 ft thick in Houghton County. 

Underlying the Freda Sandstone is the Nonesuch Shale, which 

is approximately 600 ft thick. The Copper Harbor Conglomer‐

ate is exposed at the bedrock surface in a thin strip slightly 

inland from the Freda sandstone and is composed of boulder to 

pebble‐sized clasts and arkose sandstone. The Copper Harbor 

Conglomerate includes two lava flows in northern Houghton 

County. Water supplies from the Copper Harbor Conglom‐

erate are small to moderate, and the water may be saline in 

areas. The Portage Lake Lava Series underlies the Copper 

Harbor Conglomerate, consists of basaltic and andesitic lavas 

interbedded with conglomerate, and is exposed at the bedrock 

surface trending northeast to southwest and terminates at 

the Keweenaw Fault. The southeastern portion of Houghton 

County contains an approximately 2 square mile area of the 

South Range Traps, a Lower Keweenawan basaltic lava flow. 

No information is available on the water supply from these 

rocks. The most southern portion of Houghton County is 

composed of Middle Precambrian slate and greywacke of the 

Animikie Series. Water supplies are small from the Animikie 

Series, and of good quality (Doonan and others, 1970).

Huron County

Huron County in the Lower Peninsula on the eastern side 

of the State and is partially bound by Lake Huron and Saginaw 

Bay. The Pigeon‐Wiscoggin, Birch‐Willow, Cass, and Lake 

Huron watersheds are included in the county. The eastern 

portion of the county is in the Thumb Uplands and the western 

portion of the county is located in the Saginaw Lowlands. The 

County Summaries  29
south central portion of the county is covered in rolling hills 

and is part of the Port Huron moraine, while the remainder of 

county is rather flat and slants toward Lake Huron and Sagi‐

naw Bay. The general direction of ground‐water flow is from 

southeast to northwest, towards Saginaw Bay (Sweat, 1992). 

According to the February 2005 Wellogic database, approxi‐

mately 6 percent of the wells in Huron County are completed 

in the glacial deposits, and 88 percent in the bedrock units. 

There is insufficient information to make this distinction for 

6 percent of the wells in the county. Sand and gravel glacial 

deposits, however, are not abundant or thick in the county, and 

the Marshall Sandstone is the principal aquifer (Sweat, 1992). 

Water quality may be an issue in areas of Huron County. 

Locally, the arsenic, cadmium, nitrate, and selenium concen‐

trations in ground water exceed USEPA maximum contami‐

nant levels (Sweat, 1992; Haack and Rachol, 2000c; Haack 

and Trecanni, 2000).

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a sequence of Pleistocene glacial 

deposits. With the available information, glacial lithologies 

cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). Glacial deposits range in thick‐

ness from less than 10 to 130 ft, and consist of till, outwash, 

and lacustrine deposits. Kames and drumlins are present in the 

south‐central portion of the county. Slightly south of the lacus‐

trine deposits, is a portion of the Port Huron Moraine that is 

composed of fine to coarse till with lenses of sand and gravel. 

Narrow portions of the morainal deposits, trending northeast 

to southwest, also occur on the eastern side of the county 

enclosed by the silt and clay lacustrine deposits. The sediment 

type of the morainal deposits may vary, however, clay‐rich tills 

constitute the majority of morainal deposits. An area of glacial 

outwash and post‐glacial alluvium is present in the south‐cen‐

tral portion of the county. A well completed in glacial till or 

outwash, located in Bad Axe, had a hydraulic conductivity 

ranging between 2.9 x 10‐2 to 285 ft/day (Rogers and others, 

1996). Lacustrine deposits of silt and clay cover the county 

surface in an arc pattern from east to west in the northern por‐

tion of the county. Sand and gravel lacustrine deposits occur 

along the shoreline, south of Wild Fowl Bay, in an area in the 

northwest part of the county, and in the south central portion 

of the county. A well completed in lacustrine deposits, located 

in Kinde, had a hydraulic conductivity ranging between 2.9 x 

10‐3 to 2.9 ft /day (Rogers and others, 1996).

Bedrock outcrops are present in Huron County, however 

in general, bedrock underlies glacial deposits. The bedrock 

surface in Huron County consists of the Saginaw Formation, 

Bayport Limestone, Michigan Formation, Marshall Sandstone, 

and Coldwater Shale. The Saginaw Formation forms the 

bedrock surface in the western part of the county, and thick‐

ness of the formation is up to 100 ft. The Saginaw Forma‐

tion is primarily shale and silty shale with layers of siltstone, 

fine‐grained sandstone, and coal. The Saginaw Formation is 

generally considered a confining unit in Huron County. How‐

ever, small yields of water may be obtained from the lenses of 

sandstone, generally in the western and southwestern por‐

tions of the county. These beds are usually confined by shale 

or silty shale. In Huron County, the water from the Saginaw 

Formation is usually hard and is generally only potable in the 

Caseville area (Sweat, 1992).

The Bayport Limestone underlies the Saginaw Forma‐

tion. The Bayport Limestone is a fossiliferous, cherty lime‐

stone, often with interbedded sandstone. The Bayport Lime‐

stone forms the bedrock surface in areas in the western part of 

the county. Locally, the Bayport Limestone may yield small 

amounts of good quality water. However, it is generally not 

considered an aquifer in the county (Sweat, 1992).

The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation is composed of sandstone, 

shale, limestone, and occasionally dolomite. Gypsum and 

anhydrite are present throughout the Michigan Formation but 

are more abundant in the lower portion of the formation and 

in the western part of the state. Locally, wells in the Michigan 

Formation may supply water, generally in the western and 

southwestern parts of the county. Often water from the forma‐

tion is saline. The Michigan Formation is generally considered 

a confining unit and not an aquifer. In the western portion of 

the county, water is high in dissolved sulfate probably due 

to the high amount of gypsum in the Michigan Formation. 

(Sweat, 1992).

 The Marshall Sandstone underlies the Michigan Forma‐

tion. The uppermost sandstone unit is the Napoleon Sandstone 

Member, and is up to 120 ft thick. The Napoleon Sandstone 

Member is composed of medium to coarse sandstone, which 

becomes finer near the base. Near the base, carbonaceous 

materials are present and layers of quartz pebbles occur all 

through the formation. The Napoleon Sandstone yields large 

amounts of good quality water, and is considered the principal 

aquifer in Huron County. Underneath the Napoleon Sandstone, 

the lower portion of the Marshall Sandstone consists of three 

sandstone layers. The upper unit of sandstone is not distinct, 

however, it can be recognized as the layer bound by silty, 

fine‐grained sandstone, with interbeds of shale. Below, the 

middle lower sandstone is coarse grained. Beds of fine‐grained 

sandstones and silty shales occur between the middle and 

lowest sandstone. The lowest sandstone is well cemented and 

composed of fine‐grained sandstone with lenses of pebbles 

and silty sand. The depth of the Marshall Sandstone increases, 

and the quality of water from the lower Marshall sandstone 

decreases in the southern and western ends of Huron County. 

However, potable water is obtained in some areas from the 

lower Marshall sandstone. Transmissivity for the Marshall 

Sandstone ranges from 7 to 1,300 ft2/day (Barton, 1995; 

Sweat, 1992). The Marshall Sandstone is not as productive 

of an aquifer in Huron County as it is in other counties in 

the State. High chloride concentrations are found in wells 

in southeastern Huron County from wells that tap the lower 

Marshall sandstone or the underlying Coldwater Shale (Sweat, 

1992).

30 Summary of Hydrogeologic Conditions by County for the State of Michigan
The contact between the Marshall Sandstone and the 

Coldwater Shale is transitional. Lenses of slaty sandstone 

and conglomerate are present in the Coldwater Shale, which 

is 1,000 to 1,200 ft thick in Huron County. Irregular beds of 

conglomerate occur in the upper portion of Coldwater Shale, 

near the contact with the overlying Marshall Sandstone. 

Fine‐grained, silty sandstone with layers of shale and siltstone 

comprise the upper portion of the Coldwater Shale where it 

outcrops in the eastern portion of Huron County. The Coldwa‐

ter Shale is generally considered a confining unit. However, 

small yields of water are obtained from Coldwater Shale along 

the eastern shore of Huron County. The water from Coldwater 

Shale has a high dissolved solids concentration, and is gener‐

ally only suitable for stock. Large quantities of water with‐

drawn from certain localities could cause an upward migration 

of brine from the Coldwater Shale (Sweat, 1992).

Ingham County

Ingham County is in the south‐central Lower Peninsula 

of Michigan. The Upper Grand watershed covers the majority 

of the county; a small area in southeastern Ingham County is 

in the Huron watershed. According to the February 2005 Wel‐

logic database, approximately 3 percent of the wells in Ingham 

County are completed in the glacial deposits, and 92 percent 

in the bedrock units. There is insufficient information to make 

this distinction for 5 percent of the wells in the county. Aqui‐

fers in the glacial and bedrock units provide water in Ingham 

County, but generally are not as highly productive in the north‐

eastern part of the county (Vanlier and others, 1973).

The glacial deposits in Ingham County range in thick‐

ness from less than 10 ft to over 300 ft. The glacial features in 

Michigan are the result of ice advances during late Wisconsin 

time (35,000 to 10,000 years before present). Glacial deposits 

are of three principal types: 1) a well‐sorted mixture of silt, 

sand, and gravel, such as valley outwash, outwash plains, 

eskers, kames, and buried outwash, deposited by streams 

of melt water draining from glaciers, 2) a layered sequence 

of silt, sand, and clay deposited in glacial lakes, and 3) an 

unsorted mixture of clay, silt, sand, gravel, and boulders, such 

as till, deposited directly from the melting ice (Vanlier and 

others, 1973). None of these deposits are regionally continu‐

ous (Mandle and Westjohn, 1989).

 Glacial deposits are the uppermost aquifer in Ingham 

County. Ground‐water flow in the glacial deposits is gener‐

ally from south to north, away from topographic divides and 

towards surface‐water bodies. Aquifers in the glacial deposits 

are composed of coarse alluvial and outwash materials. A 

large outwash area is south of Dansville in Ingham County. 

This outwash area varies in thickness and is primarily fine 

sand, although some is coarse sand and gravel. Long narrow 

ridges of sand and gravel, called eskers, are present in Ingham 

County. Esker deposits yield water to municipal wells in Wil‐

liamston and, historically, in Mason. Buried outwash deposits 

were formed as areas of outwash deposited by a preceding 

glacier were covered by a layer of till deposited during a later 

glacial advance. The most extensive area of buried outwash 

deposits are in the northern part of Ingham County. These 

areas of buried outwash are a potential source of water to 

wells; however, most wells in these areas are completed in 

bedrock aquifers because of the better quality water available. 

Till is present over much of the county and is generally not a 

source of water to wells. Locally the till may include thin beds 

of sand and gravel that are a source of water or may overlies 

bodies of sand and gravel that may yield moderate to large 

supplies of water (Vanlier and others, 1973).

The glacial deposits of Pleistocene age overlie Penn‐

sylvanian [and Upper Jurassic] bedrock units in Ingham 

County. Rocks of Triassic, [Lower and Middle] Jurassic, and 

Cretaceous age are missing (Mandle and Westjohn, 1989). 

The Jurassic “red beds” which separate Pennsylvanian rocks 

from glacial deposits in some areas of the Lower Peninsula, 

are either entirely absent or only marginally present in the 

Tri‐County region, which consists of Ingham, Clinton, and 

Eaton Counties (Westjohn and others, 1994). The “red beds” 

are often poorly consolidated or unconsolidated and consist 

of primarily clay, mudstone, siltstone, sandstone, shale and 

gypsum. The “red beds” are relatively impermeable and are 

considered a confining unit. The “red beds” impede the verti‐

cal flow of water between glacial‐drift and bedrock aquifers 

(Westjohn and others, 1994).

 Discontinuous lenses of sandstone, shale, coal, and lime‐

stone in the Pennsylvanian bedrock units have been formally 

subdivided into two formations. The uppermost massive, 

coarse‐grained sandstones form the Grand River Formation; 

all remaining Pennsylvanian rocks are considered part of the 

underlying Saginaw Formation (Mandle and Westjohn, 1989). 

In Ingham County, erosion removed most of the Grand River 

Formation, and as a result only a few large remnants remain 

(Vanlier and others, 1973). These assignments between forma‐

tions are somewhat uncertain, however, because no lithologic 

differences or stratigraphic horizons mark a change from one 

formation to the next (Westjohn and Weaver, 1996a). The 

Pennsylvanian bedrock unit ranges in thickness from 0 to over 

400 ft and is absent in the extreme eastern part of Ingham 

County.

The basal part of the Pennsylvanian Saginaw Forma‐

tion is considered to be the Parma Sandstone although the 

stratigraphic relationship is not clear between the Saginaw 

Formation, Parma Sandstone, and the underlying Bayport 

Limestone. The Parma Sandstone is composed of medium‐ to 

coarse‐grained sandstone and is generally less than 100 ft 

thick (Cohee and others, 1951). Interpretation of geophysi‐

cal logs indicates that the lower part of the Pennsylvanian 

rock sequence is predominantly shale, whereas the upper part 

is predominantly sandstone. Thus, the Pennsylvanian rocks 

younger than the Parma Sandstone can be divided into a lower 

confining unit and an upper sandstone aquifer (Westjohn and 

Weaver, 1996a).

 The Saginaw aquifer is in the water‐bearing sand‐

stones in the Grand River and Saginaw Formations. Most 

County Summaries  31
ground‐water flow in the Saginaw aquifer is from south to 

north, although a small amount is toward local pumping cen‐

ters. Flow across the western part of Ingham County, where 

the sandstone of the Saginaw Formation is very thin or absent, 

is minimal. The Saginaw aquifer is recharged principally by 

leakage from the glacial deposits. Ground water also dis‐

charges locally from bedrock to the glacial deposits beneath 

valleys of major streams (Holtschlag and others, 1996). The 

Grand River and Saginaw Formations act as a single hydro‐

logic unit, so the chemical characteristics of water in these for‐

mations are very similar. Nearly all wells tapping these forma‐

tions yield water that is suited to household needs. The water 

is generally hard or very hard and contains iron, although, in 

some localities, the Saginaw Formation yields soft water (Van‐

lier and others, 1973). Analyses of aquifer‐test data indicate 

a wide range of transmissivities within the Saginaw aquifer. 

Wood (1969) reported that pumping tests indicated a relatively 

constant permeability of the sandstone in the Saginaw Forma‐

tion of about 100 gpd/ft2 (13 ft/day). The permeability of the 

shale is more variable, ranging from 0.01 to 1.0 gpd/ft2 (0.001 

to 0.13 ft/day) (Wood, 1969). Transmissivities that range from 

130 to 2,700 ft2/day were reported for the Saginaw aquifer for 

the three‐county area of Clinton, Ingham, and Eaton Counties 

by Vanlier and Wheeler (1968). This range in transmissivi‐

ties reflects variations in the total thickness of the sandstone 

beds in the formation and variations in the permeability of the 

sandstone. Measured porosities and matrix‐controlled vertical 

hydraulic conductivities range from 4 to 34 percent and 0.0001 

to 55 ft/day, respectively (Westjohn and Weaver, 1996a).

Underlying the Saginaw Formation are beds of Missis‐

sippian age – (Bayport Limestone and Michigan Formation). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably in 

thickness from one area to another. The Bayport Limestone 

and Parma Sandstone appear to interfinger throughout the 

Michigan Basin. These units are hydraulically connected, and 

together they form the Parma‐Bayport aquifer (Westjohn and 

Weaver, 1996a). Please note that due to the uncertainty of 

stratigraphic relationship between these units, in other reports 

this aquifer may be delineated differently. The Michigan 

Formation is composed primarily of shale but includes beds of 

sandstone, limestone, and gypsum (Vanlier and others, 1973). 

The Michigan Formation is generally impermeable and con‐

sidered to be a confining unit (Westjohn and Weaver, 1998). 

Both the Bayport and Michigan Formations yield saline water 

where they are overlain by the Saginaw Formation. Wells 

tapping aquifers in these formations in Ingham County yield 

water too hard and too highly mineralized for domestic use 

(Stuart, 1945).

Ionia County

Ionia County is in the south‐central Lower Peninsula 

of Michigan. The Maple, lower Grand, upper Grand, and 

Thornapple watersheds drain Ionia County. According to the 

February 2005 Wellogic database, approximately 84 percent of 

the wells in Ionia County are completed in the glacial depos‐

its, and 14 percent in the bedrock units. There is insufficient 

information to make this distinction for 2 percent of the wells 

in the county.

Glacial aquifers consist of sand and gravel that are part 

of a thick sequence of Pleistocene glacial deposits. With the 

available information, glacial lithologies cannot be regionally 

correlated in the subsurface. This is likely due to the lateral 

and vertical heterogeneity of glacial deposits that resulted 

from a complex depositional history (Westjohn and others, 

1994). The glacial deposits in Ionia County are 0 to 500 ft 

thick. Glacial deposits in the county are primarily composed 

of till and outwash. Till may be found in moraines or till 

plains (Swanson, 1970). Moraines generally trend north to 

south in the county. Till is a poorly sorted mixture of clay, 

silt, sand, gravel, and boulders. The majority of till is fine‐ to 

medium‐grained in Ionia County (Farrand and Bell, 1982). 

Outwash is composed of sand and gravel and is generally 

the most productive glacial deposit. The glacial wells gener‐

ally tap buried outwash and primarily occur on till plains and 

moraines (Swanson, 1970). According to the Public Water 

Supply database, the estimated transmissivity for a glacial 

well is approximately 2,305 ft2/day. The quality of water from 

glacial wells varies. However, glacial wells may supply hard 

water that is high in iron (Swanson, 1970).

From youngest to oldest, the Jurassic “red beds”, Grand 

River Formation, Saginaw Formation, Bayport Limestone, and 

Michigan Formation form the bedrock surface in the county. 

The Jurassic “red beds” are also dispersed in portions of Ionia 

County. In Ionia County the “red beds” are often located on 

topographically high areas (Swanson, 1970). Where the “red 

beds” are present, the unit was deposited after bedrock and 

prior to glacial deposits. The Jurassic “red beds” generally 

range from 50 to 150 ft in thickness when present, and may 

be up to 200 ft thick. The “red beds” are often poorly consoli‐

dated or unconsolidated and consist primarily of clay, mud‐

stone, siltstone, sandstone, shale, and gypsum. The “red beds” 

are relatively impermeable and are considered a confining 

unit. The “red beds” impede the vertical flow of water between 

the glacial and bedrock aquifers (Westjohn and others, 1994). 

The water in the “red beds” is generally highly mineralized 

(Swanson, 1970).

The Pennsylvanian bedrock units in Ionia County include 

the Grand River and Saginaw Formations. The Grand River 

Formation is composed of primarily sandstone, but also 

contains shale and conglomerate. In Ionia County, the Grand 

River Formation is up to 100 ft thick, but is generally thinner. 

In Ionia County, the Saginaw Formation is up to 100 ft thick 

(Swanson, 1970). The Saginaw Formation consists of discon‐

tinuous layers of shale, coal, sandy shale, sandstone, lime‐

stone, and sandstone (Swanson, 1970; Westjohn and Weaver, 

1998). The Parma Sandstone is often considered the basal 

unit of the Saginaw Formation, although the stratigraphic 

relationship is not clear between the Saginaw Formation, 

Parma Sandstone, and underlying Mississippian‐aged Bayport 

32  Summary of Hydrogeologic Conditions by County for the State of Michigan
Limestone. The Parma Sandstone is composed of medium‐ to 

coarse‐grained sandstone, and is generally less than 100 ft 

thick (Cohee and others, 1951).

The Pennsylvanian bedrock above the Parma Sandstone 

can be divided into an upper sandstone aquifer and a lower 

confining unit. The Saginaw aquifer is in the sandstones 

from the Grand River and Saginaw Formations. The Saginaw 

aquifer ranges in thickness from less than 100 to 370 ft within 

the State (Westjohn and Weaver, 1996a). According to the 

Public Water Supply database, the estimated transmissivity for 

wells completed in the Grand River and Saginaw Formations 

in the county ranges from approximately 250 to 1,020 ft2/day. 

Hard to very hard water may be withdrawn from the Sagi‐

naw Formation (Swanson, 1970). The Saginaw aquifer yields 

both saline and fresh water in Ionia County (Westjohn and 

Weaver, 1996c). In Ionia County, where the Saginaw Forma‐

tion yields good quality water, the Saginaw Formation is used 

as an aquifer preferentially over the glacial aquifer (Swanson, 

1970). The Saginaw confining unit underlies the Saginaw 

aquifer. The Saginaw confining unit is approximately 50 to 

100 ft thick in the county, and is mostly shale, with thin layers 

of discontinuous sandstone, siltstone, limestone, and coal. The 

permeable layers within the Saginaw confining unit appear to 

be isolated from the regional ground‐water‐flow system (West‐

john and Weaver, 1996a).

 The Saginaw confining unit separates the Saginaw 

aquifer from the underlying Parma‐Bayport aquifer. Bedrock 

of Mississippian age underlies the Saginaw Formation. This 

includes the Bayport Limestone, Michigan Formation, Mar‐

shall Formation, and Coldwater Shale. The Bayport Limestone 

is a fossiliferous, cherty limestone, often with interbedded 

sandstone. In Ionia County, Bayport Limestone is 0 to 50 ft 

thick (Swanson, 1970). The Bayport Limestone and Parma 

Sandstone appear to interfinger throughout the Michigan 

Basin. These units are hydraulically connected, and together 

they form the Parma‐Bayport aquifer (Westjohn and Weaver, 

1996a). The Parma‐Bayport aquifer is approximately 100 to 

150 ft thick within the Michigan Basin. Please note that due 

to the uncertainty of stratigraphic relationship between these 

units, in other reports this aquifer may be delineated differ‐

ently. In Ionia County, the Parma‐Bayport aquifer yields saline 

water or brine (Westjohn and Weaver, 1996c).

The Michigan Formation underlies Bayport Limestone. 

The Michigan Formation consists of layers of sandstone, 

siltstone, anhydrite or gypsum, dolomite, limestone, and 

shale. The Michigan Formation is generally impermeable and 

considered a confining unit (Westjohn and Weaver, 1998). 

However, in Ionia County, the sandstone may provide small 

amounts of water to wells. The water obtained from the Michi‐

gan Formation is often mineralized from the abundance of 

gypsum in the formation. The water may also be saline. Good 

quality water may be obtained when the shallow sandstones 

of the Michigan Formation are significantly separated from 

gypsum units by shale layers (Swanson, 1970).

 The Marshall Sandstone underlies the Michigan For‐

mation. The Marshall Sandstone consists of one or more 

stratigraphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall aqui‐

fer ranges in thickness from 75 to greater than 200 ft within 

the State (Westjohn and Weaver, 1998). The Marshall aquifer 

is capable of supplying large quantities of water. The Marshall 

aquifer yields both saline water and brine in Ionia County 

(Westjohn and Weaver, 1996c). In Ionia County, shallower 

aquifers supply higher quality water than the Marshall aquifer.

Coldwater Shale underlies the Marshall Sandstone. 

Coldwater Shale consists of primarily shale with interbeds or 

lenses of sandstone, siltstone, and dolomite. Coldwater Shale 

is relatively impermeable and is considered a confining unit in 

most of Michigan and the bottom layer of the regional aquifer 

system (Westjohn and Weaver, 1998).

Iosco County

Iosco County is in the northeastern portion of the Lower 

Peninsula. The Saginaw Lowlands extend from the southwest 

to northwest along the southeastern portion of the county. 

The Lone Lake‐Ocqueoc, Au Sable, Au Gres‐Rifle, and Lake 

Huron watersheds drain through the county. According to the 

February 2005 Wellogic database, approximately 74 percent 

of the wells in Iosco County are completed in the glacial 

deposits, and 22 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 4 percent of the 

wells in the county. The bedrock wells are concentrated in the 

south‐central portion of the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional his‐

tory (Westjohn and others, 1994). The thickness of the glacial 

deposits ranges between 11 and 800 ft within the county, and 

generally decreases from north to south (Western Michigan 

University, 1981). Lacustrine deposits, till, and outwash com‐

pose the glacial deposits in Iosco County. Lacustrine deposits 

are the most abundant glacial deposit in the county, and are 

primarily coarse grained, except for in the southeast portion of 

the county, where the lacustrine deposits are fine grained. Till 

is primarily fine grained; however, in the north‐central portion 

of there is an area of county medium‐ and coarse‐grained till. 

The outwash deposits are composed of sand and gravel and 

occur in the northwestern portion of the county. Ice‐contact 

County Summaries  33
outwash is present in the central portion of the county (Farrand 

and Bell, 1982). According to the Public Water Supply data‐

base, the estimated transmissivity for glacial wells in Iosco 

County ranges from approximately 3,530 to 4,145 ft2/day.

In the northeastern portion of Iosco County, in the Au 

Sable watershed, is the location of the Wurtsmith Air Force 

base. In this area, the glacial aquifer is contaminated with 

volatile organic hydrocarbons. The generally unconfined 

aquifer consists of a medium to coarse‐grained sand with 

some gravel. The aquifer extends from the surface to 80 to 

30 ft underground, in the northern and western areas of the 

base, respectively. The average thickness of the aquifer is 65 

ft. In the northern part of the area, the aquifer also contains 

thin clay layers generally 5 to 15 ft below the surface. A clay 

unit underlies the glacial aquifer (Stark and others, 1983; 

Cummings and Twenter, 1986). The clay unit dips to the east 

and the exact thickness is unknown, but may be greater than 

250 ft in areas (Stark and others, 1983). Water levels in the 

aquifer at Wurtsmith Air Force base range between 10 to 25 ft 

below the ground surface, and fluctuate 1 to 3 feet annually. A 

ground‐water divide extends from the northeast to southwest 

across the base. Ground water flows to the east north of the 

divide and to the south, south of the divide (Stark and others, 

1983; Cummings and Twenter, 1986). The transmissivity and 

specific yield of the glacial aquifer at Wurtsmith Air Force 

Base was estimated from an aquifer test and ranges from 5,000 

to 20,000 ft2/day and 0.2, respectively. The hydraulic conduc‐

tivity was estimated from an aquifer test and specific capac‐

ity tests and ranges from 16 to 310 ft/day (Stark and others, 

1983).

Bedrock underlies the glacial deposits. The bedrock 

surface of Iosco County is composed the Michigan Formation, 

Marshall Sandstone, and Coldwater Shale (Milstein, 1987). 

The Michigan Formation consists of layers of sandstone, 

siltstone, anhydrite or gypsum, dolomite, limestone, and shale. 

The lower permeability lithologies of the Michigan Formation 

are considered a confining unit. The thickness of the Michigan 

confining unit ranges from less than 50 to 400 ft within the 

State (Westjohn and Weaver, 1998).

 The Marshall Sandstone underlies the Michigan For‐

mation. The Marshall Sandstone consists of one or more 

stratigraphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall 

aquifer ranges in thickness from 75 to greater than 200 ft 

within the State (Westjohn and Weaver, 1998). The Marshall 

Sandstone yields saline and fresh water in the southern and 

northern portion of Iosco County, respectively (Westjohn and 

Weaver, 1996c)

The Coldwater Shale underlies the Marshall Sandstone. 

The Coldwater Shale consists of primarily shale with interbeds 

or lenses of sandstone, siltstone, and dolomite. The Coldwa‐

ter Shale is considered a confining unit in most of Michigan 

(Westjohn and Weaver, 1996b).

Iron County

Iron County is in the southwestern portion of the Upper 

Peninsula of Michigan. The Ontonagon, Brule, Sturgeon, 

Michigamme, Menominee, Cedar‐Ford, and Upper Wisconsin 

watersheds drain Iron County. Ninety percent of the county’s 

surface is covered in glacial deposits. The rest is composed of 

post‐glacial swamp deposits and bedrock. The availability of 

ground water is not uniform within the county (Doonan and 

Hendrickson, 1967). According to the February 2005 Wel‐

logic database, approximately 69 percent of the wells in Iron 

County are completed in the glacial deposits, and 27 percent 

in the bedrock units. There is insufficient information to make 

this distinction for 4 percent of the wells in the county.

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

The glacial deposits in Iron County consist of moraines and till 

plains, composed primarily of till, and outwash deposits. The 

thickness of the glacial deposits ranges from 0 to hundreds 

of feet thick. Glacial deposits in the county include till and 

outwash. In general, the glacial deposits can be divided into 

two sections in Iron County which were deposited from differ‐

ent glacial events. The glacial deposits in the southern portion 

of the county are primarily older and lack terminal moraines. 

Also in the south, eskers and drumlins are common with 

the older glacial deposits overlain in some areas by younger 

glacial deposits. The northern part of the county consists of 

the younger glacial deposits, but lacks drumlins. Lenses of 

sand and gravel occur locally in drumlins that are primarily 

composed of till. Eskers are composed of till, but tend to be 

richer in boulders (Stuart and others, 1948). Moraines are gen‐

erally composed of till, consisting of boulders, cobbles, gravel, 

sand, silt, and clay. Small to moderate yields of water may be 

obtained from wells completed in moraine deposits. The water 

is moderately hard to hard and contains small to moderate 

amounts of iron. Till plains in Iron County, generally consist 

of sandy, clayey till with boulders. Till‐plain wells generally 

yield small supplies of water that is low in iron and is moder‐

ately hard to hard. The largest outwash plain is located south 

of Crystal Falls. Narrower areas of outwash also occur in the 

county. The outwash is comprised of mostly sand and gravel. 

Specific capacities range from 0.1 to 28 gal/min/ft in the 

glacial outwash. Outwash wells generally provide the largest 

yields of water. The water from outwash wells is moderately 

hard to very hard, and a few wells have high iron content 

(Doonan and Hendrickson, 1967). According to Stuart and 

others (1948), the estimated transmissivity for the glacial wells 

34  Summary of Hydrogeologic Conditions by County for the State of Michigan
from aquifer tests range from approximately 10,000 to 32,000 

ft2/day. The storage coefficient ranges from 0.0007 to 0.207 in 

the glacial aquifer (Stuart and others, 1948). According to the 

Public Water Supply database, the estimated transmissivity for 

glacial wells ranges from approximately 725 to 53,475 ft2/day.

Bedrock in Iron County is mostly igneous and metamor‐

phic Precambrian rocks. There are outcrops along the Michi‐

gamme River and dispersed throughout the county. In general, 

bedrock wells only supply small quantities of water that is 

moderately hard to hard, and contain low amounts of iron 

(Doonan and Hendrickson, 1967).

Isabella County

Isabella County is in the central part of the Lower Penin‐

sula of Michigan. The Tittabawassee, Pine, and Lower Grand 

River watersheds drain Isabella County. According to the 

February 2005 Wellogic database, approximately 99 percent 

of the wells in Isabella County are completed in the glacial 

deposits, and less than 1 percent in the bedrock units. There is 

insufficient information to make this distinction for 1 percent 

of the wells in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). Glacial deposits are 

approximately 150 to 600 ft thick in Isabella County (Western 

Michigan University, 1981). The glacial deposits are com‐

posed of till, outwash and lacustrine deposits. The till deposits 

are generally medium‐ to coarse‐textured material but can 

range from clay to boulder size. These deposits are found in 

the three separate moraines that are along the west side of the 

county. In between those three moraines are glacial outwash 

deposits. These outwash deposits are composed of sand and 

gravel material. Both sand and gravel, as well as, clay and silt 

dominated lacustrine deposits are present in eastern edge of 

the county (Farrand and Bell, 1982). According to the Public 

Water Supply database, the estimated transmissivity for glacial 

wells ranges from approximately 1,630 to 20,160 ft2/day.

The bedrock surface of Isabella County is composed of 

the Jurassic “red beds” and the Saginaw Formation (Milstein, 

1987) which both underlie the glacial deposits. The Jurassic 

“red beds” are generally 50 to 150 ft thick (Westjohn and oth‐

ers, 1994). The “red beds” occur primarily in the southern por‐

tion of the county (Milstein, 1987). The “red beds” consist of 

red clay, mudstone, siltstone, and sandstone, and also include 

gray‐green shale, gypsum, and mudstone (Shaffer, 1969). The 

“red beds” are considered as a confining unit in Michigan 

(Westjohn and others, 1994). Where the “red beds” are pres‐

ent, the Saginaw Formation underlies the Jurassic deposits.

Interbedded sandstone, siltstone, shale, coal, and lime‐

stone compose the Saginaw Formation. The Saginaw aquifer 

consists of hydraulically connected sandstones in the Saginaw 

Formation (Westjohn and Weaver, 1998). Within the State, the 

Saginaw aquifer ranges between less than 100 to 370 ft thick, 

and yields both fresh and saline water. The Saginaw aquifer 

yields fresh water in the southeastern corner of the county. In 

the rest of Isabella County, the Saginaw aquifer yields saline 

water (Westjohn and Weaver, 1996c). The Saginaw confining 

unit underlies the Saginaw aquifer. The Saginaw confining 

unit is approximately less than 100 to 240 ft thick within the 

State, and is mostly shale, with thin layers of discontinuous 

sandstone, siltstone, limestone, and coal. The permeable layers 

within the Saginaw confining unit appear to be isolated from 

the regional ground‐water‐flow system (Westjohn and Weaver, 

1996a).

Jackson County

Jackson County is in the southern portion of the Lower 

Peninsula of Michigan. The Kalamazoo, Upper Grand, Huron, 

and Raisin watersheds drain the county in the southwestern, 

north and central, eastern edge, and southeastern portions of 

the county, respectively. The Upper Grand watershed covers 

the majority of the county, while the Huron watershed drains 

a small portion of the county on the eastern side. According 

to the February 2005 Wellogic database, approximately 12 

percent of the wells in Jackson County are completed in the 

glacial deposits, and 74 percent in the bedrock units. There is 

insufficient information to make this distinction for 14 percent 

of the wells in the county. The main bedrock aquifers are the 

Saginaw and Marshall aquifers (Vanlier, 1968).

In the Michigan basin, glacial aquifers consist of sand 

and gravel that is part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). The glacial deposits in Jackson 

County are generally 100 ft thick or less. Glacial deposits 

include outwash, moraines, and till plains (Vanlier, 1968). In 

Jackson County, there is an abundance of outwash interspersed 

throughout the county (Vanlier, 1968; Farrand and Bell, 1982). 

Glacial outwash is generally very permeable and composed 

of sand and gravel. Moraines and till plains are composed of 

till. Till is mixture of clay, silt, sand, and gravel, which often 

has lower permeability (Vanlier, 1968). The till in Jackson 

County is medium to coarse grained (Farrand and Bell, 

1982). Moraines and till plains may contain lenses of outwash 

(Vanlier, 1968). Glacial wells may supply water that is hard to 

very hard and contain objectionable amounts of iron (Vanlier, 

1968).

Bedrock underlies the glacial deposits. The Saginaw 

Formation, Bayport Limestone, Michigan Formation, Marshall 

Sandstone, and Coldwater Shale form the bedrock surface of 

Jackson County. The Saginaw Formation contains interbeds of 

discontinuous sandstone, siltstone, limestone, coal, and shale 

County Summaries  35
(Westjohn and Weaver, 1998). The sandstone in the Saginaw 

Formation is the Saginaw aquifer. The Saginaw aquifer ranges 

in thickness from less than 100 to 370 ft in thickness in the 

State. The Saginaw aquifer is utilized in the northern portion 

of Jackson County (Westjohn and Weaver, 1998). Here, the 

Saginaw aquifer yields soft to very hard, fresh water (Vanlier, 

1968; Westjohn and Weaver, 1996c). The Saginaw confining 

unit underlies the Saginaw aquifer. The Saginaw confining 

unit is approximately 50 ft in thickness and is mostly shale, 

with thin layers of sandstone, siltstone, limestone, and coal 

(Westjohn and Weaver, 1996a).

 The Saginaw confining unit separates the Saginaw 

aquifer from the underlying Parma‐Bayport aquifer. The 

Parma Sandstone is often considered the basal unit of the Sagi‐

naw Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably 

in thickness from one area to another. The Bayport Lime‐

stone and Parma Sandstone appear to interfinger throughout 

the Michigan Basin (Westjohn and Weaver, 1996a). These 

units are hydraulically connected, and together they form 

the Parma‐Bayport aquifer (Westjohn and Weaver, 1996a). 

The Parma‐Bayport aquifer is approximately 100 to 150 ft 

thick within the Michigan Basin. Please note that due to the 

uncertainty of stratigraphic relationship between these units, 

in other reports this aquifer may be delineated differently. 

Not much information is available on this aquifer because 

it is not often used as a water supply in the State (Westjohn 

and Weaver, 1996a). In Jackson County, the water from the 

Parma‐Bayport aquifer may be saline (Westjohn and Weaver, 

1996c).

 The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation consists of layers of sand‐

stone, siltstone, anhydrite or gypsum, dolomite, limestone, 

and shale. The lower permeability lithologies of the Michigan 

Formation are considered a confining unit that separates the 

Parma‐Bayport aquifer from the underlying Marshall aquifer. 

The thickness of the Michigan confining unit ranges from 

less than 50 to 400 ft within the State (Westjohn and Weaver, 

1998).

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone consists of one or more strati‐

graphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall aqui‐

fer ranges in thickness from 75 to greater than 200 ft within 

the State (Westjohn and Weaver, 1998). The Marshall aquifer 

generally supplies water to the southern portion of Jackson 

County (Vanlier, 1968). Transmissivity values in Jackson 

County are between 7,500 and 29,000 ft2/day. The Marshall 

aquifer yields fresh water in the majority of Jackson County, 

except in the north‐central portion of the county where it 

yields saline water (Westjohn and Weaver, 1996c).

Underlying the Marshall Sandstone is the Coldwater 

Shale. The Coldwater Shale consists of shale, sandstone, 

siltstone, and carbonates. This is considered to be a confining 

unit and ranges in thickness, from east to west across the State, 

between 500 and 1,300 ft thick (Westjohn and Weaver, 1998).

Kalamazoo County

Kalamazoo County is in the southwestern Lower Penin‐

sula of Michigan. The Kalamazoo, Paw Paw, and St. Joseph 

watersheds cross the county. The Kalamazoo River drains 

the northern two‐thirds, the Paw Paw River drains a small 

part of the western section, and the St. Joseph River drains 

the remaining southern part of the county. According to the 

February 2005 Wellogic database, approximately 95 percent 

of the wells in Kalamazoo County are completed in the glacial 

deposits, and 2 percent in the bedrock units, which are located 

primarily in the northeastern portion of the county. There is 

insufficient information to make this distinction for 3 percent 

of the wells in the county.

Glacial deposits range in thickness from less than 40 ft 

along the Kalamazoo River to more than 600 ft in the western 

part of the county. The glacial deposits in Kalamazoo County 

are composed of till plains, upland moraines, outwash plains, 

and downcut glacial drainage channel (Rheaume, 1990). 

Monaghan and others (1983) describe the till as varying from 

mostly clay to primarily sand. Two morainic systems are 

present in Kalamazoo County, the Tekonsha and Kalamazoo 

Moraines. The Tekonsha Moraine is just south of the Kal‐

amazoo River Valley from Galesburg east toward Calhoun 

County and consists of massive to poorly bedded, coarse sand 

to sandy‐clay till, and at places, as massive to poorly bedded 

sand and gravel containing boulders and cobbles (Monaghan 

and others, 1983). The Kalamazoo Moraine is along the west‐

ern edge of the county and rises more than 100 ft above the 

outwash plain in some places (Rheaume, 1990). The moraine 

forms one of the longest continuous ridges in southern Michi‐

gan and has been traced for a distance of over 80 mi (Leverett 

and Taylor, 1915). Monaghan and others (1983) describe the 

Kalamazoo Moraine as sandy to very sandy till and massive to 

poorly bedded cobbly sand. The outwash plains are referred to 

as the Climax‐Scotts outwash plain and the Galesburg‐Vicks‐

burg outwash plain and consist of medium‐ to very‐coarse 

sand and gravel (Monaghan and others, 1983). The downcut 

glacial drainage channel was formed in the area of the Kal‐

amazoo River and consists of medium‐ to very‐coarse sand 

36  Summary of Hydrogeologic Conditions by County for the State of Michigan
and gravel with some layers of clayey silt (Monaghan and 

others, 1983). Kehew and others (1999) studied tunnel valleys 

in southwestern Michigan. Tunnel valleys are formed when 

subglacial water, which is often under immense hydrostatic 

pressure, seeks an outlet (Sugden and John, 1976). Tunnel val‐

leys in the Kalamazoo County area may be important relative 

to aquifer occurrence.

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

Aquifers underlying the outwash plains and the downcut gla‐

cial drainage channels, which together cover about two‐thirds 

of the county, are the most productive (Rheaume, 1990). Allen 

and others (1972) identified an upper unconfined aquifer 

throughout most of the county and one to two lower semicon‐

fined aquifers over about one‐third of the county. The ground 

water is generally of high quality, although the water is hard 

and generally has objectionably high iron content (Allen and 

others, 1972). At many locations, the hydraulic connection is 

good enough that, under pumping conditions, water will move 

readily between aquifers. The transmissivity values for the 

sand and gravel aquifers range from 1,250 to 57,200 ft2/day.

Bedrock underlies the glacial deposits. The bedrock sur‐

face of the county consists primarily of the Coldwater Shale, 

with the Marshall Formation comprising the upper bedrock 

surface in the northeastern part of the county. The Coldwater 

Shale is 500 ft or more thick in the Kalamazoo County area 

and gently dips northeastward (Deutsch and others, 1960). The 

Coldwater Shale primarily is composed of shale that contains 

limestone and clayey limestone in some areas (Rheaume, 

1990). Water from the Coldwater Shale unit is highly mineral‐

ized and yields are small; therefore, the Coldwater Shale is not 

generally used for water supply. The Coldwater Shale grades 

upward into the Marshall Formation. The Marshall Forma‐

tion directly overlies the Coldwater shale in the northeastern 

part of Kalamazoo County, and has been eroded away in 

the rest of the county (Deutsch and others, 1960). The Mar‐

shall Formation in the county is composed of gray to white 

sandstone that consists of rounded to subangular grains of 

very fine to medium sand in alternating soft and hard layers 

(Passero, 1983). The Marshall aquifer consists of one or more 

stratigraphically continuous permeable sandstones. In areas 

where the Marshall aquifer consists of two or more sand‐

stones, these permeable strata typically are separated by beds 

of siltstone, shale and (or) carbonate (Westjohn and Weaver, 

1996b). A range of transmissivity values, 0 to 15,000 ft2/day, 

were estimated for the upper sandstone aquifer in the Marshall 

Sandstone in nearby Calhoun County from constant hydraulic 

conductivities of 150 ft/day and a thickness from 0 to 100 ft. 

Also, in Calhoun County, a pumping test was performed on 

the lower sandstone aquifer. A transmissivity of 25,000 ft2/day 

and a storage coefficient of 1.5 x 10‐5 were estimated from 

the aquifer test. Transmissivity values ranging from 3,000 to 

27,000 ft2/day were estimated for the lower sandstone aquifer 

from constant hydraulic conductivities of 550 ft/day and a 

thickness from 5 to 50 ft (Grannemann and Twenter, 1985). 

Sufficient quantities of water can be withdrawn from the Mar‐

shall Formation for domestic supply where it is overlain by 

glacial deposits in Kalamazoo County.

Kalkaska County

Kalkaska County is located in the northwestern portion of 

the Lower Peninsula of Michigan. The Muskegon, Manistee, 

Boardman‐Charlevoix, and Au Sable watersheds cross the 

county. According to the February 2005 Wellogic database, 

approximately 99 percent of the wells in Kalkaska County are 

completed in the glacial deposits, and 0 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 1 percent of the wells in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). Generally, the glacial 

deposits in Kalkaska County range from 401 to 600 ft thick. 

However, the thickness of the glacial deposits spans from 201 

to 1,000 ft in the county (Western Michigan University, 1981). 

Glacial deposits in Kalkaska County include outwash, till, and 

lacustrine deposits. The most abundant glacial deposit in the 

county is sand and gravel outwash. Ice‐contact outwash that is 

dominated by poorly sorted sand and gravel is present in the 

western and southern part of the county. Coarse‐grained till is 

found in a moraine that trends southwest to northeast in por‐

tions of the western half of the county. The northwest corner 

of Kalkaska County is composed of sand and gravel lacustrine 

deposits. Post‐glacial dune sand deposits also are present in 

areas of the county, and are small in aerial extent (Farrand 

and Bell, 1982). Glacial wells in the county, according to the 

Public Water Supply database, have estimated transmissivi‐

ties from aquifer tests that range from approximately 12,400 

to 33,954 ft2/day. Bedrock underlies the glacial deposits in the 

county, but is not currently used for water supply.

Kent County

Kent County is in the western south‐central Lower Penin‐

sula of Michigan. The Kalamazoo, Lower Grand, Thornapple, 

and Muskegon watersheds drain the county. Water supplies 

are obtained from surface water and ground water. Accord‐

ing to the February 2005 Wellogic database, approximately 

94 percent of the wells in Kent County are completed in the 

glacial deposits, and 4 percent in the bedrock units. There is 

insufficient information to make this distinction for 2 percent 

of the wells in the county.

 In the Michigan Basin, the glacial aquifer consists of 

sand and gravel that is part of a thick sequence of Pleisto‐

cene glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

County Summaries  37
glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). The thickness of glacial 

deposits ranges from 11 to 800 ft in Kent County. However, 

the majority of glacial deposits range from 201 to 400 ft in 

thickness (Western Michigan University, 1981). The glacial 

deposits in the county include till, outwash, and lacustrine 

deposits. Till occurs in moraines and till plains, and are inter‐

spersed on the surface throughout the county (Stramel and 

others, 1954; Farrand and Bell, 1982). Till is composed of fine 

to coarse‐grained material, including silt, sand, gravel, and 

boulders; however, the majority of the till in Kent County is 

medium‐grained (Farrand and Bell, 1982). In the Grand Rap‐

ids area, moraines and till‐plain deposits may provide small 

quantities of water (Stramel and others, 1954). According to 

the Public Water Supply database, the estimated transmissiv‐

ity for wells tapping medium‐textured glacial till ranges from 

approximately 2,350 to 48,845 ft2/day in Kent County. Out‐

wash is the most permeable of the glacial deposits, and con‐

sists of sand and gravel. Outwash consists of sand and gravel, 

and also is distributed throughout the county (Farrand and 

Bell, 1982). In the Grand Rapids area, the outwash ranges in 

thickness from 0 to 90 ft. According to the Public Water Sup‐

ply database, the estimated transmissivity for wells completed 

in the outwash in the county, ranges from approximately 5,700 

to 962,640 ft2/day. Stramel and others (1954) observed thin 

layers of lacustrine deposits in the Grand Rapids area. In the 

area, lacustrine deposits consist of clay and fine‐grained sand, 

and may be underlain by sand and gravel. In the Grand Rapids 

area, water from the glacial wells may be hard (Stramel and 

others, 1954). Atrazine has been modeled to leach into the 

shallow aquifer in areas of Kent County (Holtschlag and 

Luukkonen, 1996; 1998).

Bedrock underlies the glacial deposits. The Jurassic “red 

beds” form the bedrock surface in portions of Kent County. 

The Jurassic “red beds” generally range between 50 to 150 

ft in thickness when present, and may be up to 200 ft thick. 

Where the “red beds” are present, the unit occurs underly‐

ing glacial deposits and overlying the bedrock surface. The 

“red beds” are often poorly consolidated or unconsolidated 

and consist primarily of clay, mudstone, siltstone, sandstone, 

shale, and gypsum. The “red beds” are relatively imperme‐

able and are considered a confining unit. However, locally 

in the county, the “red beds” may supply small quantities of 

water. According to the Public Water Supply database, the 

estimated transmissivity for a well completed in the “red beds” 

is approximately 850 ft2/day. The “red beds” impede the verti‐

cal flow of water between glacial and bedrock aquifers. In the 

west‐central portion of the State, the “red beds” are usually 

present over the saline‐water‐bearing Pennsylvanian rocks 

(Westjohn and others, 1994).

From northeast to southwest the Saginaw Formation, 

Bayport Limestone, Michigan Formation, and Marshall 

Sandstone form the remainder of the bedrock surface, gener‐

ally trending northwest to southeast, in the county. Bedrock 

units dip to the northeast. The Saginaw Formation consists of 

shale, coal, sandy shale, sandstone, limestone, and sandstone. 

The Saginaw aquifer consists of the sandstones in the Saginaw 

Formation (Westjohn and Weaver, 1998). The water from the 

Saginaw aquifer is usually high in iron and hard (Stramel and 

others, 1954). The Saginaw aquifer yields saline water in Kent 

County (Westjohn and Weaver, 1996c). The Saginaw confin‐

ing unit underlies the Saginaw aquifer. The Saginaw confin‐

ing unit is less than 100 to 240 ft thick within the State, and 

is mostly shale, with thin layers of discontinuous sandstone, 

siltstone, limestone, and coal. The permeable layers within the 

Saginaw confining unit appear to be isolated from the regional 

ground‐water‐flow system (Westjohn and Weaver, 1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably 

in thickness from one area to another. The Bayport Lime‐

stone and Parma Sandstone appear to interfinger throughout 

the Michigan Basin (Westjohn and Weaver, 1996a). These 

units are hydraulically connected, and together they form 

the Parma‐Bayport aquifer (Westjohn and Weaver, 1996a). 

The Parma‐Bayport aquifer is approximately 100 to 150 ft 

thick within the Michigan Basin. Please note that due to the 

uncertainty of stratigraphic relationship between these units, 

in other reports this aquifer may be delineated differently. In 

Plainfield Township, the Bayport Limestone is known to sup‐

ply large quantities of water (Vanlier, 1968).

The Michigan Formation underlies the Bayport Lime‐

stone. Shale and gypsum are the primary constituents of the 

Michigan Formation, however, lenses of sandstone and lime‐

stone are also present (Stramel and others, 1954). The Michi‐

gan Formation has lower permeability, and is generally consid‐

ered a confining unit within the State (Westjohn and Weaver, 

1996b). In the central‐western and southwestern portion of the 

county, including the Grand Rapids area, the Michigan Forma‐

tion may supply small to moderate amounts of highly mineral‐

ized water (Stramel and others, 1954; Vanlier, 1968).

 The Marshall Sandstone underlies the Michigan For‐

mation. The Marshall Sandstone consists of one or more 

stratigraphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall aqui‐

fer ranges in thickness from 75 to greater than 200 ft within 

38  Summary of Hydrogeologic Conditions by County for the State of Michigan
the State (Westjohn and Weaver, 1998). The Marshall aquifer 

is capable of supplying large quantities of water. According 

to the Public Water Supply database, the estimated transmis‐

sivity for wells completed in the Marshall aquifer ranges from 

approximately 560 to 8,635 ft2/day. In the Grand Rapids area, 

water from the Marshall aquifer is often used for industrial 

purposes (Stramel and others, 1954). The Marshall Sandstone 

yields fresh and saline water, and brine in Kent County (West‐

john and Weaver, 1996c). Water from Marshall Sandstone is 

hard, mineralized, and may contain hydrogen sulfide gas in 

the northern portion of the Grand Rapids area. These effects 

decrease towards the south (Stramel and others, 1954).

The Coldwater Shale underlies the Marshall Sandstone. 

The Coldwater Shale consists of primarily shale with interbeds 

or lenses of sandstone, siltstone, and dolomite. The Coldwater 

Shale is relatively impermeable and water from the unit is 

highly mineralized (Stramel and others, 1954).

Keweenaw County

Keweenaw County is in the western Upper Peninsula 

of Michigan. The Keweenaw Peninsula and Lake Superior 

watersheds drain the county. Keweenaw County does not have 

abundant supplies of ground water (Doonan and others, 1970). 

According to the February 2005 Wellogic database, approxi‐

mately 36 percent of the wells in Keweenaw County are com‐

pleted in the glacial deposits, and 60 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 4 percent of the wells in the county.

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

The glacial deposits range in thickness from 0 to 312 ft in the 

county. The glacial deposits consist of morainal, lacustrine, 

and outwash deposits. Ground moraines or till plains cover 

large areas of the county and range in thickness from 0 to 300 

feet. Kames, kame terraces, eskers, and kettles are present 

in the county and vary greatly in grain size. In some areas, 

the till underlies outwash. In moraines and ground moraine 

wells, a layer of clay is usually penetrated before the deeper 

sand and gravel. These wells usually yield enough water for 

domestic use. Occasionally, the water may be high in iron. 

Outwash occurs in a small portion of the county. These are 

predominantly sand and gravel deposits. Lacustrine deposits 

are composed of layers of clay, sand, silt, and gravel. Lacus‐

trine deposits in the Keweenaw County are predominantly 

sand. Wells in sandy lacustrine deposits may also tap sand and 

gravel outwash deposits below the lacustrine deposits. Lacus‐

trine wells may provide moderately hard water that may have 

high iron content (Doonan and others, 1970). According to the 

Public Water Supply database, the estimated transmissivity for 

glacial wells ranges from approximately 1,440 to 1,800 ft2/day. 

Water from the glacial aquifer may be high in iron content and 

is not saline (Doonan and others, 1970).

The bedrock aquifer provides a large portion of the 

ground‐water supply in Keweenaw County. Using the specific 

capacity data from Doonan and others (1970), an estimated 

transmissivity for the bedrock aquifer ranges between 4 and 

442 ft2/day. In general, the water from the bedrock aquifer is 

soft to moderately hard and may contain high iron concentra‐

tions. In a few areas, the water from bedrock wells is saline 

(Doonan and others, 1970). The surface expression of the bed‐

rock surface in Keweenaw County generally trends northeast 

to southwest and the dip of the bedrock is northwest, except 

on Isle Royale where the dip is southeast. The difference in 

the bedrock dip is the result of the two limbs of a syncline that 

runs beneath the western portion of Lake Superior.

 The Jacobsville Sandstone forms the bedrock surface 

near the eastern part of the county. Most of the bedrock wells 

in the county obtain water from the Jacobsville Sandstone, 

composed of sandstone, shale, and conglomerate layers. Small 

to moderate yields of water are supplied from Jacobsville 

sandstone wells. The quality of the ground water is gener‐

ally acceptable; however, saline water may be tapped in deep 

wells.

 The Freda Sandstone forms the bedrock surface along 

the north and northwestern portion of Keweenaw County 

and along the southeastern shore of Isle Royale. The Freda 

Sandstone is an arkose sandstone interbedded with micaceous 

shale. Underlying the Freda Sandstone is the Nonesuch Shale, 

which is approximately 600 feet thick. Water supplies from the 

Freda Sandstone and Nonesuch shale are small and tend to be 

saline.

The Copper Harbor Conglomerate includes two lava 

flows in Keweenaw County, and is exposed on Isle Royale 

and the northern and western shores of Keweenaw County. 

The Copper Harbor Conglomerate is composed of boulder to 

pebble‐size clasts and arkose sandstone. Water supplies from 

the Copper Harbor Conglomerate are small to moderate and 

the water may be saline in areas.

The Portage Lake lava flows form the bedrock surface 

along the northern shore of Isle Royale and north and north‐

west of the Jacobsville sandstone. The Portage Lake Lava 

Series consists of basaltic and andesitic lavas interbedded with 

conglomerate. Salinity in the water increases with depth in 

the Portage Lake lava flow (Doonan and others, 1970). The 

Portage Lake Volcanics form the bedrock surface at Win‐

digo, located in Isle Royale National Park. Bailing tests were 

performed on two bedrock test wells in this area and yielded 

0.1 and 0.5 gal/min. A pumping test was also performed on 

another bedrock test well, which had a yield near 1 gal/min. 

These wells were abandoned and grouted. Wells in the Portage 

Lake Volcanics at Windigo did not yield sufficient amounts of 

water (Grannemann and Twenter, 1982).

Lake County

Lake County is in the western north‐central Lower Pen‐

insula of Michigan. The Pere Marquette‐White, Muskegon, 

and Manistee watersheds drain the county. According to the 

February 2005 Wellogic database, approximately 98 percent of 

County Summaries  39
the wells in Lake County are completed in the glacial depos‐

its, and 0 percent in the bedrock units. There is insufficient 

information to make this distinction for 2 percent of the wells 

in the county.

In the Michigan Basin, the glacial aquifer consists of sand 

and gravel that is part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). In Lake County, glacial deposits 

are 201 to 1,000 ft thick. The thickness of the deposits gener‐

ally increases to the northeast in the county (Western Michigan 

University, 1981). Glacial deposits in Lake County consist of 

primarily outwash and till. Outwash is interspersed through‐

out the county and composed of primarily sand and gravel. 

Coarse‐grained till in moraines and till plains are located 

sporadically throughout the county, and cover the southeastern 

and southwestern corners of the county (Farrand and Bell, 

1982). According to the Public Water Supply database, the 

estimated transmissivity for glacial wells ranges from approxi‐

mately 1,960 to 21,270 ft2/day. Bedrock underlies the glacial 

deposits, but is not currently used for ground‐water supplies.

Lapeer County

Lapeer County is in the eastern south‐central Lower 

Peninsula of Michigan. The Flint, Cass, St. Clair, and Clinton 

watersheds cross Lapeer County in the western, northeastern, 

eastern, and southeastern portions, respectively. According 

to the February 2005 Wellogic database, approximately 23 

percent of the wells in Lapeer County are completed in the 

glacial deposits, and 72 percent in the bedrock units. There is 

insufficient information to make this distinction for 5 percent 

of the wells in the county.

The Belle River and Black River basins are part of the St. 

Clair watershed. Soils in the northwestern portion of the Belle 

River basin consist of sand, loamy sand, sandy loam, silt loam, 

limy loam, clay, muck, and peat. The southwestern portion of 

the Black River basin is located in Lapeer County. Soils in the 

Black River basin consist of poorly drained, silt, loam, and 

clay loam (Twenter, 1975).

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). The thickness of glacial 

deposits in Lapeer County ranges from 11 to 400 ft (West‐

ern Michigan University, 1981). The county is composed of 

outwash, till, and lacustrine deposits (Farrand and Bell, 1982). 

Outwash is primarily sand and gravel. Till occurs in moraine 

and till plains, and is fine to coarse grained (Farrand and Bell, 

1982). Lacustrine deposits are predominately composed of 

clay and silt. In the Belle River basin, approximately 75 ft of 

clay overlie glacial sand and gravel deposits (Twenter, 1975). 

According to the Public Water Supply database, the estimated 

transmissivity for glacial wells ranges from approximately 425 

to 10,285 ft2/day. Water from the glacial deposits may be hard 

and have a high concentration of dissolved solids in the Belle 

River basin (Twenter, 1975). Arsenic concentrations in Lapeer 

County exceed the 2006 USEPA maximum contaminant level 

of 10 μg/L in some wells (Haack and Rachol, 2000d).

The Michigan Formation, Marshall Sandstone, and Cold‐

water Shale form the bedrock surface in Lapeer County. The 

Michigan Formation consists of layers of sandstone, siltstone, 

anhydrite or gypsum, dolomite, limestone, and shale. The 

lower permeability lithologies of the Michigan Formation are 

generally considered a confining unit within the State (West‐

john and Weaver, 1998). Locally, the Michigan Formation 

can supply small quantities of water. According to the Public 

Water Supply database a well completed in the Michigan 

Formation has an estimated transmissivity of approximately 

985 ft2/day.

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone consists of one or more strati‐

graphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall 

aquifer ranges in thickness from 75 to greater than 200 ft 

within the State (Westjohn and Weaver, 1998). According to 

the Public Water Supply database, the estimated transmissivity 

for a well completed in the Marshall aquifer is approximately 

4,345 ft2/day. The Marshall aquifer yields fresh water in Lap‐

eer County (Westjohn and Weaver, 1996c). Haack and Rachol 

(2000d) found the highest arsenic concentrations in Lapeer 

County in bedrock wells tapping the Michigan Formation and 

the Marshall Sandstone.

The Coldwater Shale consists of shale, sandstone, silt‐

stone, and carbonates. This is considered to be a confining unit 

and from east to west across the State, is from 500 to 1,300 ft 

thick. More sandstone beds are present in the Coldwater Shale 

in the eastern part of the State; however, the Coldwater Shale 

does not contribute a significant amount of ground water to the 

region (Westjohn and Weaver, 1998). However, bedrock wells 

in the Black River basin obtain water from the sandstone in 

the Coldwater Shale. Underlying the Coldwater Shale is the 

Sunbury Shale, which is another predominantly shale layer 

(Twenter, 1975). Sunbury Shale is not considered an aquifer in 

the county.

Berea Sandstone underlies the Sunbury Shale. The Berea 

Sandstone consists of shale and fine‐grained, well‐sorted sand‐

40 Summary of Hydrogeologic Conditions by County for the State of Michigan
stone. In the northwestern portion of the Belle River basin, 

several wells obtain water from the Berea Sandstone (Twenter, 

1975).

Leelanau County

Leelanau County is in the northwestern portion of 

the Lower Peninsula of Michigan. A portion of Sleeping 

Bear Dunes National Lakeshore is located in the county, 

which includes North and South Manitou Island. North and 

South Fox Island are also included in Leelanau County. The 

Betsie‐Platte, Boardman‐Charlevoix, and Lake Michigan 

watersheds drain the county. According to the February 2005 

Wellogic database, approximately 94 percent of the wells in 

Leelanau County are completed in the glacial deposits, and 

1 percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 5 percent of the wells in the 

county. The majority of the bedrock wells are in the northern 

tip of the Leelanau Peninsula.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history. In the Michigan 

Basin, the glacial aquifer consists of sand and gravel that is 

part of a thick sequence of Pleistocene glacial deposits (West‐

john and others, 1994). The glacial deposits in the county 

range from 201 to 1,000 ft in thickness. However, the major‐

ity of the glacial deposits in the county are between 401 and 

800 ft thick (Western Michigan University, 1981). The glacial 

deposits in the county include outwash, lacustrine deposits, 

and till. Outwash is present in the southern portion of the 

county, and is composed of permeable sand and gravel. Till is 

coarse grained, and is present in both till plains and moraines. 

According to the Public Water Supply database, the estimated 

transmissivity for glacial till in Leelanau County is 17,856 

ft2/day.

The thickness of the glacial till on the Leelanau Peninsula 

is between 50 and greater than 150 ft, increasing southward. 

Both a portion of the Manistee Moraine and till plains with 

drumlins comprises the Leelanau Peninsula. The Manistee 

Moraine is composed of till, primarily of sand and stones that 

originated from carbonate rock. The till plains have a similar 

composition to the Manistee Moraine, except the till plains 

have a higher clay content. In both the Manistee Moraine and 

the till plains, local outwash deposits occur on the Leelanau 

Peninsula. The lacustrine deposits in the county are generally 

coarse‐grained. However some lacustrine clays are located in 

areas bordering lakes. Clay lenses also occur in the subsurface 

within the Leelanau Peninsula. The glacial aquifer is gener‐

ally unconfined in the Leelanau Peninsula. However, where 

clay‐rich till occurs, the aquifer may be semi‐confined. Along 

the Lake Leelanau and Sutton’s Bay shorelines, flowing wells 

are present, which are indicative of confined conditions. Large 

capacity wells in the area yield up to 500 gal/min (Regalbuto, 

1987).

The surficial deposits on North Fox Island include 

coarse‐grained lacustrine deposits along the shoreline, and 

dune sand in the central portion of the island. South Fox 

Island is composed of dune sand along most of the shoreline, 

coarse‐grained lacustrine deposits in the southeastern portion, 

and coarse‐grained till in the central and eastern portions of 

the island (Farrand and Bell, 1982). Glacial deposits are gener‐

ally heterogeneous in the subsurface. Some of the most promi‐

nent features in Leelanau County are the dune‐sand deposits 

which occur along the Lake Michigan shoreline.

A portion of Sleeping Bear Dunes National Lakeshore 

is located along the southwestern edge of the county and the 

glacial deposits are from 500 to 700 ft thick. In the park, the 

values for specific capacity range between less than 1 and 50 

gal/min/ft for glacial wells (Handy and Stark, 1984). Handy 

and Stark (1984) have identified areas of high specific capac‐

ity in glacial wells at and near Sleeping Bear Dunes National 

Lakeshore. These occur north and northeast of Lime Lake, 

east of Empire, west of Armstrong Lake, southeast of Glen 

Lake, and northeast of Glen Arbor (Handy and Stark, 1984, p. 

23). The ground water in Sleeping Bear Dunes National Lake‐

shore is generally of good quality, although in some areas, the 

chloride and sulfate levels are high.

The surficial deposits on North Manitou Island include 

coarse‐grained glacial till on most of the island. Areas of 

coarse‐grained lacustrine deposits are present on the northern 

and eastern parts of the island. Areas along the shoreline of 

North Manitou Island are covered in dune sand. The shoreline 

of South Manitou Island is composed of dune sand, except in 

the southern portion. Coarse‐grained till forms the southern 

and central surface of the island (Farrand and Bell, 1982). 

Ground water supplies on North Manitou Island are generally 

hard and may be hard in some areas on South Manitou Island. 

An unusual dissolved phosphorous concentration was found in 

a well on South Manitou Island (Handy and Stark, 1984).

 From southeast to northwest, the bedrock surface of 

Leelanau County is composed of the Ellsworth Shale, Antrim 

Shale, Traverse Group, and Detroit River Group which all 

underlie the glacial deposits. The Ellsworth Shale is composed 

of a gray to greenish‐gray shale. Ellsworth Shale generally 

contains some dolomite and may also be composed of sand‐

stone and siltstone layers (Matthews, 1993). The Ellsworth 

Shale is not considered an aquifer.

The Antrim Shale is composed of primarily carbona‐

ceous, black to dark‐gray shale. Near the base of the sequence, 

thin layers of gray shale and limestone may occur. The major 

constituents in the Antrim Shale consist of quartz, illite, and 

kerogen. Kaolinite, chlorite, and pyrite also compose the Ant‐

rim Shale. The Antrim Shale has been found to have bitumi‐

nous limestone concretions up to 3 ft in diameter (Matthews, 

1993). The Antrim Shale can be up to 656 ft thick, which 

occurs at the center of the Michigan Basin (Gutschick and 

Sandberg, 1991). The Antrim Shale is generally not consid‐

ered an aquifer.

 The Traverse Group underlies the Antrim Shale in the 

county. The majority of the bedrock wells in the county occur 

County Summaries  41
where the Traverse Group forms the bedrock surface. Several 

of these wells are located in the northern tip of the Leelanau 

Peninsula. The Traverse Group primarily consists of fossilif‐

erous limestone. In some areas the Traverse Group has been 

highly fractured which leads to local areas of very high perme‐

ability within that unit. In the western portion of the basin, 

porous dolomite and anhydrite may be present. In the eastern 

portion of the basin, interlayers of shale are common (Gardner, 

1974). The basal formation of the Traverse Group is the Bell 

Shale. Bell Shale has a maximum thickness of 80 ft (Cataco‐

sinos and others, 2001).

The Detroit River Group forms the Bedrock surface 

of both North and South Fox Island. In the subsurface, the 

Detroit River Group consists of the Lucas Formation, Amher‐

stburg Formation, and Sylvania Sandstone. The Lucas Forma‐

tion is primarily composed of interlayered carbonates and 

evaporites. Carbonate‐cemented, fine‐ to medium‐grained, 

sandstone lenses are scattered near the basal portion of the 

formation, sandy in northwestern. The Lucas Formation is up 

to 1,050 ft in thickness in the Michigan Basin. In some areas, 

the water from this formation is brine and may contain hydro‐

gen sulfide. The Amherstburg Formation underlies the Lucas 

Formation. The Amherstburg Formation is up to 300 ft thick 

and is composed of fossiliferous limestone that is dolomitized 

in some areas. An upper sandstone is present in the formation 

in the western portion of the basin. The Sylvania Sandstone 

underlies the Amherstburg Formation. The Sylvania Sandstone 

is composed of fine‐ to medium‐grained sandstone with quartz 

overgrowths interlayered with carbonate. Sylvania Sandstone 

has been eroded in areas of the basin (Gardner, 1974).

Lenawee County

Lenawee County is in the southeastern portion of the 

Lower Peninsula of Michigan. The Black‐Rocky, Tiffin, and 

Raisin watersheds drain the county in the central and south‐

western, north and central, and southeastern portions of the 

county, respectively. The River Raisin basin covers most of 

Lenawee County and the soils in this area consist of sand, 

sandy loam, silt loam, clay loam, limy, loam, and clay (Twen‐

ter, 1975). According to the February 2005 Wellogic database, 

approximately 89 percent of the wells in Lenawee County are 

completed in the glacial deposits, and 9 percent in the bedrock 

units. There is insufficient information to make this distinc‐

tion for 2 percent of the wells in the county. The majority of 

the wells in the central portion of the county are completed in 

glacial deposits, while bedrock wells are more common in the 

northeastern and southwestern portions of the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). In areas of the county, the glacial 

deposits are thicker than 213 ft. (Caetta, 1991). Glacial depos‐

its in Lenawee County consist of outwash, till, and lacustrine 

deposits. Glacial outwash is common in the northwestern 

portion of Lenawee County and in an area in the center of the 

county (Twenter, 1975; Farrand and Bell, 1982). Outwash 

is predominately sand and gravel deposits. According to the 

Public Water Supply database, the estimated transmissivity 

for glacial wells completed in outwash ranges from approxi‐

mately 110 to 20,735 ft2/day. Glacial deposits in the central 

portion of the county are primarily till (Twenter, 1975). Till 

deposits range from fine to coarse grained (Farrand and Bell, 

1982). The eastern and southeastern portions of the county are 

composed of glacial‐lacustrine deposits. In the areas where 

glacial‐lacustrine deposits are present, well yields are less than 

10 gal/min (Knutilla and Allen, 1975; Twenter and others, 

1975). These areas contain deposits of clay and silt, with local 

areas of sand and gravel. (Farrand and Bell, 1982). According 

to the Public Water Supply database, the estimated transmis‐

sivity for glacial wells completed in fine‐grained lacustrine 

deposits ranges from approximately 165 to 1,465 ft2/day. In 

the north‐central portion of the county, well yields range from 

10 to 20 gal/min, and from 100 to 1,000 gal/min in some parts 

(Knutilla and Allen, 1975; Twenter and others, 1975). Glacial 

wells in the southeastern portion of the county may yield min‐

eralized or saline water (Twenter, 1975; Caetta, 1991).

Bedrock underlies the glacial deposits. The bedrock 

surface is comprised of, from youngest to oldest, the Marshall 

Sandstone, Coldwater Shale, Sunbury Shale, Berea Sandstone, 

Bedford Shale, Antrim Shale, Traverse Group, Dundee Lime‐

stone, and Detroit River Group. (Knutilla and Allen, 1975; 

Twenter, 1975; Twenter and others, 1975; Milstein, 1987). 

The bedrock‐well yields range from less than 10 to 30 gal/min 

(Knutilla and Allen, 1975; Twenter and others, 1975).

The Marshall Sandstone is present in the northwest por‐

tion of the county. The Marshall Sandstone consists of one 

or more stratigraphically continuous permeable sandstones. 

The upper sandstone is a quartzarenite to sublitharenite that 

is referred to as the Napoleon Sandstone Member. A shale, 

siltstone, and/or carbonate layer separates the Napoleon Sand‐

stone Member from the underlying lower Marshall sandstone. 

The lower Marshall sandstone is comprised of two units. The 

upper unit is generally 50 to 125 ft of fine‐ to medium‐grained 

quartzarenite to sublitharenite. At the base of the Marshall 

Sandstone is a fine‐ to medium‐grained litharenite that ranges 

in thickness from 30 to 125 ft. Permeable sandstones in the 

Marshall Sandstone comprise the Marshall aquifer. The Mar‐

shall aquifer ranges in thickness from 75 to greater than 200 ft 

within the State. Transmissivity values from wells tapping the 

Marshall aquifer in nearby Jackson County are between 7,500 

and 29,000 ft2/day (Westjohn and Weaver, 1998). The Mar‐

shall aquifer yields fresh water in Lenawee County (Westjohn 

and Weaver, 1996c).

The Coldwater Shale underlies the Marshall Sandstone 

and forms the majority of the bedrock surface in Lenawee 

County. The Coldwater Shale is composed primarily of shale 

and also includes carbonate, siltstone, and sandstone. In the 

42  Summary of Hydrogeologic Conditions by County for the State of Michigan
western portion of the State, the Coldwater Shale contains 

more carbonate than siltstone or sandstone, and in the eastern 

portion of the State more sandstone beds are present in the 

Coldwater Shale (Monnett, 1948). In most of the State, the 

impermeable lithologies in the Coldwater Shale comprise the 

Coldwater confining unit (Westjohn and Weaver, 1998).

The Sunbury Shale underlies the Coldwater Shale. The 

Sunbury Shale is slightly calcareous with areas of pyrite. In 

nearby counties, the Sunbury Shale yields little, if any, water 

and is mineralized with depth. The Berea Sandstone underlies 

the Sunbury Shale. In general, the Berea Sandstone consists 

of two to three sandstones separated by shale. The upper 

unit is a fine‐grained, cemented silty and/or shaly, dolomitic 

sandstone that contains micas and pyrite in areas. The middle 

unit is more friable and consists of fine to medium sandstone 

with beds of shale and well‐cemented sandstone. The lower 

unit is a fine‐grained, cemented silty and/ or shaly, dolomitic 

sandstone that contains micas and pyrite in areas, but contains 

less pyrite and more shale (Ferris and others, 1954). Saline 

water has been recorded in wells tapping the Berea Sandstone 

in nearby Oakland County at 1,000 ft in depth (Mozola, 1954). 

The Bedford Shale underlies the Berea Sandstone. In general, 

the Bedford Shale consists of shale, sandy shale, and shaly 

limestone (Ferris and others, 1954). The Bedford Shale does 

not yield much, if any, water to wells in counties located near 

Lenawee.

The Antrim Shale underlies the Bedford Shale. In 

general, the Antrim Shale is composed of shale with concre‐

tions of pyrite and possibly anthraconite and marcasite are 

present in the Antrim Shale (Ferris and others, 1954; Nicho‐

las and others, 1996). The Traverse Group underlies Ant‐

rim Shale. Pyrite is present throughout the Traverse Group, 

which consists of beds of shale, limestone, and dolomite. The 

Dundee Limestone underlies the Traverse Group. Interbed‐

ded limestone and dolomite compose the Dundee Limestone. 

The limestone contains small vugs and the dolomite contains 

vugs and fractures. Celestite and calcite are minerals that are 

present in the vugs. Sulfur was found to occur in the fractures 

at shallow depths in areas of nearby Monroe County (Nicholas 

and others, 1996).

 The Detroit River Group underlies the Dundee Lime‐

stone. In nearby Monroe County, high concentrations of 

hydrogen sulfide were found in water from wells where the 

Dundee Limestone and the Detroit River Group formed the 

bedrock surface (Nicholas and others, 1996). Gas is found in 

the Detroit River Group in Washtenaw County. Also, in Mon‐

roe and Washtenaw County, the Detroit River Group yields 

water for domestic supplies (Fleck, 1980).

Livingston County

Livingston County is in the southeastern Lower Peninsula 

of Michigan. The Huron, Shiawassee, and the Upper Grand 

watersheds drain the county in the southern, north‐central, 

and western portions of the county, respectively. Livingston 

County soils are generally poorly drained and predominantly 

composed of clays. However, in the east and southeastern 

portion of the county, there are localized areas of sandy soils 

that allow rapid drainage (Livingston County Planning Depart‐

ment, 1993). The soils in the Huron River basin, in the south‐

ern portion of the county, are sand, sandy loam, silt loam, clay 

loam, clay, and limy loam (Twenter, 1975). According to the 

February 2005 Wellogic database, approximately 80 percent 

of the wells in Livingston County are completed in the glacial 

deposits, and 17 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 3 percent of the 

wells in the county. This is similar to the 1993 estimate from 

the Livingston County Planning Department, who found that 

approximately 81 percent of the wells in the county tap glacial 

deposits. Bedrock wells are more common on the western side 

of the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). Glacial deposits in Liv‐

ingston County are less than 100 ft thick in the west (Vanlier, 

1968) and thicken to 400 ft in the east (Twenter, 1975). Till 

and outwash are the dominant types of glacial deposits in the 

county (Vanlier, 1968; Twenter, 1975). Both moraines and till 

plains are composed of till, a compilation of clay, silt, sand, 

gravel, and boulders, and both may contain lenses of out‐

wash. The majority of the till in Livingston County is medium 

grained (Livingston County Planning Department, 1993). 

According to the Public Water Supply database, the estimated 

transmissivity for wells completed in medium‐textured till 

ranges from approximately 950 to 9,640 ft2/day. Outwash is 

composed of sand and gravel. The presence and thickness of 

outwash declines in the southwestern and western portions of 

the county (Vanlier, 1968; Twenter, 1975). According to the 

Public Water Supply database, the estimated transmissivity for 

wells completed in outwash ranges from approximately 3,350 

to 213,552 ft2/day. Water from glacial deposits is hard and 

contains some iron (Twenter, 1975).

Bedrock underlies the glacial deposits in the county. The 

crests of the Freedom Anticline and Howell Anticline run 

through Livingston County. The bedrock surface includes the 

Saginaw Formation, Bayport Limestone, Michigan Formation, 

Marshall Sandstone, Coldwater Shale, Sunbury Shale, Berea 

Sandstone, and Bedford Shale (Milstein, 1987).

In Livingston County, the Saginaw aquifer yields fresh 

water (Westjohn and Weaver, 1996c). The Saginaw Forma‐

tion contains interbeds of sandstone, siltstone, limestone, coal, 

and shale (Westjohn and Weaver, 1998). The Saginaw aquifer 

is the permeable sandstones from the Saginaw Formation. 

The Saginaw aquifer ranges in thickness from less than 100 

to 370 ft within the State (Westjohn and Weaver, 1996a). The 

Saginaw confining unit underlies the Saginaw aquifer. The 

Saginaw confining unit is approximately 50 ft thick in the 

County Summaries  43
county. It is primarily shale, with thin layers of discontinuous 

sandstone, siltstone, limestone, and coal. The permeable layers 

within the Saginaw confining unit appear to be isolated from 

the regional ground‐water‐flow system (Westjohn and Weaver, 

1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably in 

thickness from one area to another. The Bayport Limestone 

and Parma Sandstone appear to interfinger throughout the 

Michigan Basin. These units are hydraulically connected, 

and together they form the Parma‐Bayport aquifer. The 

Parma‐Bayport aquifer is approximately 100 to 150 ft thick 

within the Michigan Basin (Westjohn and Weaver, 1996a). 

Please note that due to the uncertainty of stratigraphic relation‐

ship between these units, in other reports this aquifer may be 

delineated differently. The Parma‐Bayport aquifer may yield 

saline water in Livingston County (Westjohn and Weaver, 

1996c).

The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation consists of layers of sand‐

stone, siltstone, anhydrite or gypsum, dolomite, limestone, 

and shale. The lower permeability lithologies of the Michigan 

Formation are generally considered a confining unit that 

separates the Parma‐Bayport aquifer from the underlying 

Marshall aquifer. The thickness of the Michigan confining unit 

ranges from less than 50 to 400 ft within the State (Westjohn 

and Weaver, 1998). Locally, however, the Michigan Formation 

may supply small supplies of water in the county.

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone consists of one or more strati‐

graphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall aqui‐

fer ranges in thickness from 75 to greater than 200 ft within 

the State (Westjohn and Weaver, 1998). According to the 

Public Water Supply database, the estimated transmissivity for 

Marshall aquifer ranges from approximately 2,533 to 31,680 

ft2/day. The Marshall aquifer yields both saline and fresh water 

in Livingston County (Westjohn and Weaver, 1996c)

Underlying the Marshall Sandstone is the Coldwater 

Shale. The Coldwater Shale consists of shale, sandstone, 

siltstone, and carbonates. It is generally considered a confin‐

ing unit and ranges in thickness, from east to west across the 

state, from 500 to 1,300 ft (Westjohn and Weaver, 1996b). 

More sandstone beds are present in the Coldwater Shale in the 

eastern part of the state (Monnett, 1948). In areas of Livings‐

ton County, sandstone units within the Coldwater Shale yield 

small water supplies (Twenter, 1975).

The Sunbury Shale, Berea Sandstone, and Bedford Shale 

subcrop in the southeastern corner of the county. Sunbury 

Shale underlies Coldwater Shale. Sunbury Shale is generally 

slightly calcareous shale with areas of pyrite. Sunbury Shale 

yields little if any water that is mineralized with depth. The 

Berea Sandstone underlies the Sunbury Shale. In general, the 

Berea Sandstone consists of two to three sandstones separated 

by shale. The upper unit is a fine‐grained, cemented silty and/ 

or shaly, dolomitic sandstone that contains micas and pyrite in 

areas. The middle unit is more friable and consists of fine to 

medium sandstone with beds of shale and well‐cemented sand‐

stone. The lower unit is a fine‐grained, cemented silty and/or 

shaly, dolomitic sandstone that contains micas and pyrite in 

areas, but contains less pyrite and more shale (Ferris and oth‐

ers, 1954). In areas of the State, water from the Berea Sand‐

stone may be saline or of good quality (Mozola, 1954). The 

Bedford Shale underlies the Berea Sandstone, and consists 

of shale, sandy shale, and shaly limestone (Ferris and others, 

1954). The Bedford is not considered an aquifer in the county.

Luce County

Luce County is in the eastern portion of the Upper Pen‐

insula of Michigan. The Betsy‐Chocolay, Tahquamenon, Lake 

Superior, Manistique, and Brevoort‐Millecoquins watersheds 

drain the county. According to the February 2005 Wellogic 

database, approximately 88 percent of the wells in Luce 

County are completed in the glacial deposits, and 10 percent 

in the bedrock units. There is insufficient information to make 

this distinction for 2 percent of the wells in the county. The 

glacial aquifer is the source of ground water for most of the 

wells; however, bedrock aquifers are used in areas where the 

glacial deposits are thin and/or have low permeability. Bed‐

rock wells are located in various places in the county, but the 

majority are found in two clusters in the southern portion of 

the county.

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeabil‐

ity. In Luce County, the glacial deposits are composed of till, 

outwash, lacustrine sediments, and dunes. The outwash plain, 

located just southeast of the center of the county is composed 

of sand and gravel. Three morainic systems are present. The 

Newberry Moraine is in the southern portion of the county, 

and composed primarily of sandy till, with areas of sand and 

gravel outwash. The Munising Moraine and the Crisp Point 

Moraine are located in the central and northern portion of the 

44  Summary of Hydrogeologic Conditions by County for the State of Michigan
county, respectively. These moraines are both primarily sand, 

with some lenses of coarser sand and gravel. Lacustrine depos‐

its rich in clay may separate the glacial aquifer into layers that 

are confined or semi‐confined. The glacial deposits range in 

thickness from 0 to 320 ft, and generally thin from south to 

north in the county. The average transmissivity for the glacial 

aquifer ranges between 145 to 9,820 ft2/day. This estimate is 

based on the specific capacity values from Vanlier (1959).

The bedrock underlies the glacial deposits throughout 

Luce County. The bedrock units in the county dip to the 

south, toward the center of the Michigan Basin. As a result, 

bedrock units in the county thin to the north. In the southern 

part of Luce County, the younger bedrock units are present. 

Limestone and dolomite from the Burnt Bluff Group form the 

bedrock surface in a very small area in the southeast portion of 

the county. In this area, the Burnt Bluff Group supplies water 

to wells. The Burnt Bluff Group is mainly dolomite and shale 

with areas of gypsum. The Cataract Formation underlies the 

Burnt Bluff Group and subcrops in the southern portion of 

Luce County. Layers of gypsum are present in the Cataract 

Formation, which is predominately composed of dolomite and 

shale. The estimated transmissivity, of the Cataract Formation 

is 230 ft2/day, which was calculated from specific capacity 

values (Vanlier, 1959). Water in the Cataract Formation tends 

to be of poor quality.

Below this, lies the upper portion of the Richmond 

Group. The upper portion of the Richmond Group is com‐

posed of limestone and dolomite interbedded with shale. Shaly 

and sandy dolomite is also present in the group. In Schoolcraft 

County, gypsum is found in the upper portion of the Rich‐

mond Group and this may also be true for Luce County. Water 

from the Richmond Group may be confined and the estimated 

transmissivity is 110 ft2/day. Estimated transmissivity values 

are calculated from the specific capacity values (Vanlier, 1959; 

Vanlier and Deutsch, 1958a). Water from the upper portion 

of the Richmond Group can be of good quality in some areas 

(45N 11W) while it is poor quality in other areas (45N 10W) 

of Luce County.

Below this, lies an impermeable layer of shale from the 

Richmond Group and Collingwood Shale, which combined is 

up to 200 ft thick. Underlying the Collingwood Shale is the 

Trenton and Black River Formation. The Trenton and Black 

River Formations are composed of limestone, dolomite, and 

dolomitic shale. The base of the Black River Formation is a 

shale layer. Wells in the Trenton and Black River Formations 

have supplied both fresh and saline water in nearby counties.

Underlying the Black River Formation is the Prairie 

du Chien Group and underlying Munising Formation (Van‐

lier, 1959). According to Vanlier (1959), these form a single 

confined aquifer. The Prairie du Chien Group, referred to as 

the Hermansville Formation by Vanlier (1959), is composed of 

sandstone, dolomitic sandstone, and dolomite. The Munising 

Formation underlies the Prairie du Chien Group. The Munis‐

ing Formation is composed of fine to medium‐grained sand‐

stone, and may have a conglomerate layer at the base. Water 

quality in the Prairie du Chien Group and Munising Formation 

is generally good. The Prairie du Chien Group and the Munis‐

ing Formation are sometimes used in the southern part of the 

county when the water quality of the overlying units is poor.

The Jacobsville Sandstone underlies the Munising 

Formation when the Munising Formation is present. In the 

northernmost portion of Luce County, the Jacobsville Sand‐

stone directly underlies the glacial deposits. The Jacobsville 

Sandstone is a jointed, silica‐cemented sandstone. In nearby 

counties, the permeability of the Jacobsville Sandstone 

decreases with depth (Vanlier, 1959).

Mackinac County

Mackinac County is in the southeast portion of the Upper 

Peninsula of Michigan. The Tahquamenon, Manistique, 

Brevoort‐Millecoquins, Lake Michigan, St. Marys, Carp‐Pine, 

and Lake Huron watersheds drain the county. According to the 

February 2005 Wellogic database, approximately 24 percent 

of the wells in Mackinac County are completed in the glacial 

deposits, and 68 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 8 percent of the 

wells in the county.

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

The glacial deposits in Mackinac County range in thickness 

from 0 to 300 feet. In some areas the glacial drift is discon‐

tinuous and/or thin. Glacial deposits are thickest in a bedrock 

valley that extends from St. Martin Bay, on Lake Huron, to 

Whitefish Bay, on Lake Superior. Glacial deposits consist of 

till in moraines and till plains, outwash, lacustrine deposits, 

dune sand, and beach deposits. The stratified deposits (out‐

wash, lacustrine, dune, beach and beach deposits) tend to be 

more permeable and yield more water to wells than unstrati‐

fied deposits (glacial till). In Mackinac County it is difficult to 

map the unstratified deposits because many of them have been 

eroded and covered by lacustrine deposits. Both water‐laid 

and land‐laid moraines are present in Mackinac County. They 

are composed of stratified and unstratified till, respectively. 

In both types of moraines, the degree of sorting varies. In 

general, in the east of the county, moraines are composed 

of clayey till that is a poor source of water. However, where 

lenses of sand and gravel are present in the clayey till, small 

amounts of water may be obtained. The moraines on the west‐

ern side are composed of sand and yield a moderate amount of 

water. Till plains may supply a small amount of water to local 

shallow wells because these deposits are thin and discontinu‐

ous over the surface of Mackinac County. Small to moderate 

yields of water come from outwash deposits. These deposits 

often occur near moraines, and are predominately composed of 

sand in Mackinac County. Clayey glacial lake‐plain deposits 

act as confining layers where present. Small amounts of water 

come from sandy glacial lake‐plain deposits. Small to moder‐

ate supplies of ground water may come from dune sand and 

beach deposits. Dune sand and beach deposits provide areas of 

recharge to ground water (Vanlier and Deutsch, 1958b).

County Summaries  45
Bedrock underlies the glacial deposits of Mackinac 

County. In general, the bedrock dips south in Mackinac 

County. The youngest bedrock consists of the Bois Blanc 

Formation, St. Ignace Formation, Salina Formation, and 

Mackinac Breccia. The Bois Blanc Formation and the St. 

Ignace Formation may be possible sources for ground water 

on Bois Blanc Island. Cherty dolomite and limestone make up 

the Bois Blanc Formation. The Bois Blanc Formation over‐

lies the St. Ignace Formation, which is estimated to be 200 to 

250 ft thick. The St. Ignace Formation is primarily dolomite 

and shale. The Salina Formation ranges from 500 to 600 ft 

thick and consists of shale, limestone, dolomite, gypsum, and 

some remaining layers of salt. The permeability of the Salina 

Formation varies and the water in the Salina Formation may 

be of poor quality. Ground‐water percolation led to leaching 

of the salt in the Salina Formation, which formed void space, 

and caused the Bois Blanc Formation, St. Ignace Formation, 

and Salina Formation to collapse. This created what is referred 

to as Mackinac Breccia. Mackinac Breccia is composed of the 

aggregates of the Bois Blanc Formation, St. Ignace Formation, 

and Salina Formation. The Mackinac Breccia is a poor source 

of ground water because it varies in its degree of permeability 

and is generally of poor quality.

Three quarters of the bedrock surface in Mackinac 

County is composed of limestone and dolomite of the Niagara 

Series. The Niagara Series includes Engadine Dolomite, 

Manistique Dolomite, and the Burnt Bluff Formation. Dissolu‐

tion cavities form permeable areas in the Niagara Series, and 

are an important source of water in the county. The permeable 

areas are often thin in the Niagara Series, and are separated by 

areas of lower permeability that form confining layers within 

the unit. The Niagaran Series of rocks serves as the primary 

bedrock aquifer for the county.

A layer of shale may impede the movement of water 

between the Cataract Formation and the overlying Niagara 

Series in Mackinac County (Vanlier and Deutsch, 1958b). The 

Cataract Formation is a semi‐confined to confined aquifer 

in Mackinac County and is approximately 210 ft thick. The 

Cataract Formation consists of alternating limestone, dolomite, 

and shale beds, with areas of gypsum. The Cataract Formation 

forms the bedrock surface in the northeastern and northwest‐

ern parts of Mackinac County, which allows increased move‐

ment of ground water between the Cataract Formation and 

overlying glacial deposits. The base of the Cataract Formation 

is shale (Vanlier and Deutsch, 1958a) and may confine the 

underlying upper portion of the Richmond Group in Macki‐

nac County. The upper portion of the Richmond Group is 

approximately 160 ft of limestone and dolomite. The base of 

the Richmond Group and the Collingwood Formation form 

an impermeable shale layer that is approximately 240 ft thick. 

Underlying this is the Trenton Formation and the Black River 

Formation. The Trenton and Black River Formations are com‐

posed of limestone and dolomite with sandy and shaly beds. In 

the northwest portion of the county, the Trenton Formation and 

Black River Formation produce poor quality water. The Prairie 

du Chien Group underlies the Trenton and Black River For‐

mations. Munising Sandstone underlies the Prairie du Chien 

Group. The basal shale of the Black River Formation may 

confine the Prairie du Chien Group and the Munising Sand‐

stone (Vanlier, 1959). The Prairie du Chien Group is similar 

to Munising Sandstone in composition, but contains larger 

amounts of dolomite. Munising Sandstone is composed of fine 

to medium‐grained sandstone with localized areas of dolomite. 

Combined, the Prairie du Chien Group and Munising Sand‐

stone are greater than 250 ft thick and produce good quality 

water. underlying Precambrian rocks are not a likely source of 

water in Mackinac County (Valier and Deutsch, 1958b).

Macomb County

Macomb County is in the southeastern portion of the 

Lower Peninsula of Michigan. St. Clair, Lake St. Clair, and 

Clinton watersheds drain Macomb County in the northeast‐

ern, central eastern, and the central and western portions of 

the county, respectively. In the portion of the Clinton River 

basin that is located in Macomb County, the soils are poorly 

to well‐drained sand, loamy sand, silty sand, silty loam, clay 

loam, limy loam, clay, and loam. According to the February 

2005 Wellogic database, approximately 93 percent of the wells 

in Macomb County are completed in the glacial deposits, and 

3 percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 4 percent of the wells in the 

county.

 Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

With the available information, glacial lithologies cannot be 

regionally correlated in the subsurface. This is likely due to 

the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). Glacial deposits in Macomb County consist of 

lacustrine, outwash, and till deposits (Nowlin, 1973). Both 

fine‐ to coarse‐grained lacustrine deposits are present in the 

county (Farrand and Bell, 1982). The Clinton River basin con‐

sists primarily of relatively flat lacustrine and glacial deposits 

range in thickness from 100 to 200 ft. Here, lacustrine deposits 

are composed primarily of clay and sand (Twenter, 1975; 

Nowlin, 1973). In the northwestern portion of the county, the 

surficial deposits include outwash, which is composed of sand 

and gravel (Farrand and Bell, 1982). Till plains and moraines, 

consisting of fine to coarse‐grained till, generally trend 

southwest to northeast across the county (Farrand and Bell, 

1982). The Belle River basin is part of the St. Clair watershed 

and located in the northeastern portion of the county. Here, 

the glacial deposits range in thickness from 300 ft near the 

center of Belle River basin to 150 ft. In the central portion 

of the Belle River basin, clay hardpan is approximately 75 ft 

thick and overlies sand and gravel deposits (Twenter, 1975). 

According to the Public Water Supply database, the estimated 

transmissivity for glacial wells ranges from approximately 450 

to 26,500 ft2/day. In the Clinton River basin, water from the 

46  Summary of Hydrogeologic Conditions by County for the State of Michigan
glacial wells is moderately hard and chloride and dissolved 

solid concentrations increase with depth (Twenter, 1975).

Bedrock underlies the glacial deposits. The units that 

form the bedrock surface of Macomb County, trend south‐

west to northeast, from youngest to oldest. The bedrock in the 

area consists of the Coldwater Shale, Sunbury Shale, Berea 

Sandstone, Bedford Shale, and Antrim Shale. Just east of 

Macomb County, in Oakland County, the Coldwater Shale has 

sandstone units in areas of the county that may yield sufficient 

supplies of water. In addition, the Berea Sandstone also yields 

sufficient amounts of water nearby in areas of Oakland County 

(Twenter, 1975). However, water from bedrock in the region 

tends to be mineralized, especially with increasing depth 

(Twenter and others, 1975).

The Coldwater Shale forms the bedrock surface in the 

northern portion of Macomb County (Nowlin, 1973). Coldwa‐

ter Shale consists of shale, sandstone, siltstone, and carbon‐

ates. This is generally considered to be a confining unit and 

ranges in thickness, from east to west across the State, from 

500 to 1300 ft. More sandstone beds are present in the Cold‐

water Shale in the eastern part of the State (Monnett, 1948) 

however, the Coldwater Shale does not contribute a significant 

amount of ground water to the region (Westjohn and Weaver, 

1996b). In nearby Oakland County, Coldwater Shale may 

yield freshwater where it is near the surface, but yields miner‐

alized water with depth (Ferris and others, 1954).

The Sunbury Shale, Berea Sandstone, and Bedford Shale 

form the bedrock surface southeast of the Coldwater Shale in 

Macomb County. Sunbury Shale underlies Coldwater Shale. 

Sunbury Shale is generally slightly calcareous shale with areas 

of pyrite. Sunbury Shale yields little if any water that is miner‐

alized with depth. The Berea Sandstone underlies the Sunbury 

Shale. The Berea Sandstone consists of two to three sand‐

stones separated by shale. The upper unit is a fine‐grained, 

cemented silty and/ or shaly, dolomitic sandstone that contains 

micas and pyrite in areas. The middle unit is more friable and 

consists of fine to medium sandstone with beds of shale and 

well‐cemented sandstone. The lower unit is a fine‐grained, 

cemented silty and/ or shaly, dolomitic sandstone that contains 

micas and pyrite in areas, but contains less pyrite and more 

shale (Ferris and others, 1954).

In the region where the Berea Sandstone forms the bed‐

rock surface, yields from these wells are generally adequate 

for domestic use (Twenter and others, 1975). However, saline 

water has been recorded in wells tapping Berea Sandstone 

nearby in Oakland County, near 1,000 ft in depth (Mozola, 

1954). The Bedford Shale underlies the Berea Sandstone. 

The Bedford Shale consists of shale, sandy shale, and shaly 

limestone. The Antrim Shale underlies Bedford Shale. The 

Antrim Shale is composed of shale with concretions of pyrite 

and anthraconite. The Antrim Shale yields small water sup‐

plies locally in nearby Oakland County; however, the water is 

moderately to highly mineralized (Ferris and others, 1954).

Manistee County

Manistee County is in the northwestern portion of the 

Lower Peninsula of Michigan. The western edge of the county 

borders Lake Michigan. Pere Marquette‐White, Manistee, 

Betsie‐Platte, and Lake Michigan watersheds drain the 

county. According to the February 2005 Wellogic database, 

approximately 98 percent of the wells in Manistee County are 

completed in the glacial deposits, and 0 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 2 percent of the wells in the county.

In the Michigan Basin, the glacial aquifer generally 

consists of sand and gravel that is part of a thick sequence 

of Pleistocene glacial deposits. With the available informa‐

tion, glacial lithologies cannot be regionally correlated in 

the subsurface. This is likely due to the lateral and vertical 

heterogeneity of glacial deposits that resulted from a complex 

depositional history (Westjohn and others, 1994). The glacial 

deposits range from 201 to 1,000 ft thick within Manistee 

County (Western Michigan University, 1981). The glacial 

deposits in Manistee County consist of till, lacustrine depos‐

its, and outwash. Medium‐ to coarse‐grained till is present in 

the county in moraines and till plains. The medium‐grained 

till primarily occurs in the western portion of the county. 

However, areas of coarse‐grained till occur to the east of this. 

The Port Huron Moraine occurs in the eastern portion of the 

county and is composed of coarse‐grained till. Coarse‐grained 

lacustrine deposits are present on the surface primarily in the 

central portion of the county and also in areas along the Lake 

Michigan shoreline. Outwash also is abundant in the county 

and is composed of sand and gravel. Ice‐contact outwash 

occurs in areas in the southern portion of the county (Farrand 

and Bell, 1982). The Udell Hills are located in south‐central 

Manistee County, and rise to a maximum of 300 ft above the 

surrounding level sand plains. The glacial deposits in the area 

are approximately 500 ft thick. The Udell Hills are composed 

primarily of sand. However, local gravel and boulder beds and 

clay lenses randomly occur within the hills (Kellogg, 1964). 

Sand dunes composed of fine‐ to medium‐grained sand occur 

along the Lake Michigan shoreline. According to the Public 

Water Supply database, based on aquifer tests the estimated 

transmissivity for glacial wells in the county ranges from 

approximately 990 to 37,400 ft2/day. Bedrock underlies the 

glacial deposits, but is not currently used for water supply.

Marquette County

Marquette County is in the north‐central portion of the 

Upper Peninsula of Michigan. The Dead‐Kelsey, Betsy‐Choc‐

olay, Lake Superior, Michigamme, Cedar‐Ford, Escanaba, 

and Tacoosh‐Whitefish watersheds drain the county. Mar‐

quette County relies on both glacial and bedrock aquifers 

for ground‐water supplies. According to the February 2005 

Wellogic database, approximately 64 percent of the wells in 

Marquette County are completed in the glacial deposits, and 

County Summaries  47
32 percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 4 percent of the wells in the 

county. Glacial deposits overlie the bedrock aquifers in most 

of the county. In the northern portion of the county, the thick‐

ness of the glacial deposits is extremely variable and igneous 

and metamorphic rocks are directly below the glacial deposits. 

Where glacial deposits are thick, small to moderate yields of 

water may be obtained. In areas where the glacial deposits are 

greater than 50 ft thick and underlain by sedimentary bedrock, 

water yields are high (Twenter, 1981).

Post‐glacial deposits include alluvium and swamp depos‐

its. Alluvium is primarily composed of sand and gravel, while 

swamp deposits are composed of peat, muck, silt, and clay. 

Water from these deposits may be high in iron, and generally 

yield small supplies of water (Doonan and VanAlstine, 1982).

 Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeabil‐

ity. In general, the glacial aquifer appears unconfined. How‐

ever, the aquifer is locally confined, often beneath moraines 

(Grannemann, 1984). Glacial deposits range from 0 to 500 ft 

thick and consist of moraines, outwash, and lacustrine depos‐

its. Moraines range from 0 to hundreds of ft in thickness, and 

generally consist of till. Till is composed of clay, silt, sand, 

gravel, and boulders (Doonan and VanAlstine, 1982). Outwash 

is comprised of primarily sand and gravel, and the outwash 

ranges in thickness from 0 to 300 ft thick. Sand and gravel 

outwash deposits tend to supply the most water. Lacustrine 

deposits range from 0 to 30 ft thick and are composed of strati‐

fied fine sand, silt, and clay. Water is high in iron and manga‐

nese in glacial deposits and ranges from soft to hard (Twenter, 

1981; Grannemann, 1979).

The Marquette Iron Range is located in the center of 

Marquette County, and can further be divided into four areas 

based on glacial deposits: the Sands Plain area, the West 

Branch Creek area, the Morgan Creek area, and the Carp 

Creek area. In the Sands Plain area, till consists of primar‐

ily fine sand to clay deposits, although boulder to clay‐sized 

particles are present. The hydraulic conductivity for moraines 

in Sands Plain ranges from 0.5 to 120 ft/day (Grannemann, 

1984). Grannemann defines areas in Sands Plain as transi‐

tional deposits, which are interbedded till and outwash (1984). 

Located in the Sands Plain area, the transmissivity values 

range approximately from 4,000 to 17,000 ft2/day (Wiitala 

and others, 1967). The infiltration rate is high in the Sands 

Plain area due to the abundance of sand and gravel outwash 

(Grannemann, 1979). Compared to the Sands Plain area, 

the West Branch Creek area outwash is composed of finer 

sediments, although it also contains sand and gravel. The 

estimated transmissivity from flow‐net analysis in the West 

Branch Creek area ranges approximately between 1,000 and 

4,000 ft2/day (Wiitala and others, 1967). The Morgan Creek 

area outwash is primarily composed of fine to medium sized 

grains. The transmissivity for the Morgan Creek area ranges 

approximately between 660 to 930 ft2/day (Grannemann, 

1979). The outwash in the Carp Creek area ranges from 150 

to 250 ft thick. In the Carp Creek area, a layered system is 

present in the glacial deposits. The upper unconfined aquifer is 

composed of sand and gravel, while the lower confined aquifer 

is composed of fine to coarse sand (Grannemann, 1979). 

Transmissivity values in the Carp Creek area range approxi‐

mately between 400 to 11,300 ft2/day, and confined and 

unconfined aquifers are indicated from storage coefficients 

that range from 0.00004 to 0.4 (Stuart and others, 1967).

Bedrock underlies the glacial deposits when the glacial 

deposits are present in Marquette County. The bedrock of 

Marquette County is composed of Archean igneous and meta‐

morphic rocks, Early Proterozoic metasedimentary rocks, Late 

Proterozoic sandstones, Cambrian sandstones, and Ordovician 

sandstones and carbonates. Sedimentary bedrock is near the 

ground surface along the shore of Lake Superior and in the 

southeastern portion of Marquette County. The sedimentary 

bedrock dips to the southeast. Here, the sedimentary bedrock 

provides the majority of the ground‐water supply. The fol‐

lowing is true for the sedimentary bedrock in the area. When 

all layers are present, the Black River Formation underlies 

the glacial deposits. The Black River Formation is capable 

of supplying adequate water supplies for domestic use, but 

the water may be moderately hard (Doonan and VanAlstine, 

1982). In other areas in the Upper Peninsula shale is found at 

the base of the Black River Formation, which may confine the 

underlying units (Vanlier, 1959). The Prairie du Chien‐Trem‐

pealeau unit, which underlies the Black River Formation, 

supplies larger amounts of water from its sandstone units 

than from its limestone and dolomite units, which may only 

be sufficient for domestic water supply. Munising Sandstone 

underlies the Prairie du Chien‐Trempealeau unit. The Munis‐

ing Sandstone yields moderate supplies of good quality water 

that is occasionally hard. The Munising Sandstone is friable 

and may introduce sand into some wells (Doonan and VanA‐

lstine, 1982). Jacobsville Sandstone underlies the Munising 

Sandstone. Jacobsville Sandstone provides small supplies 

of water, which may have high chloride and iron content in 

certain areas. The Jacobsville Sandstone is the main source 

of ground‐water supply along the shore of Lake Superior 

(Twenter, 1981). Precambrian metasedimentary, igneous, 

and metamorphic rocks underlie the Jacobsville Sandstone in 

Marquette County. These include the Negaunee Iron Forma‐

tion. The quality of water from bedrock aquifers varies widely. 

However, with depth the water becomes more mineralized in 

bedrock aquifers (Twenter, 1981; Grannemann, 1979).

Mason County

Mason County is in the western north‐central part of 

the Lower Peninsula of Michigan. The western portion of the 

county borders the Lake Michigan shoreline. The Pere‐Mar‐

quette‐White, Manistee, and Lake Michigan watersheds drain 

Mason County. According to the February 2005 Wellogic 

database, approximately 93 percent of the wells in Mason 

County are completed in the glacial deposits, and 0 percent in 

48  Summary of Hydrogeologic Conditions by County for the State of Michigan
the bedrock units. There is insufficient information to make 

this distinction for 7 percent of the wells in the county.

In the Michigan Basin, the glacial aquifer consists of 

sand and gravel that is part of a thick sequence of Pleisto‐

cene glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). In Mason County, the 

thickness of the glacial deposits ranges from 200 to 800 ft. 

Generally, the thickness increases to the west in the county 

(Western Michigan University, 1981). Glacial deposits include 

lacustrine deposits, till, and outwash. Lacustrine deposits, 

composed of primarily sand and gravel, are present in the 

western portion of Mason County. Till is found in till plains 

and moraines. Fine‐grained moraines and till plains are found 

interspersed in the central and western portions of the county. 

Coarse‐grained moraines and till plains are located primar‐

ily in the eastern portion of the county. Outwash is present 

in the eastern and northeastern portions of the county, and is 

composed of primarily sand and gravel. Dune sand is pres‐

ent in Mason County along the shore of Lake Michigan and 

also scattered inland in areas of the county (Farrand and Bell, 

1982). According to the Public Water Supply database, the 

estimated transmissivity for a glacial well in Mason County 

is approximately 3,310 ft2/day. Bedrock underlies the glacial 

deposits, but is not currently used for water supply.

Mecosta County

Mecosta County is in the west‐central part of the Lower 

Peninsula of Michigan. The Lower Grand, Muskegon, and 

Pine watersheds drain Mecosta County. According to the 

February 2005 Wellogic database, approximately 97 percent 

of the wells in Mecosta County are completed in the glacial 

deposits, and 0 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 3 percent of 

the wells in the county. The northeastern portion of the county 

consists of medium‐textured, adequately‐drained soils and 

sandy, well‐drained soils (Michigan Water Resources Com‐

mission, 1960).

In the Michigan Basin, the glacial aquifer consists of 

sand and gravel that is part of a thick sequence of Pleisto‐

cene glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional his‐

tory (Westjohn and others, 1994). In Mecosta County, glacial 

deposits are approximately 200 to 800 ft thick (Western Michi‐

gan University, 1981). Glacial deposits consist of primarily till 

and outwash. Till is present in till plains and moraines. The 

center of the county is covered in a coarse‐grained moraine. 

Mostly coarse‐grained till is present in the county. However, 

finer‐grained till occurs in the western and south‐central 

portions of the county (Farrand and Bell, 1982). According 

to the Public Water Supply database, the estimated transmis‐

sivity for wells completed in till in the county ranges from 

approximately 1,120 to 10,510 ft2/day. Outwash deposits also 

are present in the county. Outwash and composed of primar‐

ily sand and gravel (Farrand and Bell, 1982). According to the 

Public Water Supply database, the estimated transmissivity for 

outwash wells in the county ranges from approximately 870 to 

9,310 ft2/day. Bedrock underlies the glacial deposits, but is not 

currently used for water supplies.

Menominee County

Menominee County is in the Upper Peninsula of Michi‐

gan. Menominee, Cedar‐Ford, Escanaba, and Lake Michigan 

watersheds drain the county. According to the February 2005 

Wellogic database, approximately 8 percent of the wells in 

Menominee County are completed in the glacial deposits, and 

88 percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 4 percent of the wells in the 

county.

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

Glacial deposits in Menominee County consist of till, out‐

wash, and lacustrine deposits. Glacial deposits range from 0 

to 200 ft thick in the county. Drumlins and ground moraines 

are composed of mostly clayey till that is generally 40 ft thick, 

but can be up to 100 ft thick. In general, the drumlin and 

ground‐moraine glacial deposits do not yield large amounts 

of water. The northern moraine and drumlin deposits contain 

more sand, and yield more water than those in the southern 

portion of the county. Glacial deposits in the western portion 

of the county are thicker and are composed of more sand than 

in other areas. This area is capable of yielding large amounts 

of water. The glacial outwash supplies large amounts of water 

and is predominantly gravel. In general, the water supply from 

glacial aquifer is hard and occasionally high in iron (Vanlier, 

1963c).

The bedrock underlies the glacial deposits. The upper 

portion of the Trenton and Black River Formations form the 

bedrock surface on the east side of the county. This is some‐

times referred to as the upper‐limestone unit (Vanlier, 1963c). 

These formations are composed of primarily limestone and 

dolomite, with some shale, shaly dolomite, and shaly lime‐

stone. The abundance of shale increases in the southern por‐

tion of Menominee County. Most of the wells in the county 

tap the upper portion of Trenton and Black River Formations. 

These formations yield water containing hydrogen sulfide 

gas (sulfur water) in the southeast portion of the county. The 

water from this layer also is high in iron and is hard. This 

layer is unconfined and is subject to surface contamination. 

Underlying the upper‐limestone layer is the middle‐limestone 

and sandstone layer. This layer forms the bedrock surface in 

the west central portion of the county. The middle‐limestone 

and sandstone unit includes the St. Peter Sandstone, Prairie du 

Chien Group, and the Trempeleau Formation, and is com‐

County Summaries  49
posed of limestone, dolomite, sandstone, dolomitic sandstone, 

shaly dolomite, and sandy dolomite. The sandstone in this 

layer thins to the south of the county. The middle‐limestone 

and sandstone unit mainly supplies water to wells in this area, 

and in areas where the upper limestone yields sulfur water. In 

some areas, this aquifer supplies hard and iron rich water. The 

middle‐limestone and sandstone layer also yield sulfur water, 

locally. This aquifer may be considered confined or semi‐con‐

fined in areas by the shale that is present in the layer. The layer 

beneath is the lower‐sandstone layer. This layer is formed by 

rocks of the Franconia and Dresbach sandstones (Munising 

Formation), which consists of sandstone that is glauconitic in 

some areas. In most areas, this layer is capable of supplying 

moderate to large yields of water, but often shallower aquifers 

are used when available. The lower‐sandstone aquifer sup‐

plies water of good quality, except in the southern part of the 

county, where it yields extremely hard water. The Precambrian 

igneous, metamorphic, and sedimentary rocks underlie the 

lower sandstone unit. This layer includes Michigamme Slate, 

the Vulcan Iron Formation, Randville Dolomite, and the Quin‐

nesec Formation. This layer is less permeable with depth and 

only a few wells in the west‐central portion of the county are 

completed in the Precambrian layer (Vanlier, 1963c).

Midland County

Midland County is in the east‐central portion of the 

Lower Peninsula of Michigan. The Kawkawlin‐Pine, Tit‐

tabawassee, Pine, and Shiawassee watersheds drain the 

county. According to the February 2005 Wellogic database, 

approximately 88 percent of the wells in Midland County are 

completed in the glacial deposits, and 9 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 3 percent of the wells in the county. The western side of 

the county contains primarily glacial wells, while the eastern 

portion of the county contains both glacial and bedrock wells.

Dune sand is present on the edge of the eastside of the 

county. However, most of Midland County has poorly‐drained 

soils. The central and eastern portion of the county have sandy, 

poorly drained soils. In other areas of the county, soils of 

intermediate drainage, dry sand, and organic soils are pres‐

ent (Michigan Water Resources Commission, 1960). Areas of 

dune sand are present in the central and eastern portion of the 

county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history. In the Michigan 

Basin, the glacial aquifer consists of sand and gravel that is 

part of a thick sequence of Pleistocene glacial deposits (West‐

john and others, 1994). Glacial deposits are approximately 600 

to 1,000 ft thick in Midland County (Western Michigan Uni‐

versity, 1981). The glacial deposits are composed of primarily 

of lacustrine deposits. Both sand and gravel dominated lacus‐

trine deposits and clay and silt dominated lacustrine deposits 

are present in the county (Farrand and Bell, 1982). According 

to the Public Water Supply database, the estimated transmis‐

sivities for glacial wells from aquifer tests in Midland County 

ranges from 8,020 to 12,660 ft2/day.

Bedrock underlies the glacial deposits. The bedrock 

surface of Midland County is composed of the Jurassic “red 

beds” and the Saginaw Formation (Milstein, 1987). The Juras‐

sic “red beds” are generally 50 to 150 ft thick (Westjohn and 

others, 1994). The “red beds” occur primarily in the south‐

ern portion of the county (Milstein, 1987). The “red beds” 

consist of red clay, mudstone, siltstone, and sandstone, and 

also include gray‐green shale, gypsum, and mudstone (Shaf‐

fer, 1969). The “red beds” are considered a confining unit in 

Michigan (Westjohn and others, 1994).

Where the “red beds” are present in the county, the 

Saginaw Formation underlies the Jurassic deposits. Interbed‐

ded sandstone, siltstone, shale, coal, and limestone compose 

the Saginaw Formation. The Saginaw aquifer consists of 

hydraulically connected sandstones in the Saginaw Formation. 

Within the State, the Saginaw aquifer ranges from less than 

100 to 370 ft in thickness (Westjohn and Weaver, 1996a). The 

Saginaw aquifer yields fresh water in the eastern and northern 

parts of the county. In the central and southwestern portions 

of Midland County, the Saginaw aquifer yields saline water 

(Westjohn and Weaver, 1996c). The Saginaw confining unit 

underlies the Saginaw aquifer. The Saginaw confining unit is 

approximately less than 100 to 240 ft thick within the State, 

and is mostly shale, with thin layers of discontinuous sand‐

stone, siltstone, limestone, and coal. The permeable layers 

within the Saginaw confining unit appear to be isolated from 

the regional ground‐water‐flow system (Westjohn and Weaver, 

1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably 

in thickness from one area to another. The Bayport Lime‐

stone and Parma Sandstone appear to interfinger throughout 

the Michigan Basin (Westjohn and Weaver, 1996a). These 

units are hydraulically connected, and together they form 

the Parma‐Bayport aquifer (Westjohn and Weaver, 1996a). 

The Parma‐Bayport aquifer is approximately 100 to 150 ft 

thick within the Michigan Basin. Please note that due to the 

uncertainty of stratigraphic relationship between these units, 

in other reports this aquifer may be delineated differently. The 

Parma‐Bayport aquifer yields saline water or brine in Midland 

County (Westjohn and Weaver, 1996c).

The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation consists of layers of sand‐

stone, siltstone, anhydrite or gypsum, dolomite, limestone, 

50 Summary of Hydrogeologic Conditions by County for the State of Michigan
and shale. The lower permeability lithologies of the Michigan 

Formation are considered a confining unit that separates the 

Parma‐Bayport aquifer from the underlying Marshall aquifer. 

The thickness of the Michigan confining unit ranges from 

less than 50 to 400 ft within the State (Westjohn and Weaver, 

1998).

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone consists of one or more strati‐

graphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall aqui‐

fer ranges in thickness from 75 to greater than 200 ft within 

the State (Westjohn and Weaver, 1998). The Marshall Sand‐

stone yields brine in Midland County (Westjohn and Weaver, 

1996c).

The Coldwater Shale underlies the Marshall Sandstone. 

The Coldwater Shale consists of primarily shale with interbeds 

or lenses of sandstone, siltstone, and dolomite. The Coldwater 

Shale is relatively impermeable and is considered a confining 

unit in most of Michigan (Westjohn and Weaver, 1998).

Missaukee County

Missaukee County is in the northwestern Lower Penin‐

sula of Michigan. The Muskegon and Manistee watersheds 

drain the county. According to the February 2005 Wellogic 

database, approximately 98 percent of the wells in Missaukee 

County are completed in the glacial deposits, and 0 percent in 

the bedrock units. There is insufficient information to make 

this distinction for 2 percent of the wells in the county.

In the Michigan Basin, the glacial aquifer consists of 

sand and gravel that is part of a thick sequence of Pleisto‐

cene glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional his‐

tory (Westjohn and others, 1994). The majority of the glacial 

deposits in Missaukee County range from 401 to 600 ft thick. 

However, the thickness of the glacial deposits ranges from 201 

to 1,000 ft in the county (Western Michigan University, 1981). 

The glacial deposits in the county are composed of outwash 

and till. Outwash is composed predominantly of sand and 

gravel and is present on the surface of the county. Ice‐contact 

outwash is less abundant, and consists of poorly sorted sand 

and gravel. In the county, both coarse‐ and fine‐grained till 

occur in moraines and till plains (Farrand and Bell, 1982). 

According to the Public Water Supply database, the estimated 

transmissivity for glacial wells ranges from approximately 

1,960 to 21,270 ft2/day. Bedrock underlies the glacial deposits, 

but is not currently used for water supplies.

Monroe County

Monroe County is in the southeastern portion of the 

Lower Peninsula of Michigan. The Huron, Ottawa‐Stony, 

Raisin, Black‐Rocky, and Lake Erie watersheds cross Monroe 

County. According to the February 2005 Wellogic database, 

approximately 4 percent of the wells in Monroe County 

are completed in the glacial deposits, and 91 percent in the 

bedrock units. There is insufficient information to make this 

distinction for 5 percent of the wells in the county.

The uppermost potential aquifer is alluvium. Alluvium 

is predominantly sand and gravel and rests on glacial deposits 

that are present over almost all of the county. With the avail‐

able information, glacial lithologies cannot be regionally cor‐

related in the subsurface. This is likely due to the lateral and 

vertical heterogeneity of glacial deposits that resulted from a 

complex depositional history (Westjohn and others, 1994). The 

thickness of glacial deposits varies in Monroe County (ranging 

from 0 ft to greater than 150 ft). Glacial deposits are generally 

about 50 ft thick in most of the county. The bedrock surface 

is high trending southwest to northeast from Whiteford to 

Ash Townships, and in this area glacial deposits are generally 

only 20 ft thick. Glacial deposits are greater than 150 ft thick 

in areas where preglacial valleys were filled, such as in Milan 

and London Townships. Glacial deposits in Monroe County 

are composed of glaciolacustrine deposits, till, and glacio‐

fluvial deposits. Except where bedrock outcrops are present, 

glaciolacustrine deposits composed of sand and clay form 

the surface of the county. In areas of the county, including 

Bedford and Whiteford Townships, glaciolacustrine sand com‐

poses the surface and directly overlies the bedrock surface. 

The vertical distribution of glacial deposits varies over small 

distances. However, to generalize, till underlies the glaciola‐

custrine deposits and is predominately composed of silty clay. 

The majority of the bedrock surface is covered in till. In Milan 

Township a thick package of glaciofluvial deposits is present 

above the bedrock surface. In other areas of the county, glacio‐

fluvial deposits are present in scattered and small amounts in 

the subsurface (Nicholas and others, 1996).

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

Nicholas and others (1996) have termed the aquifer present in 

the glacial deposits, the sand aquifer. The sand aquifer is com‐

posed of discontinuous glacial sand deposits that are capable 

of yielding small amounts of water. In the northwest portion 

of the county the sand aquifer is 100 ft below the surface; 

however, it is generally at shallower depths in other areas of 

the county. In general, ground‐water flow in the sand aquifer 

follows topography. In some areas of Monroe County, perched 

ground water is present where clay deposits above the water 

table underlie the isolated sand aquifer. However, due to a 

County Summaries  51
high risk of contamination, perched aquifers are not approved 

sources of water in Monroe County. The estimated transmis‐

sivity for the sand aquifer is 360 ft2/day (Nicholas and others, 

1996).

The bedrock in Monroe County consists primarily of 

Devonian and Silurian aged carbonates and includes (in 

descending order) the Antrim Shale, Traverse Group, Dundee 

Limestone, Detroit River Group, Sylvania Sandstone, Bass 

Islands Group, and Salina Group. The bedrock dips to the 

northwest. In general, the bedrock trends southwest to north‐

east in descending order across the county. The bedrock sur‐

face is highest in the central and southwestern portion of the 

county and dips to the southeast and northwest due to erosion 

(Nicholas and others, 1996).

The Antrim Shale is the youngest bedrock present in 

Monroe County. Antrim shale subcrops in areas of Whiteford 

Township. Marcasite and pyrite are present in Antrim Shale. 

The Traverse Group comformably underlies the Antrim Shale 

and forms the bedrock surface in areas of Whiteford, Summer‐

field, Dundee, and Milan Townships. Pyrite is present through‐

out the Traverse Group, which consists of beds of shale, lime‐

stone, and dolomite. The Dundee Limestone unconformably 

underlies the Traverse Group and forms the bedrock surface in 

areas of Whiteford, Summerfield, Dundee, London, and Milan 

Townships. Interbedded limestone and dolomite compose the 

Dundee Limestone. The limestone contains small vugs and 

the dolomite contains vugs and fractures. Celestite and calcite 

are minerals that are present in the vugs. Sulfur occurs in the 

fractures at shallow depths (Nicholas and others, 1996).

The Detroit River Group is further divided into the upper 

Detroit River Group and the basal Sylvania Sandstone. The 

upper portion of the Detroit River Group unconformably 

underlies the Dundee Limestone and subcrops in areas of 

Whiteford, Summerfield, Dundee, Ida, London, Exeter, Milan, 

Raisinville, Ash, and Berlin Townships. Sinkholes from this 

formation are presenting Ida and Whiteford Townships. Inter‐

bedded limestone and dolomite compose the upper portion of 

the Detroit River Group. The limestone contains small vugs 

and the dolomite contains vugs and fractures. Celestite and 

calcite are minerals that are present in the vugs. Sulfur occurs 

in the fractures at shallow depths. Sylvania Sandstone con‐

formably underlies the upper Detroit River Group and is a cal‐

cite cemented, moderately‐ to well‐sorted, quartz sandstone. 

Pyrite, celestite, calcite, and sulfur are present in areas of the 

sandstone. Sylvania Sandstone forms the bedrock surface in 

areas of Whiteford, Summerfield, Bedford, Ida, Erie, LaSalle, 

Monroe, Raisinville, Frenchtown, Ash, Exeter, and Berlin 

Townships (Nicholas and others, 1996).

The contact between Sylvania Sandstone and the underly‐

ing Bass Islands Group is unconformable. The Bass Islands 

Group consists of beds of limestone and microcrystalline dolo‐

mite. The limestone contains small vugs and the dolomite con‐

tains vugs and fractures. Celestite and calcite are minerals that 

are present in the vugs. Sulfur occurs in the fractures at shal‐

low depths. The Bass Islands Group forms the bedrock surface 

in areas of the following Townships: Whiteford, Summerfield, 

Bedford, Ida, Erie, LaSalle, Monroe, Raisinville, Frenchtown, 

Ash, and Berlin. The Salina Group unconformably underlies 

the Bass Islands Group. In Bedford, Erie, LaSalle, and Monroe 

Townships, the southeastern part of the county, the Salina 

Group forms the bedrock surface. The Salina Group consists 

of interbeds of dolomite, limestone, and shale. The texture of 

the dolomite is microcrystalline to sucrosic. The dolomite is 

fractured and vugs exist with crystals of calcite and celestite. 

Fractures and small vugs are also present in the limestone of 

the Salina Group (Nicholas and others, 1996).

Nicholas and others (1996) termed the bedrock aquifer 

the Silurian‐Devonian aquifer. The southwestern portion of 

the county has the highest potentiometric surface. The ground 

water in the Silurian‐Devonian aquifer generally flows to the 

southeast toward Lake Erie and Ohio assuming an isotropic 

and homogenous aquifer. The highest amount of recharge to 

the Silurian‐Devonian aquifer is expected to occur in Sum‐

merfield, Ida, Whiteford, and Bedford Townships due to sand 

overlying a shallow bedrock surface. The southeast portion 

of the county may have the least amount of recharge due to a 

thicker package of less permeable clay deposits overlying the 

bedrock surface. Prior to the development, the Silurian‐Devo‐

nian aquifer was confined over most of the county. Flowing 

wells were present over most of the county (Allen, 1974). Due 

to pumping, however, the Silurian‐Devonian aquifer is now 

unconfined over most of the county. However, the Siluri‐

an‐Devonian aquifer appears to be confined in the majority of 

the county (Reeves and others, 2003). In areas of the western 

and southwestern portion of the county, the bedrock aquifer 

appears to be confined except for bedrock highs, where it is 

unconfined.

According to slug test results, the estimated transmis‐

sivity of the Silurian‐Devonian aquifer ranges between 10 

and 6,600 ft2/day, with a median transmissivity of 200 ft2/day. 

Aquifer tests have also been performed in Monroe County and 

are often better estimates of transmissivity. In Summerfield 

Township, estimated transmissivity values from an aquifer test 

in the bedrock aquifer ranged between 1,000 to 1,300 ft2/day 

with a storage coefficient ranged between 8.3 x 10‐5 and 1.2 x 

10‐4. In Bedford Township, a storage coefficient of 1.0 x 10‐4

was estimated and a transmissivity of 3,800 ft2/day from an 

aquifer test performed on the bedrock aquifer (Nicholas and 

others, 1996).

In areas in the county, high concentrations of dissolved 

solids, hydrogen sulfide, iron, and manganese were found 

in water from the Silurian‐Devonian aquifer. In areas of the 

northern and eastern portion of the county dissolved solid 

concentrations exceeded 500 mg/L. In general, water from 

the Sylvania Sandstone had higher dissolved solids concen‐

trations. High sulfate concentrations, exceeding the SMCL, 

occurred in the eastern portion of the county. Hydrogen 

sulfide concentrations greater than 0.5 mg/L occurred where 

the Dundee Limestone, and Detroit River Dolomite form the 

bedrock surface. The area trends southeast to northwest from 

Summerfield to Ash Townships. Water from wells tapping the 

Sylvania Sandstone and Bass Islands Group has the highest 

52  Summary of Hydrogeologic Conditions by County for the State of Michigan
concentrations of iron and manganese. (Nicholas and others, 

1996).

Montcalm County

Montcalm County is in the central part of the Lower Pen‐

insula of Michigan. The Maple, Lower Grand, Muskegon, and 

Pine watersheds drain the county. According to the February 

2005 Wellogic database, approximately 98 percent of the wells 

in Montcalm County are completed in the glacial deposits, and 

0 percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 2 percent of the wells in the 

county. Glacial wells supply the ground water in the county, 

because the glacial deposits are thick (Vanlier, 1968).

In the Michigan Basin, the glacial aquifer consists of sand 

and gravel that is part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). Glacial deposits range in thick‐

ness between 100 and 800 ft within Montcalm County (Van‐

lier, 1968; Western Michigan University, 1981). Although, the 

majority of the county is covered with 400 to 600 ft of glacial 

deposits (Western Michigan University, 1981). Glacial depos‐

its in the county consist of outwash and till. Outwash is com‐

posed of primarily sand and gravel. Till is present in till plains 

and moraines, and ranges from fine to coarse grained (Vanlier, 

1968; Farrand and Bell, 1982). According to the Public Water 

Supply database, the estimated transmissivity for glacial wells 

ranges from approximately 1,240 to 40,100 ft2/day. The water 

from glacial aquifer may be high in iron and hard to very hard 

(Vanlier, 1968). Bedrock underlies the glacial deposits, but is 

not currently used for water supplies in the county.

Montmorency County

Montmorency County is in the northeastern Lower Penin‐

sula of Michigan. The Lone Lake‐Ocqueoc, Boardman‐Char‐

levoix, Cheboygan, and Lake Huron watersheds drain portions 

of the county. According to the February 2005 Wellogic data‐

base, approximately 94 percent of the wells in Montmorency 

County are completed in the glacial deposits, and 1 percent in 

the bedrock units. There is insufficient information to make 

this distinction for 5 percent of the wells in the county. The 

bedrock wells are primarily in the northern portion of the 

county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). The glacial deposits in Mont‐

morency County generally range from 201 to 600 ft thick. 

However, the thickness of the glacial deposits spans from 101 

to 1,000 ft in the county (Western Michigan University, 1981). 

The glacial deposits in the county are composed of till and 

outwash. Both medium‐ and coarse‐grained till are present in 

the county. The Port Huron Moraine trends northwest to south‐

east across the county. The outwash deposits are generally 

composed of sand and gravel. Eskers occur in the northeastern 

portion of the county. Ice‐contact outwash occurs in the south‐

eastern portion of the county (Farrand and Bell, 1982).

The bedrock surface in Montmorency County is com‐

posed of the Coldwater Shale, Sunbury Shale, Berea Sand‐

stone, Bedford Shale, Antrim Shale, and Traverse Group (Mil‐

stein, 1987) which all underlies the glacial deposits. Within 

the State, the Coldwater Shale consists of primarily shale with 

interbeds or lenses of sandstone, siltstone, and dolomite. The 

Coldwater Shale is relatively impermeable and is considered 

a confining unit in most of Michigan (Westjohn and Weaver, 

1998).

The Sunbury Shale is black shale, which thins towards 

the center of the basin and is 147.6 ft thick in the eastern por‐

tion of the state (Gutschick and Sandberg, 1991). The Berea 

Sandstone underlies the Sunbury Shale. The Sunbury Shale is 

not generally considered an aquifer. The Berea Sandstone is 

fine‐ to medium‐grained sandstone. It is greater than 114.8 ft 

thick in eastern Michigan and thins to the west (Gutschick and 

Sandberg, 1991). The Berea Sandstone grades into the under‐

lying Bedford Shale and thus the upper portion of the shale is 

silty or sandy. The Bedford Shale is primarily gray shale in the 

Michigan Basin. The Bedford Shale may be greater than 213.3 

ft thick in eastern Michigan and thins toward the center of the 

Michigan Basin (Gutschick and Sandberg, 1991).

The Antrim Shale is composed of primarily carbona‐

ceous, black to dark‐gray shale. Near the base of the sequence, 

thin layers of gray shale and limestone may occur. The major 

constituents in the Antrim Shale consist of quartz, illite, 

and kerogen. Kaolinite, chlorite, and pyrite also compose 

the Antrim Shale. The Antrim Shale has been found to have 

bituminous limestone concretions up to 3 ft in diameter (Mat‐

thews, 1993). The Antrim Shale can be up to 656 ft thick, 

which occurs at the center of the Michigan Basin (Gutschick 

and Sandberg, 1991). A few bedrock wells occur where the 

Antrim Shale forms the bedrock surface. These are located in 

the northeastern portion of the county.

In Montmorency County, the Traverse Group underlies 

the Antrim Shale. The Traverse Group primarily consists of 

fossiliferous limestone. In the western portion of the basin, 

porous dolomite and anhydrite may be present. In the east‐

ern portion of the basin, interlayers of shale are common. 

(Gardner, 1974). The basal formation of the Traverse Group 

is the Bell Shale. Bell Shale has a maximum thickness of 80 

ft (Catacosinos and others, 2001). Some bedrock wells occur 

in the northeastern portion of the county, where the Traverse 

Group forms the bedrock surface.

County Summaries  53
Muskegon County

Muskegon County is in the west‐central Lower Peninsula 

of Michigan, along Lake Michigan. The Muskegon, Lower 

Grand, Pere Marquette‐White and Lake Michigan watersheds 

drain the county. Thermoelectric and industrial uses withdraw 

the most water in the county. According to the February 2005 

Wellogic database, approximately 98 percent of the wells in 

Muskegon County are completed in the glacial deposits, and 

1 percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 1 percent of the wells in the 

county. The Marshall aquifer is the most productive bedrock 

aquifer in the County (Vanlier, 1968).

In the Michigan Basin, the glacial aquifer consists of 

sand and gravel that is part of a thick sequence of Pleisto‐

cene glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). In Muskegon County, 

glacial deposits range from 100 to 800 ft thick. Most of the 

county is covered in 200 to 400 ft of glacial deposits (Western 

Michigan University, 1981). Predominantly outwash cov‐

ers the north‐central and north‐eastern portion of the county 

(Farrand and Bell, 1982). Outwash is composed of sand and 

gravel. Primarily lacustrine deposits cover the western, central, 

and southern portions of the county. The lacustrine deposits 

are composed of primarily sand and gravel (Farrand and Bell, 

1982). Till deposits occur in the northwestern and southeastern 

parts of the county. Dune deposits are scattered throughout the 

county and are especially abundant along the shore of Lake 

Michigan (Farrand and Bell, 1982). According to the Public 

Water Supply database, the estimated transmissivity for glacial 

wells ranges from approximately 990 to 6,015 ft2/day.

 Near the central‐eastern corner of Muskegon County, 

where it borders only Newaygo County, is a wastewater 

disposal system, which was the subject of a study by McDon‐

ald and Fleck (1978). This study area included portions of 

Muskegon, Newaygo, Kent, and Ottawa Counties. The western 

portion of the wastewater site is composed of 20 to 80 ft of 

well‐sorted sand that is interbedded with fine gravel and silt. 

Underneath this is primarily silt and clay. The eastern portion 

of the waste water site is primarily silt and clay‐rich till inter‐

layered with sand and gravel (McDonald and Fleck, 1978). An 

irrigation circle located in Muskegon County at the Muskegon 

County Wastewater Facility was investigated. The upper por‐

tion of the glacial deposits at the irrigation circle are composed 

of 16 to 20 ft of fine to medium‐grained sand. Approximately 

33 ft (10 m) of silty sand interlayered with silty clay, below the 

sand layer. Underneath this is a layer of silty‐clay till. Using 

a steady‐state parameter‐estimation model of the irrigation 

circle, hydraulic conductivity was estimated and ranges from 

155 to 110 ft/day (McDonald , 1980).

Bedrock underlies the glacial deposits. The bedrock 

surface in Muskegon County, from east to west, consists of the 

Bayport Limestone, Michigan Formation, Marshall Sandstone 

and Coldwater Shale. The Bayport Limestone is present only 

along the easternmost edge of the county (Milstein, 1987). The 

Bayport Limestone consists of limestone, often with interbed‐

ded sandstone and shale in Muskegon County (McDonald and 

Fleck, 1978). The Parma‐Bayport aquifer is not under Muske‐

gon County (Westjohn and Weaver, 1996a).

 The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation consists of layers of sand‐

stone, siltstone, anhydrite or gypsum, dolomite, limestone, 

and shale. The lower permeability lithologies of the Michigan 

Formation are considered a confining unit that separates the 

Parma‐Bayport aquifer from the underlying Marshall aquifer. 

The thickness of the Michigan confining unit ranges from 

less than 50 to 400 ft within the State (Westjohn and Weaver, 

1998). However, in the southeastern portion of the county, the 

Michigan Formation may yield small to moderate quantities of 

highly mineralized water (Vanlier, 1968)

The Marshall Sandstone underlies the Michigan Forma‐

tion. At the Muskegon County wastewater disposal system 

site, the Marshall Sandstone ranges in thickness from 0 to 

300 ft, from west to east (McDonald and Fleck, 1978). The 

Marshall Sandstone underlies the Michigan Formation. The 

Marshall Sandstone consists of one or more stratigraphically 

continuous permeable sandstones. The upper sandstone is a 

quartzarenite to sublitharenite that is referred to as the Napo‐

leon Sandstone Member. A shale, siltstone, and/or carbonate 

layer separates the Napoleon Sandstone Member from the 

underlying lower Marshall sandstone. The lower Marshall 

sandstone is comprised of two units. The upper unit is gener‐

ally 50 to 125 ft of fine‐ to medium‐grained quartzarenite 

to sublitharenite. At the base of the Marshall Sandstone is a 

fine‐ to medium‐grained litharenite that ranges in thickness 

from 30 to 125 ft. Permeable sandstones in the Marshall Sand‐

stone comprise the Marshall aquifer. The Marshall aquifer 

ranges in thickness from 75 to greater than 200 ft within the 

State (Westjohn and Weaver, 1998). According to the Public 

Water Supply database, the estimated transmissivity for a well 

completed in the Marshall Sandstone in Muskegon County is 

approximately 2,635 ft2/day. The Marshall aquifer is confined 

in areas of Muskegon County by the overlying impermeable 

glacial deposits or bedrock. The Marshall aquifer yields both 

fresh and saline water in Muskegon County (Vanlier, 1968; 

Westjohn and Weaver, 1996c). Household wells that yield 

water from the Marshall Sandstone are located primarily in the 

western and southern edges of the county.

The Coldwater Shale underlies the Marshall Sandstone, 

and forms the bedrock surface in the northwestern and south‐

western portions of the county (Milstein, 1987). The Coldwa‐

ter Shale consists of primarily shale with interbeds or lenses 

of sandstone, siltstone, and dolomite. The Coldwater Shale is 

relatively impermeable and is considered a confining unit in 

most of Michigan (Westjohn and Weaver, 1998).

54  Summary of Hydrogeologic Conditions by County for the State of Michigan
Newaygo County

Newaygo County is in the west‐central part of the Lower 

Peninsula of Michigan. The Lower Grand, Muskegon, and 

Pere Marquette‐White watersheds drain the county Accord‐

ing to the February 2005 Wellogic database, approximately 99 

percent of the wells in Newaygo County are completed in the 

glacial deposits, and less than 1 percent in the bedrock units. 

There is insufficient information to make this distinction for 1 

percent of the wells in the county.

In the Michigan Basin, the glacial aquifer consists of 

sand and gravel that is part of a thick sequence of Pleisto‐

cene glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). Glacial deposits range in 

thickness from 100 to 800 ft in Newaygo County. The major‐

ity of the county is covered in 200 to 400 ft of glacial deposits 

(Western Michigan University, 1981). Glacial deposits are 

composed primarily of outwash and till. Outwash is inter‐

spersed throughout the county (Farrand and Bell, 1982). 

Outwash is composed of primarily sand and gravel. Till is 

present in till plains and moraines. Mostly coarse‐grained till 

is present in the county; however, in the southern portion of 

the county, fine to medium‐grained till is present (Farrand and 

Bell, 1982). According to the Public Water Supply database, 

the estimated transmissivity for glacial wells ranges from 

approximately 6,000 to 13,370 ft2/day.

Near the central‐eastern corner of Muskegon County, 

where it borders only Newaygo County, is a wastewater 

disposal system, which was the subject of a study by McDon‐

ald and Fleck (1978). This study area included portions of 

Muskegon, Newaygo, Kent, and Ottawa Counties. The western 

portion of the wastewater site is composed of 20 to 80 ft of 

well‐sorted sand that is interbedded with fine gravel and silt. 

Underneath this is primarily silt and clay. The eastern portion 

of the waste water site is primarily silt and clay‐rich till inter‐

layered with sand and gravel (McDonald and Fleck, 1978). 

Bedrock underlies the glacial aquifer.

The bedrock surface of Newaygo County is composed 

(from east to west) of the Jurassic “red beds”, Saginaw Forma‐

tion, Bayport Limestone, and Michigan Formation (Milstein, 

1987). The “red beds” consist of red clay, mudstone, siltstone, 

and sandstone, and also include gray‐green shale, gypsum, and 

mudstone (Shaffer, 1969). The Jurassic “red beds” generally 

range between 50 to 150 ft in thickness when present, and may 

be up to 200 ft thick. The “red beds” are often poorly consoli‐

dated or unconsolidated and consist primarily of clay, mud‐

stone, siltstone, sandstone, shale, and gypsum. The “red beds” 

are relatively impermeable and are considered a confining 

unit, that impedes the vertical flow of water between glacial 

and bedrock aquifers. In the west‐central portion of the State, 

the “red beds” are usually present over the saline‐water‐bear‐

ing Pennsylvanian rocks (Westjohn and others, 1994).

Interbedded sandstone, siltstone, shale, coal, and lime‐

stone compose the Saginaw Formation, which underlies the 

Jurassic “red beds” where “red beds” are present. Sandstone 

in the Saginaw Formation is the Saginaw aquifer (Westjohn 

and Weaver, 1996a). The Saginaw aquifer ranges from less 

than 100 to 370 ft thick within the State. The Saginaw aquifer 

yields saline water in Newaygo County (Westjohn and Weaver, 

1996c). The Saginaw confining unit underlies the Saginaw 

aquifer. The Saginaw confining unit is approximately less than 

100 to 240 ft thick within the State, and is mostly shale, with 

thin layers of discontinuous sandstone, siltstone, limestone, 

and coal. The permeable layers within the Saginaw confining 

unit appear to be isolated from the regional ground‐water‐flow 

system (Westjohn and Weaver, 1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably 

in thickness from one area to another. The Bayport Lime‐

stone and Parma Sandstone appear to interfinger throughout 

the Michigan Basin (Westjohn and Weaver, 1996a). These 

units are hydraulically connected, and together they form 

the Parma‐Bayport aquifer (Westjohn and Weaver, 1996a). 

The Parma‐Bayport aquifer is approximately 100 to 150 ft 

thick within the Michigan Basin. Please note that due to the 

uncertainty of stratigraphic relationship between these units, 

in other reports this aquifer may be delineated differently. 

The Parma‐Bayport aquifer may yield saline water or brine in 

Newaygo County (Westjohn and Weaver, 1996c).

 The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation consists of layers of sand‐

stone, siltstone, anhydrite or gypsum, dolomite, limestone, 

and shale. The lower permeability lithologies of the Michigan 

Formation are considered a confining unit that separates the 

Parma‐Bayport aquifer from the underlying Marshall aquifer. 

The thickness of the Michigan confining unit ranges from 

less than 50 to 400 ft within the State (Westjohn and Weaver, 

1998).

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone consists of one or more strati‐

graphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

County Summaries  55
Sandstone comprise the Marshall aquifer. The Marshall aqui‐

fer ranges in thickness from 75 to greater than 200 ft within 

the State (Westjohn and Weaver, 1998). The Marshall aquifer 

is capable of supplying large quantities of water. The Marshall 

aquifer yields saline water or brine in Newaygo County (West‐

john and Weaver, 1996c).

The Coldwater Shale underlies the Marshall Sandstone. 

The Coldwater Shale consists of primarily shale with interbeds 

or lenses of sandstone, siltstone, and dolomite. The Coldwater 

Shale is relatively impermeable and is considered a confining 

unit in most of Michigan (Westjohn and Weaver, 1998).

Oakland County

Oakland County is in the southeastern portion of the 

Lower Peninsula of Michigan. The Shiawassee, Flint, St. Clair, 

Clinton, Detroit, and Huron watersheds are included in the 

county. According to the February 2005 Wellogic database, 

approximately 94 percent of the wells in Oakland County are 

completed in the glacial deposits, and 2 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 4 percent of the wells in the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). The northwestern portion of the Clinton River 

basin is located in northwestern Oakland County. The soils are 

poorly to well‐drained sand loamy sand, silty sand, silty loam, 

clay loam, limy loam, clay, and loam in this area of Oakland 

County (Twenter, 1975). Infiltration rates vary throughout the 

county (Aichele, 2000). Glacial deposits range in thickness 

from 20 to 350 ft, generally increasing to the northwest. The 

glacial deposits consist of moraines, till plains, lacustrine, and 

outwash. Till plains consist of poorly sorted clay, sand, gravel, 

and boulders. Sand and clay compose the lacustrine (Ferris 

and others, 1954). In the southeastern portion of the county, 

clay lacustrine deposits are common (Aichele, 2000). Outwash 

generally consists of well‐sorted sand and gravel (Ferris and 

others, 1954). The central portion of Oakland County has an 

outwash plain trending northeast to southwest (Aichele, 2000).

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and permeability. 

According to the Public Water Supply database, the estimated 

transmissivity for glacial wells in the county from approxi‐

mately 735 to greater than 43,200 ft2/day. According to Twen‐

ter and Knutilla (1972) and Ferris and others (1954), the trans‐

missivity of the glacial aquifer ranges between approximately 

1,470 and 26,700 ft2/day. The storage coefficient ranges from 

4.0 x 10‐4 to 3.4 x 10‐5 for the glacial aquifer (Ferris and oth‐

ers, 1954). The glacial aquifer is confined in certain areas and 

unconfined in others (Wisler, 1952). Water from glacial wells 

is moderately hard in the Clinton River Basin. Chloride and 

dissolved solid concentrations increase with depth in glacial 

wells (Twenter, 1975). Arsenic also occurs in glacial wells that 

are generally deeper than 40 ft, primarily in the northern por‐

tion of Oakland County. High nitrate concentrations in ground 

water from glacial aquifer are common in almost every town‐

ship in Oakland County. Chloride occurs in water from glacial 

wells, but generally has higher concentrations in bedrock wells 

(Aichele and others, 1998).

 Bedrock underlies the glacial deposits. Bedrock aquifers 

in Oakland County rarely yield potable water due to areas 

where the water has high concentrations of sulfate, iron, 

chloride, and dissolved solids (Aichele, 2000). The bedrock 

surface, in the county, consists of the Marshall Sandstone, 

Coldwater Shale, Sunbury Shale, Berea Sandstone, Bedford 

Shale, and Antrim Shale. Locally, the Coldwater Shale has 

sandstone units in areas of the county that may yield suffi‐

cient supplies of water. In addition, Berea Sandstone and the 

Marshall Sandstone yield sufficient amounts of water in areas 

of the county (Twenter, 1975). High nitrate concentrations in 

ground‐water from bedrock aquifers are common in almost 

every township in Oakland County. High chloride concentra‐

tions occur in ground water in several areas of the county 

(Aichele and others, 1998).

The Marshall Sandstone consists of one or more strati‐

graphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall aqui‐

fer ranges in thickness from 75 to greater than 200 ft within 

the State (Westjohn and Weaver, 1998). The Marshall Sand‐

stone produces adequate water supplies in Holly, Groveland, 

Brandon, and Rose Townships, all located in the northeastern 

portion of Oakland County. However, in this area, glacial wells 

are still the main source of water (Aichele, 2000). According 

to the Public Water Supply database, the estimated transmis‐

sivity for wells completed in the Marshall aquifer in Oakland 

County ranges from approximately 14,225 to 16,515 ft2/day. 

The Marshall aquifer supplies predominately fresh water in 

Oakland County. In the northeastern most corner of the county, 

the Marshall aquifer may contain saline water (Westjohn and 

Weaver, 1996c). The Marshall aquifer may yield water with 

high concentrations of arsenic in areas of the county (Aichele 

and others, 1998).

The Coldwater Shale consists of shale, sandstone, silt‐

stone, and carbonates and underlies the Marshall Sandstone. 

The Coldwater Shale is generally considered to be a confining 

unit and ranges in thickness, from 500 to 1,300 ft, from east 

to west across the State. More sandstone beds are present in 

the Coldwater Shale in the eastern part of the State (Monnett, 

1948). Also, locally in Oakland County, the Coldwater Shale 

may yield freshwater where it is near the surface, but yields 

56  Summary of Hydrogeologic Conditions by County for the State of Michigan
mineralized water with depth (Ferris and others, 1954). The 

Coldwater Shale may yield water with high concentrations of 

arsenic in areas of the county (Aichele and others, 1998).

The Sunbury Shale underlies the Coldwater Shale. The 

Sunbury Shale ranges in thickness from 0 to 50 ft and is gener‐

ally slightly calcareous shale with areas of pyrite. Sunbury 

Shale yields little, if any, water that is mineralized with depth. 

Berea Sandstone underlies Sunbury Shale. The Berea Sand‐

stone ranges in thickness from 0 to 100 ft, and consists of 

two to three sandstones separated by shale. The upper unit is 

a fine‐grained, cemented silty and/ or shaly, dolomitic sand‐

stone that contains micas and pyrite in areas. The middle unit 

is more friable and consists of fine to medium sandstone with 

beds of shale and well‐cemented sandstone. The lower unit is 

a fine‐grained, cemented, silty and/ or shaly, dolomitic sand‐

stone that contains micas and pyrite in areas, but contains less 

pyrite and more shale. The middle unit dominates the Berea 

Sandstone in the southeastern portion of Oakland County (Fer‐

ris and others, 1954). Saline water has been recorded in wells 

tapping the Berea Sandstone in Independence Township near 

1,000 ft in depth (Mozola, 1954). The Bedford Shale under‐

lies the Berea Sandstone. The Bedford Shale is 0 to 100 ft in 

thick and consists of shale, sandy shale, and shaly limestone. 

Antrim Shale underlies Bedford Shale. Antrim Shale is com‐

posed of shale with concretions of pyrite and anthraconite. The 

thickness of Antrim Shale ranges between 70 to 170 ft, and 

locally may yield small water supplies. However, the water is 

moderately to highly mineralized. The Antrim Shale forms the 

bedrock surface in the southeastern portion of Oakland County 

(Ferris and others, 1954).

Oceana County

Oceana County is in the west‐central part of the Lower 

Peninsula of Michigan. The western edge of the county 

borders the Lake Michigan shoreline. The Lake Michigan 

and Pere‐Marquette‐White watersheds drain Oceana County. 

According to the February 2005 Wellogic database, approxi‐

mately 99 percent of the wells in Oceana County are com‐

pleted in the glacial deposits, and 0 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 1 percent of the wells in the county.

In the Michigan Basin, the glacial aquifer consists of 

sand and gravel that is part of a thick sequence of Pleisto‐

cene glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). The thickness of the 

glacial deposits ranges from 200 to 800 ft in Oceana County 

(Western Michigan University, 1981). Glacial deposits 

consist of outwash and till. Outwash is interspersed through 

the central and eastern portions of the county. Outwash is 

composed of sand and gravel. Till is present in till plains and 

moraines. Coarse‐grained moraines and till plains are located 

in the central and eastern portions of the county. However, 

in the southwest and northwest portion of the county, fine to 

medium‐grained till is present. Lacustrine deposits, primar‐

ily composed of sand and gravel, are present in the northern 

portion of the county (Farrand and Bell, 1982). According to 

the Public Water Supply database, the estimated transmissivity 

for glacial wells ranges from approximately 3,530 to 10,775 

ft2/day. Bedrock underlies the glacial deposits, and is not cur‐

rently used for water supplies.

Ogemaw County

Ogemaw County is in the northeastern Lower Peninsula 

of Michigan. The Au Sable, Au Gres‐Rifle, and Tittabawas‐

see watersheds drain the county. The southwestern corner of 

Ogemaw County is drained by the Tittabawassee River. This 

area consists of well‐drained soils, adequately drained soils, 

and sands (Michigan Water Resources Commission, 1960). 

The Saginaw Lowlands cross the southern portion of the 

county. According to the February 2005 Wellogic database, 

approximately 91 percent of the wells in Ogemaw County are 

completed in the glacial deposits, and 5 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 4 percent of the wells in the county. Water from the glacial 

wells may be hard or have a high iron content. Bedrock wells 

are primarily located in the central and eastern parts of the 

county. In areas of the county, bedrock wells may provide very 

hard and/or saline water (Knutilla and others, 1971).

Glacial deposits range from 11 to 800 ft thick in the 

county (Western Michigan University, 1981). The glacial 

deposits in Ogemaw County consist of till, lacustrine, and 

outwash deposits. Till is predominant in the central and east‐

ern portions of the county. The till ranges from fine to coarse 

grained, but the majority of the till is fine grained. The lacus‐

trine deposits are primarily coarse‐grained and are dominant in 

the south‐central portion of the county. Outwash and ice‐con‐

tact outwash are abundant within in the northern portion of the 

county, and both are primarily composed of sand and gravel 

(Farrand and Bell, 1982). In the upper Rifle River basin, which 

is located in the north‐central portion of the county, the glacial 

deposits are up to 700 ft thick and are primarily composed 

of sand and gravel in the upland areas. In lowland areas, the 

glacial deposits are composed of layers of sand and gravel and 

clay. The glacial aquifer is confined in areas of the upper Rifle 

River basin, and many wells that tap this aquifer are flowing 

wells (Knutilla and others, 1971). According to the Public 

Water Supply database, the estimated transmissivity for glacial 

wells in the county ranges from approximately 270 to 1,960 

ft2/day.

The bedrock surface of Ogemaw County is composed of 

the Saginaw Formation, Bayport Limestone, Michigan Forma‐

tion, Marshall Sandstone, and Coldwater Shale. Local folding 

and erosion caused the Marshall Sandstone and Coldwater 

Shale to form the bedrock surface in areas trending northwest 

to southeast across the county.

County Summaries  57
The Saginaw Formation forms the bedrock surface in 

the southwestern portion of the county, and is composed of 

interbedded sandstone, siltstone, shale, coal, and limestone. 

The Saginaw aquifer consists of hydraulically‐connected 

sandstones in the Saginaw Formation (Westjohn and Weaver, 

1996a). Within the State, the Saginaw aquifer ranges from 

less than 100 to 370 ft thick. The Saginaw aquifer contains 

fresh water in the southwestern portion of Ogemaw County 

(Westjohn and Weaver, 1996c). The Saginaw confining unit 

underlies the Saginaw aquifer and ranges in thickness between 

50 and 240 ft within the State. It is primarily shale, with thin 

layers of discontinuous sandstone, siltstone, limestone, and 

coal. The permeable layers within the Saginaw confining unit 

appear to be isolated from the regional ground‐water‐flow 

system (Westjohn and Weaver, 1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably 

in thickness from one area to another. The Bayport Lime‐

stone and Parma Sandstone appear to interfinger throughout 

the Michigan Basin (Westjohn and Weaver, 1996a). These 

units are hydraulically connected, and together they form 

the Parma‐Bayport aquifer (Westjohn and Weaver, 1996a). 

The Parma‐Bayport aquifer is approximately 100 to 150 ft 

thick within the Michigan Basin. Please note that due to the 

uncertainty of stratigraphic relationship between these units, 

in other reports this aquifer may be delineated differently. The 

Parma‐Bayport aquifer contains fresh water in the southwest‐

ern most portion of Ogemaw County (Westjohn and Weaver, 

1996c).

Underlying the Bayport Limestone is the Michigan For‐

mation. The Michigan Formation forms the bedrock surface 

in the majority of the county. The Michigan Formation is 

composed of sandstone, shale, limestone, and occasional dolo‐

mite. Gypsum and anhydrite are also present in the formation. 

The lower permeability lithologies of the Michigan Forma‐

tion are considered to be a confining unit that separates the 

Parma‐Bayport aquifer from the underlying Marshall aquifer. 

The Michigan confining unit is approximately 50 to 400 ft 

thick within the State (Westjohn and Weaver, 1998).

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone consists of one or more strati‐

graphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall 

aquifer ranges in thickness from 75 to greater than 200 ft 

within the State (Westjohn and Weaver, 1998). The Marshall 

aquifer contains both saline and fresh water in the western and 

eastern portions of Ogemaw County, respectively (Westjohn 

and Weaver, 1996c).

The Coldwater Shale underlies the Marshall Sandstone 

and is composed of primarily shale with interbeds, or lenses, 

of sandstone, siltstone, and dolomite. The Coldwater Shale is 

relatively impermeable and is considered a confining unit in 

most of Michigan (Westjohn and Weaver, 1998).

Ontonagon County

Ontonagon County is in the western Upper Peninsula of 

Michigan. The Black‐Presque Isle, Ontonagon, Brule, Stur‐

geon, Keweenaw Peninsula, and Lake Superior watersheds 

drain the county. Doonan and Hendrickson (1969) reported 

that ground water supplies are scarce in Ontonagon County. 

According to the February 2005 Wellogic database, approxi‐

mately 36 percent of the wells in Ontonagon County are com‐

pleted in the glacial deposits, and 59 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 5 percent of the wells in the county. Most of the wells in 

the county are drilled wells that range from 50 to 300 ft in 

depth. However, dug wells, ranging from 10 to 20 ft in depth, 

also supply small amounts of water. Enlarged springs add to 

the supply of water in the county, and are generally around 4 ft 

in depth.

Aquifers in the glacial deposits consist largely of sands 

and gravels, and vary regionally in thickness and permeability. 

Glacial deposits are from 0 to 300 ft thick in the county, and 

composed of lacustrine deposits, beach sand, till, and outwash. 

Lacustrine deposits are composed of clay, silt, and sand. Most 

wells that tap lacustrine deposits, obtain water from the sandy 

deposits, however, shallow wells may obtain very small sup‐

plies of water from silt and clay. Beach sands in Ontonagon 

County yield water for the public supply near Lake Superior. 

Lacustrine deposits often supply water that has high chloride 

content, but may still be suitable for domestic use. Water 

from lacustrine deposits also has a high iron concentration 

in Ontonagon County. Till plains and moraines are primar‐

ily composed of sandy to clayey till. In the southeast portion 

of the county, moderate water supplies are obtained from 

wells completed in till that is less than 100 ft deep. Outwash 

is not abundant in Ontonagon County, but in areas where it is 

present, this deposit yields moderate amounts of water. These 

areas are southeast of Paulding and southeast of Rousseau. In 

general, sand and gravel are more abundant in the southern 

portion of the county, and therefore, the glacial deposits sup‐

ply sufficient quantities of water in this region (Doonan and 

Hendrickson, 1969). Estimated transmissivity for the glacial 

58  Summary of Hydrogeologic Conditions by County for the State of Michigan
aquifer ranges between 123 to 1,331 ft2

/day. Transmissivity 

estimations were calculated from the specific capacity data of 

Doonan and Hendrickson (1969).

In areas where glacial deposits cannot supply adequate 

amounts of water, wells are drilled to the bedrock aquifer. 

The estimated transmissivity for the bedrock aquifer ranges 

between 19 and 449 ft2/day. Transmissivity estimations were 

calculated from the specific capacity data of Doonan and 

Hendrickson (1969).

In southern Ontonagon County, Jacobsville Sandstone 

underlies the glacial deposits. Moderate supplies of water are 

obtained from Jacobsville Sandstone wells that are 100 to 300 

ft in depth. Jacobsville Sandstone occasionally yields water 

with high iron concentrations in Ontonagon County. In the 

northern portion of the county, Freda Sandstone and Nonesuch 

Shale underlie the glacial deposits. Shallower wells in this 

bedrock yield fresh water supplies. However, wells that are 

deeper than 75 ft near Lake Superior and are deeper than 150 

ft elsewhere in the county often yield saline water. The iron 

content in the Freda Sandstone and Nonesuch Shale is high in 

some areas and the water is hard.

Ancient lava flows are exposed in the Porcupine Moun‐

tains area, interbedded with conglomerate, shale, and sand‐

stone. Water from this source is often high in iron content, is 

saline, and is hard. The older volcanics, such as the Animikie 

series in the southernmost portion of the county, are not used 

to supply water, because the overlying glacial aquifer is gener‐

ally satisfactory (Doonan and Hendrickson, 1969). According 

to the Public Water Supply database, however, the estimated 

transmissivity for a bedrock well completed in basalt is 

approximately 100 ft2/day.

Osceola County

Osceola County is in the north‐central Lower Peninsula 

of Michigan. The Muskegon, Manistee, and Pine watersheds 

are included in the county. According to the February 2005 

Wellogic database, approximately 98 percent of the wells in 

Osceola County are completed in the glacial deposits, and 0 

percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 2 percent of the wells in the 

county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). Glacial deposits range in 

thickness from 400 to 1,000 ft in Osceola County. Generally, 

the thickness of the glacial deposits increases to the north‐

west (Western Michigan University, 1981). In the county, the 

glacial deposits consist of primarily till and outwash. Outwash 

is interspersed throughout the county and composed primarily 

of sand and gravel. Till is present in till plains and moraines. 

Coarse‐grained moraines and till plains are in the western 

and central portions of the county. Till of finer grain size is 

located primarily in the eastern portion of the county (Farrand 

and Bell, 1982). Glacial wells in the county, according to the 

Public Water Supply database, have estimated transmissivi‐

ties from aquifer tests that range from approximately 3,075 to 

17,425 ft2/day. Bedrock underlies the glacial deposits, but is 

not currently used for water supply.

Oscoda County

Oscoda County is in the northeastern portion of the 

Lower Peninsula of Michigan. The Thunder Bay and Au Sable 

watersheds drain the county. According to the February 2005 

Wellogic database, approximately 98 percent of the wells in 

Oscoda County are completed in the glacial deposits.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). Glacial deposits range from 101 

to 1,000 ft in thickness (Western Michigan University, 1981). 

The glacial deposits in Oscoda County consist of till, outwash, 

and lacustrine deposits. Fine‐ to coarse‐grained till is pres‐

ent in the county in moraines and till plains. The Port Huron 

Moraine trends northwest to southeast across a portion of the 

county. Outwash, composed of sand and gravel, is present 

in the county. Isolated areas of ice‐contact outwash occur in 

the northern‐central and southern portion of Oscoda County. 

Areas of fine‐grained lacustrine deposits are in the central 

portion of the county (Farrand and Bell, 1982). A glacial well 

in the county, according to the Public Water Supply database, 

has an estimated transmissivity from an aquifer test that is 

approximately 2,937 ft2/day. Bedrock underlies the glacial 

deposits, but is not currently used for water supply.

Otsego County

Otsego is in the central‐northern portion of the Lower 

Peninsula of Michigan. The Manistee, Boardman‐Charlevoix, 

Cheboygan, Black, Au Sable watersheds drain portions of 

Otsego County. According to the February 2005 Wellogic 

database, approximately 92 percent of the wells in Otsego 

County are completed in the glacial deposits, and 0 percent in 

the bedrock units. There is insufficient information to make 

this distinction for 8 percent of the wells in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). The glacial deposits in 

County Summaries  59
Otsego County range from 201 to greater than 1,000 ft thick 

(Western Michigan University, 1981). The majority of glacial 

deposits in Otsego County are composed of sand and gravel 

outwash deposits. In the southern portion of the county are 

areas of ice‐contact outwash. The northeastern portion of the 

county is also composed coarse‐grained till. Both medium‐ 

and coarse‐grained till is present in a moraine, which trends 

northwest to southeast across in the county (Farrand and Bell, 

1982). According to the Public Water Supply database, the 

estimated transmissivity for glacial wells ranges from approxi‐

mately 690 to 35,450 ft2/day. Bedrock underlies the glacial 

deposits, but is not currently used for water supplies in the 

county.

Ottawa County

Ottawa County is in the western Lower Peninsula of 

Michigan. The western portion of the county borders the Lake 

Michigan shoreline. Black‐Macatawa, Kalamazoo, Lower 

Grand, Pere Marquette‐White, and Lake Michigan water‐

sheds drain Ottawa County. According to the February 2005 

Wellogic database, approximately 62 percent of the wells in 

Ottawa County are completed in the glacial deposits, and 31 

percent in the bedrock units. There is insufficient informa‐

tion to make this distinction for 7 percent of the wells in the 

county.

Aquifers in the glacial deposits consist largely of sands 

and gravels, and vary regionally in thickness and permeability. 

With the available information, glacial lithologies cannot be 

regionally correlated in the subsurface. This is likely due to 

the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). The thickness of glacial deposits in Ottawa 

County ranges from less than 100 to greater than 400 ft thick 

(Vanlier, 1968). Lacustrine deposits, outwash, till, and dune 

sand comprise the surficial deposits in the county (Deutsch 

and others, 1958; Vanlier, 1968; Farrand and Bell, 1982). 

Lacustrine deposits are concentrated in the western and central 

portions of the county, and consist primarily of lacustrine 

sand and gravel (Farrand and Bell, 1982). In the Holland area, 

lacustrine deposits are either clay‐rich or sand‐rich deposits. 

The clay lacustrine deposits may act as a confining layer. The 

sandy lacustrine deposits and shallow outwash are considered 

one aquifer in the Holland area, because these deposits are 

interbedded and hard to distinguish from each other (Deutsch 

and others, 1958). According to the Public Water Supply data‐

base, the estimated transmissivity for glacial wells ranges from 

approximately 3,740 to 45,985 ft2/day.

The sand and gravel outwash is the most important 

water‐yielding deposit. Glacial outwash occurs primarily in 

the eastern portion of the county. However, shallow and buried 

outwash is present in the Holland area. The shallow outwash 

deposits contain some gravel, but are primarily fine to coarse 

sand. Domestic and industrial wells obtain water from the 

shallow outwash. In the Holland area, buried outwash occurs 

in two channels, the south channel and the east channel. The 

south channel occurs northeast of Holland, and continues 

westward along the shared Ottawa and Allegan County line. 

The south channel is an approximately 400 ft thick, confined 

aquifer that varies in permeability, and yields highly mineral‐

ized water. The east channel trends southeast to northwest and 

occurs along the eastern Holland city limit. The east channel is 

a confined aquifer that is up to 100 ft thick. The east channel 

supplies good quality water. The transmissivity in the east 

channel ranges from 5,347 to 13,902 ft2/day. Lenses of out‐

wash also occur interbedded within the till deposits (Deutsch 

and others, 1958).

Till occurs primarily in the southern and eastern portions 

of the county (Vanlier, 1968; Farrand and Bell, 1982). In gen‐

eral, the morainal deposits and till plains consist of till that has 

a high porosity, but low permeability. Till generally contains 

boulders, gravel, and sand in a clay and silt matrix. In some 

locales of the Holland area, more permeable sand lenses are 

present, but often these yield mineralized water. Lower perme‐

ability till is considered a confining layer in some areas. Sand 

dunes are present along the western portion of the county, 

bordering Lake Michigan (Deutsch and others, 1958; Farrand 

and Bell, 1982). Sand dunes usually lie above the water table 

and may provide areas of recharge (Deutsch and others, 1958).

Bedrock underlies the glacial deposits. The bedrock sur‐

face in Ottawa County includes, from northeast to southwest, 

the Michigan Formation, Marshall Sandstone, and Coldwater 

Shale. The Michigan Formation consists of layers of sand‐

stone, siltstone, anhydrite or gypsum, dolomite, limestone, 

and shale. The lower permeability lithologies of the Michigan 

Formation are considered a confining unit. The thickness of 

the Michigan confining unit ranges from less than 50 to 400 ft 

within the State (Westjohn and Weaver, 1998).

 The Marshall Sandstone underlies the Michigan For‐

mation. The Marshall Sandstone consists of one or more 

stratigraphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall aqui‐

fer ranges in thickness from 75 to greater than 200 ft within 

the State (Westjohn and Weaver, 1998). In the northeastern 

portion of the Holland area, the Marshall Sandstone underlies 

the glacial deposits and yields fresh water. The Marshall Sand‐

stone is mostly eroded and only the lower Marshall sandstone 

is present in the Holland area. Here, the Marshall Sandstone 

ranges in thickness from 0 to 58 ft (Deutsch and others, 1958). 

Thus, in the Holland area, the Marshall aquifer cannot supply 

large amounts of water, because it is too thin (Deutsch and 

others, 1958). However, in other areas of the county, the Mar‐

60 Summary of Hydrogeologic Conditions by County for the State of Michigan
shall aquifer is capable of supplying water. According to the 

Public Water Supply database, the estimated transmissivity for 

glacial wells ranges from approximately 615 to 1,070 ft2/day. 

In Ottawa County, the southern portion of the county may 

obtain freshwater, while the northern portion of the county 

may obtain saline water from the Marshall aquifer (Westjohn 

and Weaver, 1996c).

 The Coldwater Shale is generally considered a confin‐

ing unit within the State, and ranges in thickness from 500 to 

1,300 ft thick The Coldwater Shale consists of shale, sand‐

stone, siltstone, and carbonates. More sandstone beds are 

present in the Coldwater Shale in the eastern part of the State 

(Westjohn and Weaver, 1998). In Ottawa County, fractured 

portions of the carbonates in the Coldwater Shale may yield 

water. However, the water is highly mineralized and is not 

suitable for several uses. In the Holland area, the mineral‐

ized water from the Coldwater Shale has migrated upward in 

areas where heavy pumping of overlying aquifers takes place 

(Deutsch and others, 1958).

Presque Isle County

Presque Isle County is in the northeastern portion of the 

Lower Peninsula of Michigan. Lone Lake‐Ocqueoc, Black, 

Thunder Bay, and Lake Huron watersheds are the surface 

water drainages in the county. Lake Huron borders the 

northern and eastern portions of the county. According to the 

February 2005 Wellogic database, approximately 38 percent of 

the wells in Presque Isle County are completed in the glacial 

deposits, and 50 percent in the bedrock units. There is insuffi‐

cient information to make this distinction for 12 percent of the 

wells in the county.

 In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional his‐

tory (Westjohn and others, 1994). The glacial deposits range 

in thickness from 0 to 600 ft in Presque Isle County (Western 

Michigan University, 1981). The glacial deposits consist of 

till, outwash, and lacustrine deposits. Till plains composed of 

coarse‐textured till is abundant on the surface on areas of the 

southwestern and central portion of the county. The till plains 

contain several drumlins. Outwash, composed of sand and 

gravel, is also located in the southern portion of the county. 

Eskers are also located in the central portion of the county. 

Sand and gravel lacustrine deposits are present on the surface 

along the northern and eastern portions of the county, roughly 

following the shoreline. Sand dunes are also present along the 

shoreline. An area of peat and muck is present in the southern 

portion of the county (Farrand and Bell, 1982).

Bedrock underlies the glacial deposits. The bedrock 

surface of Presque Isle County, from south to north, is com‐

posed of the Devonian Traverse Group, Dundee Limestone, 

and Detroit River Group (Milstein, 1987). According to the 

Public Water Supply database, the estimated transmissivity 

for limestone bedrock wells ranges from approximately 610 to 

2,040 ft2/day.

The Traverse Group forms the majority of the bed‐

rock surface in southern and central portion of Presque Isle 

County. The Traverse Group primarily consists of fossiliferous 

limestone. In some areas the Traverse Group has been highly 

fractured which leads to local areas of very high permeability 

within that unit. In the western portion of the basin, porous 

dolomite and anhydrite may be present. In the eastern portion 

of the basin, interlayers of shale are common (Gardner, 1974). 

The basal formation of the Traverse Group is the Bell Shale. 

Bell Shale has a maximum thickness of 80 ft (Catacosinos 

and others, 2001). Several bedrock wells occur in the southern 

portion of the county, where the Traverse Group forms the 

bedrock surface.

The Dundee Limestone underlies the Traverse Group. 

Gardner (1974) divided the Dundee Limestone into the Roger 

City Member and underlying Reed City Member. The Rog‐

ers City Member is composed of dolomitized limestone in 

the western portion of the State and impermeable limestone 

in the eastern portion of the State. The Reed City member is 

composed of porous dolomite underlain by anhydrite. The 

anhydrite is absent in the eastern portion of the State (Gard‐

ner, 1974). Where the Dundee Limestone forms the bedrock 

surface, bedrock wells in this aquifer are generally located in 

the north‐central and eastern portions of the county.

In Presque Isle County, the Detroit River Group forms 

the bedrock surface in the northwestern portion of the county. 

In the subsurface, the Detroit River Group consists of the 

Lucas Formation, Amherstburg Formation, and Sylvania 

Sandstone. The Lucas Formation is primarily composed of 

interlayered carbonates and evaporites. Carbonate‐cemented, 

fine‐ to medium‐grained, sandstone lenses are scattered near 

the basal portion of the Lucas Formation. In the northern por‐

tion of Presque Isle County, dolomite is more abundant in the 

Lucas Formation, while in the remaining portion of the county, 

limestone is the main constituent. The Lucas Formation is 

up to 1,050 ft in thickness in the Michigan Basin. In some 

areas, the water from this formation is brine and may contain 

hydrogen sulfide. The Amherstburg Formation underlies the 

Lucas Formation. The Amherstburg Formation is up to 300 

ft thick and is composed of fossiliferous limestone that is 

dolomitized in some areas. An upper sandstone is present in 

the formation in the western portion of the Michigan Basin. 

The Sylvania Sandstone underlies the Amherstburg Formation 

and is approximately 300 ft thick. The Sylvania Sandstone is 

composed of fine‐ to medium‐grained sandstone with quartz 

overgrowths interlayered with carbonate (Gardner, 1974). The 

Sylvania Sandstone does not form part of the bedrock surface 

in Presque Isle County (Milstein, 1987). In the northwestern 

portion of the county, bedrock wells are generally located 

along the Lake Huron shoreline where the Detroit River Group 

forms the bedrock surface.

County Summaries  61
There are several karst features that occur throughout 

the county. The karst features are a result of dissolution of the 

carbonate and evaporite bedrock units and subsequent collapse 

of these units. Kimmel (1983) considered Rainy Lake, Sunken 

Lake, and the intermittent lakes near Shoepac Lake to be karst, 

sinkhole‐controlled lakes. Long, Mindack, and Trapp Lakes 

are also considered karst, solution lakes (Kimmel, 1983).

Roscommon County

Roscommon County is in the central‐northern portion of 

the Lower Peninsula of Michigan. The Muskegon, Au Sable, 

Au Gres‐Rifle, and Tittabawassee watersheds drain the county. 

According to the February 2005 Wellogic database, approxi‐

mately 96 percent of the wells in Roscommon County are 

completed in the glacial deposits, and 0 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 4 percent of the wells in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene gla‐

cial deposits. With the available information, glacial litholo‐

gies cannot be regionally correlated in the subsurface. This is 

likely due to the lateral and vertical heterogeneity of glacial 

deposits that resulted from a complex depositional history 

(Westjohn and others, 1994). The glacial deposits in Roscom‐

mon County consist primarily of outwash and ice‐contact 

outwash deposits. In the southeastern portion of the county, 

coarse‐ and fine‐grained till, and coarse‐grained lacustrine 

deposits are present (Farrand and Bell, 1982). A glacial well 

in the county, according to the Public Water Supply database, 

has an estimated transmissivity from an aquifer test that is 

approximately 13,520 ft2/day. Bedrock underlies the glacial 

deposits, but is not currently used for water supply.

Saginaw County

Saginaw County is in the east‐central Lower Peninsula 

of Michigan, in an area termed the Saginaw Lowlands. The 

Kawkawlin‐Pine, Pigeon‐Wiscoggin, Tittabawassee, Shiawas‐

see, Flint, Cass, and Saginaw watersheds drain the county. 

According to the February 2005 Wellogic database, approxi‐

mately 53 percent of the wells in Saginaw County are com‐

pleted in the glacial deposits, and 43 percent in the bedrock 

units. There is insufficient information to make this distinction 

for 4 percent of the wells in the county. Sandstones from the 

Saginaw Formation comprise the main bedrock aquifer in the 

county. In areas of Saginaw County, both bedrock and glacial 

aquifers supply saline water (Hoard and Westjohn, 2001).

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). Locally, in areas of 

Saginaw County glacial deposits are up to 600 ft thick (Handy, 

1982). The near‐surface glacial deposits in Saginaw County 

are dominated by basal‐lodgement till. The basal‐lodgment 

till is generally greater than 50 ft thick, clay‐rich, and rela‐

tively impermeable. Therefore, it acts as a confining layer to 

the underlying glaciofluvial aquifer. The glaciofluvial aquifer 

ranges in thickness from 0 to 130 ft and consists of sand and 

some gravel. The glaciofluvial aquifer is missing in areas, and 

basal lodgment till is in contact with the underlying bedrock. 

The hydraulic conductivity for the glaciofluvial aquifer based 

on aquifer tests ranges from 10 to 105 ft/day. The storage coef‐

ficient for the glaciofluvial aquifer based on aquifer tests is 6.3 

x 10‐4. The glacial aquifer yields both saline and fresh water. 

(Hoard and Westjohn, 2001).

The Saginaw Formation underlies the glacial deposits 

and consists of discontinuous interbeds of sandstone, siltstone, 

shale, limestone, and coal. The sandstone of the Saginaw 

Formation is what is referred to as the Saginaw aquifer. The 

Saginaw aquifer ranges in thickness from less than 100 to 370 

ft within the State (Westjohn and Weaver, 1996a). According 

to the Public Water Supply database, the estimated transmis‐

sivity for wells completed in the Saginaw aquifer in Saginaw 

County range from approximately 130 to 640 ft2/day. From a 

study in Lakefield, Jonesfield, Richland, and Fremont Town‐

ships the Saginaw aquifer is approximately 100 to 300 ft 

thick. The hydraulic conductivity and storage coefficient for 

the Saginaw aquifer based on an aquifer test in Lakefield 

Township is 7.7 ft/day and 3.0 x 10‐4, respectively (Hoard and 

Westjohn, 2001). The Saginaw aquifer yields fresh water in 

this area. However, in other areas of the county it yields saline 

water. The Saginaw aquifer yields fresh water only in areas 

along the western and southern edge of the county (Westjohn 

and Weaver, 1996c). The Saginaw confining unit underlies the 

Saginaw aquifer. The Saginaw confining unit is approximately 

50 to 100 ft thick in the county. It is primarily shale, with thin 

layers of discontinuous sandstone, siltstone, limestone, and 

coal. The permeable layers within the Saginaw confining unit 

appear to be isolated from the regional ground‐water‐flow 

system (Westjohn and Weaver, 1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably in 

thickness from one area to another. The Bayport Limestone 

and Parma Sandstone appear to interfinger throughout the 

Michigan Basin. These units are hydraulically connected, and 

together they form the Parma‐Bayport aquifer (Westjohn and 

Weaver, 1996a). The Parma‐Bayport aquifer is approximately 

100 to 150 ft thick within the Michigan Basin. Please note that 

due to the uncertainty of stratigraphic relationship between 

62  Summary of Hydrogeologic Conditions by County for the State of Michigan
these units, in other reports this aquifer may be delineated dif‐

ferently. The Parma‐Bayport aquifer may contain saline water 

in Saginaw County (Westjohn and Weaver, 1996c).

Underlying the Bayport Limestone is Michigan Forma‐

tion. The Michigan Formation is composed of sandstone, 

shale, limestone, and occasional dolomite. Gypsum and 

anhydrite are also present in the Michigan Formation. The low 

permeability lithologies of the Michigan Formation make up a 

confining unit that separates the Parma‐Bayport aquifer from 

the underlying Marshall aquifer. The Michigan confining unit 

is approximately 50 to 400 ft thick within the State. (Westjohn 

and Weaver, 1996b).

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone consists of one or more strati‐

graphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzar‐

enite to sublitharenite. At the base of the Marshall Sandstone 

is a fine‐ to medium‐grained litharenite that ranges in thick‐

ness from 30 to 125 ft. Permeable sandstones in the Marshall 

Sandstone comprise the Marshall aquifer. The Marshall aqui‐

fer ranges in thickness from 75 to greater than 200 ft within 

the State (Westjohn and Weaver, 1998). The Marshall aquifer 

yields both brine and saline water in Saginaw County (West‐

john and Weaver, 1996c).

The Coldwater Shale underlies the Marshall Sandstone. 

The Coldwater Shale consists of shale, sandstone, siltstone, 

and carbonates. This is considered a confining unit and ranges 

in thickness, from east to west across the State, from 500 to 

1,300 ft thick. It is the bottom unit of the Michigan Basin 

regional aquifer system. The Coldwater shale does not contrib‐

ute a significant amount ground water to the region (Westjohn 

and Weaver, 1998).

Sanilac County

Sanilac County is in the east‐central Lower Peninsula 

of Michigan. Lake Huron borders the eastern side of Sanilac 

County. Sanilac County contains the Cass (west), St. Clair 

(central), and Birch‐Willow (east) watersheds. The Black 

River Basin is part of the St. Clair watershed. According to the 

February 2005 Wellogic database, approximately 38 percent of 

the wells in Sanilac County are completed in the glacial depos‐

its, and 59 percent in the bedrock units. There is insufficient 

information to make this distinction for 3 percent of the wells 

in the county. Bedrock wells are more abundant on the western 

side of the county, while glacial wells are more abundant on 

the eastern side.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). The glacial deposits in 

Sanilac County range from 0 to 400 ft thick (Western Michi‐

gan University, 1981). Outwash, till, and lacustrine deposits 

are present in the county. Outwash, which is composed of sand 

and gravel, is present predominately in the western portion of 

the county. In the county, fine‐ to coarse‐grained till is pres‐

ent in till plains and moraines. Both fine and coarse‐grained 

lacustrine deposits also are present in the county (Farrand and 

Bell, 1982). Black River basin is a part of the St. Clair water‐

shed. Soils in the Black Glacial deposits are less than 100 ft 

thick in the northern portion, while nearly 300 ft thick in the 

central portion of the Black River basin. The northern and 

central portions of the Black River basin are located in Sanilac 

County. The glacial deposits in this area are mainly composed 

of lower permeability deposits, such as clay or a mix of clay, 

sand, and gravel (Twenter, 1975). The specific capacity values 

from the glacial deposits in the Black River basin in Sanilac 

County, according to Twenter (1975), range between 0.5 and 

2.5 gal/min/ft. According to the Public Water Supply data‐

base, the estimated transmissivity for glacial wells in Sanilac 

County ranges from approximately 3,660 to 108,680 ft2/day. 

Generally, the water from the glacial wells is hard and high 

in dissolved solid concentrations, sulfate, and iron (Twenter, 

1975). Haack and Rachol (2000a) found water from some 

glacial wells in Sanilac County to have arsenic concentrations 

that exceed the 2006 USEPA maximum contaminant level of 

10 μg/L.

The bedrock surface in the county is composed of the 

Michigan Formation, Marshall Sandstone, Coldwater Shale, 

Sunbury Shale, Berea Sandstone, Bedford Shale, and Ant‐

rim Shale. The Marshall Sandstone and Coldwater Shale are 

the bedrock aquifers in the county. The Michigan Formation 

consists of layers of sandstone, siltstone, anhydrite or gyp‐

sum, dolomite, limestone, and shale. The lower permeability 

lithologies of the Michigan Formation are considered a confin‐

ing unit. The thickness of the Michigan confining unit ranges 

from less than 50 to 400 ft within the State (Westjohn and 

Weaver, 1998).

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone is primarily composed of sand‐

stone and capable of large water yields. The Marshall Sand‐

stone in this region consists of medium‐grained sandstone with 

shale and chert, underlain by a silty shale layer, and another 

lower layer of fine to medium‐grained sandstone (Twenter, 

1975). According to the Public Water Supply database, the 

estimated transmissivity, from aquifer tests, for wells com‐

pleted in the Marshall aquifer in Sanilac County range from 

approximately 690 to 990 ft2/day.

Coldwater Shale underlies the Marshall Sandstone and 

consists of micaceous shale with siltstone, local beds of sand‐

stone, and another layer of shale with lenses of siltstone. The 

sandstone in the Coldwater Shale is capable of supplying small 

quantities of water. Specific capacity values from the bedrock 

County Summaries  63
aquifers, the Marshall Sandstone and Coldwater Shale, in the 

Black River Basin of Sanilac County range between 0.3 and 

150 gal/min/ft. Generally, the water from the bedrock is hard 

(Twenter, 1975). Water from some Marshall Sandstone wells 

in Sanilac County have arsenic concentrations that exceed the 

2006 USEPA maximum contaminant level of 10 μg/L (Haack 

and Rachol, 2000a).

 Underlying the Coldwater Shale and forming the 

bedrock surface in the southeastern portion of the county 

are bedrock layers that are generally not used as aquifers in 

Sanilac County. These units include the Sunbury Shale, Berea 

Sandstone, Bedford Shale, and Antrim Shale.

Schoolcraft County

Schoolcraft County is in the Upper Peninsula of Michi‐

gan. The Betsy‐Chocolay, Tahquamenon, Fishdam‐Sturgeon, 

Manistique, Brevoort‐Millecoquins, and Lake Michigan 

watersheds drain the county. According to the February 2005 

Wellogic database, approximately 31 percent of the wells in 

Schoolcraft County are completed in the glacial deposits, and 

65 percent in the bedrock units. There is insufficient infor‐

mation to make this distinction for 4 percent of the wells in 

the county. In general, water is more available from bedrock 

aquifers in the southern part of the county where glacial 

deposits are thinnest. Glacial deposits overlie the bedrock 

and the glacial aquifer is generally unconfined throughout the 

county. However, in areas where lenses of clay are present in 

the glacial deposits, the aquifer may be locally semi‐confined 

or confined. The uppermost portion of the bedrock aquifer is 

generally unconfined in the county.

Aquifers in the glacial deposits consist largely of sands 

and gravels, and vary regionally in thickness and permeability. 

The glacial deposits in Schoolcraft County are thickest in the 

northern part of the county and thin and discontinuous in the 

southern portion. The northern part of the county primarily 

contains sand that will yield moderate supplies of water. The 

glacial deposits range in thickness from 0 to greater than 200 

ft. The estimated transmissivity for the glacial aquifer ranges 

between 416 and 571 ft2/day (Sinclair, 1959). The glacial 

deposits include moraines, outwash, and lacustrine deposits. 

The moraine deposits are composed of glacial till, which is 

poorly sorted and varies in grain size. Generally, the till depos‐

its in areas of higher elevation in Schoolcraft County contain 

predominately poorly sorted silt and clay. Whereas in areas 

of lower elevation, till deposits have been reworked resulting 

in increased sorting and removal of fine‐grained sediments. 

This in turn causes an increase in the deposits’ permeability. 

The Cooks Moraine is located in the southwestern part of the 

county. The Cooks Moraine is very poorly sorted and contains 

a large amount of clay and silt rich till. Consequently this 

unit has a low permeability. The Newberry Moraine extends 

discontinuously across the county from east to west, and has 

been divided into the Blaney, Hiawatha, and Steuben seg‐

ments. The Blaney segment is approximately 100 ft thick. 

This segment is poorly sorted, and produces small supplies 

of water locally. Primarily sand‐rich till with areas of boul‐

der‐rich till comprises the Hiawatha and Stueben segments. 

The Hiawatha segment produces moderate yields of water and 

is approximately 200 ft thick. The same is expected for the 

Steuben segment, although no information is available. Part of 

the Munising Moraine extends across the northern portion of 

Schoolcraft County. This is primarily composed of sandy till 

and is permeable. Outwash deposits are primarily composed 

of sand and gravel. These are generally the most permeable 

glacial deposit because they are composed of reasonably well 

sorted, coarse‐grained material. Glacial outwash is located 

primarily in the northern portion of Schoolcraft County. Most 

of the lacustrine deposits in the county are sand, with some 

clay and silt that often underlie the sandy layers. In some areas 

of the county, the sandy lacustrine deposits are well sorted and 

may be a potential water source if thick enough. Lacustrine 

deposits are abundant in the central portion of the county. 

Dune deposits in the county are moderately permeable and 

consist of well‐sorted, fine‐grained sand particles. There are 

relatively few dune deposits but they can be found throughout 

the county, and may provide areas of recharge (Sinclair, 1959).

The bedrock aquifers underlie the glacial deposits, where 

glacial deposits are present in the county. In the subsurface, 

the bedrock units dip to the southeast and trend southwest to 

northeast on the bedrock surface. The oldest units form the 

bedrock surface in the northern portion of the county, and the 

youngest units in the southern portion. The estimated trans‐

missivity for the bedrock aquifers range from 36 to 4,318 

ft2/day (Sinclair, 1959; Brannen, 1997). Some transmissivity 

values were calculated using specific capacity values (Sinclair, 

1959).

When all bedrock layers are present, such as in the south‐

ern portion of the county, the uppermost bedrock is composed 

of the Engadine and Manistique Dolomites. The Engadine 

and Manistique Dolomites are composed primarily of dolo‐

mite, with some chert nodules being found in the Manistique 

Dolomite. The Engadine Dolomite does not cover a large 

area and is thin in Schoolcraft County. Where the Manistique 

Dolomite is thick, it is an important water supply, especially 

near Lake Michigan. The Burnt Bluff Formation underlies 

Manistique Dolomite and is primarily composed of dolomite 

and limestone. In Schoolcraft County, the Burnt Bluff Forma‐

tion supplies moderate supplies of water to highly populated 

areas (Sinclair, 1959). The Cataract Formation underlies the 

Burnt Bluff Formation. The Cataract Formation consists of 

dolomite with shale and gypsum. The poor water quality in the 

Cataract Formation is attributed to the dissolution of gypsum 

within this unit. The basal shale of the overlying Cataract For‐

mation, where present, may confine water within the underly‐

ing limestone and dolomite of the Richmond Group. In some 

areas, especially where the Richmond Group does not form the 

bedrock surface, it supplies water with a high mineral content. 

The lower portion of the Richmond Group and the Colling‐

wood Formation form a shale layer that ranges in thickness 

from 200 to 260 ft. This layer may confine the limestone and 

64  Summary of Hydrogeologic Conditions by County for the State of Michigan
dolomite of the underlying Trenton and Black River Forma‐

tions. In the southern portion of the county, the Trenton and 

Black River Formations supply moderate amounts of water. 

However, the water may be highly mineralized especially at 

depth in the aquifer. Below the Trenton and Black River For‐

mations is the Prairie du Chien Group. This unit is composed 

of dolomite with lenses of sandstone and sandy‐shale. The 

Munising Formation underlies the Prairie du Chien Group. 

The Munising Formation is comprised primarily of somewhat 

dolomitic sandstone with areas of shale. The Prairie du Chien 

Group and Munising Formation form the bedrock surface 

in the northern part of the county. These formations supply 

freshwater that becomes more mineralized toward the southern 

portion of the county. Underlying the Munising Formation 

is Jacobsville Sandstone. The Jacobsville Sandstone is not a 

source of water in Schoolcraft County. Below this are meta‐

morphic and igneous Precambrian rocks that are too deep and 

impermeable to supply water in the county (Sinclair, 1959).

Shiawassee County

Shiawassee County is in the south‐central Lower Pen‐

insula of Michigan. The Maple, Upper Grand, Flint, and 

Shiawassee watersheds cross the northwestern, southwest‐

ern, northeastern, and central to southeastern portions of the 

county, respectively. According to the February 2005 Wellogic 

database, approximately 36 percent of the wells in Shiawassee 

County are completed in the glacial deposits, and 59 percent 

in the bedrock units. There is insufficient information to make 

this distinction for 5 percent of the wells in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). In the Saginaw Low‐

lands, the glacial deposits are composed of mostly lacustrine 

sediments and basal lodgment till (Westjohn and Weaver, 

1998). In Shiawassee County, this area is north of Owosso, 

where a till plain has been covered with lacustrine deposits 

composed of clay and fine‐grained sand (Michigan Water 

Resources Commission, 1963). Vertical hydraulic conductivity 

of the basal lodgment till ranges between 2.83 x 10‐4and 2.83 

x 10‐5 ft/day (Westjohn and Weaver, 1998). Glacial deposits in 

the remaining portion of the county are composed of till and 

outwash (Vanlier, 1968; Michigan Water Resources Commis‐

sion, 1963). The glacial deposits range from approximately 0 

to 200 ft in thickness (Vanlier, 1968). Moraines and till plains 

are composed of medium‐ to coarse‐grained till. The outwash 

deposits consist of sand and gravel (Farrand and Bell, 1982). 

According to the Public Water Supply database, the estimated 

transmissivity of glacial wells in Shiawassee County ranges 

from approximately 220 to 200,535 ft2/day. Glacial deposits in 

the Saginaw Lowlands may yield saline water (Westjohn and 

Weaver, 1998). Haack and Rachol (2000f) found the highest 

arsenic concentrations in the county in the glacial wells.

Bedrock underlies the glacial deposits. The Grand River 

Formation, Saginaw Formation, Parma Sandstone, Bayport 

Limestone, Michigan Formation, Marshall Sandstone, and 

Coldwater Shale form the bedrock surface in the county. The 

Pennsylvanian‐aged bedrock forms the majority of the bed‐

rock surface in the county, and includes the Grand River and 

Saginaw Formations. The Grand River Formation is generally 

50 to 100 ft thick and is small in aerial extent within the State. 

It is primarily composed of coarse‐grained sandstone with 

layers of shale, carbonate, and coal (Catacosinos and others, 

2001). The Grand River Formation is difficult to differenti‐

ate from the underlying Saginaw Formation (Westjohn and 

Weaver, 1996a). The Saginaw Formation contains interbeds of 

sandstone, siltstone, limestone, coal, and shale (Westjohn and 

Weaver, 1998). The Saginaw Formation ranges in thickness 

from 100 to 400 ft, shallowing towards the southern end of the 

Shiawassee County (Michigan Water Resources Commission, 

1963). The Parma Sandstone is often considered the basal 

unit of the Saginaw Formation, although the stratigraphic 

relationship is not clear between the Saginaw Formation, 

Parma Sandstone, and underlying Mississippian‐aged Bayport 

Limestone. The Parma Sandstone is composed of medium‐ to 

coarse‐grained sandstone, and is generally less than 100 ft 

thick (Cohee and others, 1951).

The Pennsylvanian bedrock above the Parma Sandstone 

can be divided into an upper sandstone aquifer and a lower 

confining unit. The Saginaw aquifer is in the sandstones from 

the Grand River and Saginaw Formations. The Saginaw aqui‐

fer ranges in thickness from less than 100 to 370 ft within the 

State (Westjohn and Weaver, 1996a). According to the Public 

Water Supply database, in Shiawassee County the Saginaw 

aquifer has estimated transmissivities from aquifer tests that 

range from approximately 590 to 12,930 ft2/day. In most of 

Shiawassee County, the Saginaw aquifer yields fresh water; 

however, in the eastern portion of the county, the aquifer yields 

saline water (Westjohn and Weaver, 1996c). The Saginaw con‐

fining unit underlies the Saginaw aquifer. The Saginaw confin‐

ing unit is approximately 50 ft thick and is mostly shale, with 

thin layers of discontinuous sandstone, siltstone, limestone, 

and coal. The permeable layers within the Saginaw confining 

unit appear to be isolated from the regional ground‐water‐flow 

system (Westjohn and Weaver, 1996a).

Bedrock of Mississippian age underlies the Saginaw 

Formation. This includes the Bayport Limestone, Michi‐

gan Formation, Marshall Formation and Coldwater Shale. 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably in 

thickness from one area to another. The Bayport Limestone 

and Parma Sandstone appear to interfinger throughout the 

Michigan Basin. These units are hydraulically connected, and 

together they form the Parma‐Bayport aquifer (Westjohn and 

Weaver, 1996a). The Parma‐Bayport aquifer is approximately 

100 to 150 ft thick within the Michigan Basin. Please note that 

due to the uncertainty of stratigraphic relationship between 

County Summaries  65
these units, in other reports this aquifer may be delineated dif‐

ferently. The Parma‐Bayport aquifer may yield saline water in 

Shiawassee County (Westjohn and Weaver, 1996c).

The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation consists of layers of sand‐

stone, siltstone, anhydrite or gypsum, dolomite, limestone, 

and shale. The lower permeability lithologies of the Michigan 

Formation are considered a confining unit that separates the 

Parma‐Bayport aquifer from the underlying Marshall aquifer. 

The thickness of the Michigan confining unit ranges from 

less than 50 to 400 ft within the State (Westjohn and Weaver, 

1998).

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone is composed of an upper quartz‐

arenite to sublitharenite that is referred to as the Napoleon 

Sandstone Member. A shale, siltstone, and or carbonate layer 

separate the Napoleon Sandstone Member from the lower 

Marshall sandstone. The lower Marshall sandstone is com‐

prised of two units. The upper unit is generally 50 to 125 ft of 

fine‐ to medium‐grained quartzarenite to sublitharenite. At the 

base of the Marshall Sandstone is a fine‐ to medium‐grained 

litharenite. This basal sandstone ranges in thickness from 30 

to 125 ft. The permeable sandstone in the Marshall Sandstone 

is the Marshall aquifer. The Marshall aquifer is between 75 

and 200 ft thick within the State (Westjohn and Weaver, 1998). 

Shiawassee County is located somewhat in between Huron 

County and Jackson County. The Marshall aquifer in Huron 

County has transmissivity values between 7 to 50 ft2/day 

(Sweat, 1992). Transmissivity values in Jackson County are 

between 7,500 and 29,000 ft2/day. In Shiawassee County, 

however, the Marshall aquifer yields saline water (Westjohn 

and Weaver, 1996c).

The Coldwater Shale consists of shale, sandstone, 

siltstone, and carbonates. This is considered to be a confin‐

ing unit and ranges in thickness, from east to west across the 

state, from 500 to 1,300 ft. The Coldwater confining unit is 

the bottom of the Michigan Basin regional aquifer system. 

The Coldwater Shale does not contribute a significant amount 

ground water to the region (Westjohn and Weaver, 1996b).

St. Clair County

St. Clair County is in the southeastern portion of the 

Lower Peninsula of Michigan. The Birch‐Willow, Lake Huron, 

Lake St. Clair, St. Clair, and Clinton watersheds drain the 

northeastern most, northeastern, southeastern, northwestern 

and central, and southern portions of the county, respectively. 

The St. Clair watershed consists of the Black River, Belle 

River, and Pine River basins. The Black River basin is in the 

north. The Belle River basin is just south of the Black River 

basin, and between the Black River basin and the Belle River 

basin, on the eastern side of the county, is the Pine River basin. 

The Belle River basin is located along the central western 

side of St. Clair County and extends in a thin strip, trending 

southeast, to the eastern side of the county. According to the 

February 2005 Wellogic database, approximately 85 percent 

of the wells in St. Clair County are completed in the glacial 

deposits, and 13 percent in the bedrock units. There is insuf‐

ficient information to make this distinction for 2 percent of the 

wells in the county.

In the Michigan Basin, glacial aquifers consist of sand 

and gravel that are part of a thick sequence of Pleistocene 

glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). The glacial deposits 

in St. Clair County range from 101 to 400 ft thick (Western 

Michigan University, 1981). Glacial deposits generally thicken 

in the interior of St. Clair County (Twenter, 1975). Glacial 

deposits in the county include lacustrine deposits, till, and a 

small amount of sand and gravel outwash (Knutilla, 1969a, 

1969b, 1970). Along the eastern side of the county, the glacial 

deposits are composed of silty‐clay till and lacustrine deposits 

with lenses of sand and gravel (Gillespie and Dumouchelle, 

1989). Lacustrine deposits are primarily composed of silt and 

clay, however, in a few areas the lacustrine deposits are com‐

posed of sand and gravel. Till in the county ranges from fine to 

coarse grained (Farrand and Bell, 1982).

In certain areas of the county, more detailed informa‐

tion is available. In the Belle River basin, the soils are poorly 

drained loam, silt loam, clay loam, and clay. In the Pine River 

basin, in the central eastern part of the St. Clair County, these 

soils are high in lime and organic matter. There is approxi‐

mately 75 ft of clay hardpan underlying the surface and in 

areas of the Belle River basin. In the Pine River basin, clay or 

a mixture of clay, sand, and gravel is 60 to 150 ft thick. Below 

this, water supplies may be obtained from the glacial deposits. 

In general, water from the glacial deposits may be mineralized 

and hard. In the shallow glacial wells located in the Pine River 

basin, water is very hard, high in sulfate, and low in chloride. 

With depth, glacial wells contain higher concentrations of 

chloride, lower concentrations of sulfate, and are softer than 

the shallow‐glacial wells. In the Black River basin, chloride 

concentrations may be high in water from the deep glacial 

deposits (Twenter, 1975). According to the Public Water Sup‐

ply database, the estimated transmissivity for glacial wells in 

the county ranges from approximately 1,780 to 2,705 ft2/day.

In areas of the county, the glacial deposit and bedrock 

interface ranges in thickness from 5 to 20 ft. This interface 

is composed of silty sand, gravel, and fractured bedrock 

(Gillespie and Dumouchelle, 1989). The bedrock surface is 

beneath the glacial deposits or glacial‐bedrock interface. The 

bedrock surface in St. Clair County includes the Michigan 

Formation, Marshall Sandstone, Coldwater Shale, Sunbury 

Shale, Berea Sandstone, Bedford Shale, and Antrim Shale 

(Milstein, 1987; Twenter, 1975).

The Michigan Formation consists of layers of sandstone, 

siltstone, anhydrite or gypsum, dolomite, limestone, and shale. 

The lower permeability lithologies of the Michigan Formation 

are considered a confining unit. The thickness of the Michigan 

66  Summary of Hydrogeologic Conditions by County for the State of Michigan
confining unit ranges from less than 50 to 400 ft within areas 

of the State (Westjohn and Weaver, 1998).

 The Marshall Sandstone underlies the Michigan For‐

mation. Within areas of the Michigan Basin, the Marshall 

Sandstone consists of one or more stratigraphically continuous 

permeable sandstones. The upper sandstone is a quartzarenite 

to sublitharenite that is referred to as the Napoleon Sandstone 

Member. A shale, siltstone, and/or carbonate layer separates 

the Napoleon Sandstone Member from the underlying lower 

Marshall sandstone. The lower Marshall sandstone is com‐

prised of two units. The upper unit is generally 50 to 125 ft of 

fine‐ to medium‐grained quartzarenite to sublitharenite. At the 

base of the Marshall Sandstone is a fine‐ to medium‐grained 

litharenite that ranges in thickness from 30 to 125 ft. Perme‐

able sandstones in the Marshall Sandstone comprise the Mar‐

shall aquifer. The Marshall aquifer ranges in thickness from 75 

to greater than 200 ft within the State (Westjohn and Weaver, 

1998). The Marshall aquifer, in Huron County, has an esti‐

mated transmissivity that ranges from 7 to 50 ft2/day (Sweat, 

1992). The estimated transmissivity in Jackson County is from 

7,500 and 29,000 ft2/day (Westjohn and Weaver, 1998). St. 

Clair County is located somewhat between these counties. The 

Marshall aquifer yields both saline and fresh water. In general, 

salinity increases in water from the Marshall Sandstone with 

depth and inward towards the center of the State (Westjohn 

and Weaver, 1996c). In general, ground water from the Mar‐

shall Sandstone has a high concentration of dissolved solids 

and high iron content (Twenter, 1975).

The Coldwater Shale consists of shale, sandstone, silt‐

stone, and carbonates. Twenter (1975) indicated that in the 

Black River basin, in addition to the Marshall Sandstone, the 

bedrock aquifers may include sandstone units from Coldwater 

Shale. However, the Coldwater Shale is generally considered 

a confining unit. The Coldwater Shale ranges in thickness, 

from east to west across the State, from 500 to 1,300 ft thick 

(Westjohn and Weaver, 1996b). The Coldwater Shale contains 

more sandstone and siltstone in the eastern portion of the basin 

and grades into more dolomitic deposits in the western portion 

of the basin (Monnett, 1948). Water from the Coldwater Shale 

generally is low in iron content and low in dissolved solids 

(Twenter, 1975).

 The Sunbury Shale, Berea Sandstone, and Bedford Shale 

form the bedrock surface east of the Coldwater Shale in St. 

Clair County. The Sunbury Shale underlies the Coldwater 

Shale. The Sunbury Shale is generally slightly calcareous 

shale with areas of pyrite. The Sunbury Shale yields little, if 

any, water that is mineralized with depth. The Berea Sand‐

stone underlies the Sunbury Shale. The Berea Sandstone is 

approximately 125 to 175 ft below the surface and often yields 

the only potable water that can be obtained from bedrock in 

the Pine River basin. In general, the Berea Sandstone con‐

sists of two to three sandstones separated by shale. The upper 

unit is a fine‐grained, cemented silty and/or shaly, dolomitic 

sandstone that contains micas and pyrite in areas. The middle 

unit is more friable and consists of fine‐ to medium‐grained 

sandstone with beds of shale and well‐cemented sandstone. 

The lower unit is fine‐grained, cemented, silty and/or shaly, 

dolomitic sandstone that contains micas and pyrite in areas, 

but contains less pyrite and more shale (Ferris and others, 

1954). Several wells in the eastern part of the Pine River 

basin obtain water from the Berea Sandstone (Twenter, 1975). 

However, in nearby in Oakland County, saline water has been 

recorded in wells near 1,000 ft in depth that obtain water from 

the Berea Sandstone (Mozola, 1954). The Bedford Shale 

underlies the Berea Sandstone. The Bedford Shale consists 

of shale, sandy shale, and shaly limestone. The Antrim shale 

underlies the Bedford Shale. The Antrim Shale is composed of 

shale with concretions of pyrite and anthraconite. The Antrim 

Shale yields small water supplies locally in nearby Oakland 

County. However, in Oakland County, the water is moderately 

to highly mineralized (Ferris and others, 1954).

St. Joseph County

St. Joseph County is in the southwestern Lower Penin‐

sula of Michigan. The southern portion of the county borders 

Indiana. The county is in the St. Joseph watershed. According 

to the February 2005 Wellogic database, approximately 97 

percent of the wells in St. Joseph County are completed in the 

glacial deposits, and 2 percent in the bedrock units. There is 

insufficient information to make this distinction for 1 percent 

of the wells in the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). Glacial deposits range from 51 to 400 ft thick in 

the county (Western Michigan University, 1981). The glacial 

deposits in St. Joseph County are composed of outwash, and 

till. Outwash covers most of the county and is composed of 

well‐sorted sand and gravel deposits (Farrand and Bell, 1982). 

A portion of the Prairie Ronde Fan is located in the northeast‐

ern portion of Park Township in St. Joseph County. The Prairie 

Ronde Fan is a glaciofluvial fan composed of sand and gravel. 

Moraines comprised of medium to coarse till are present in the 

county (Farrand and Bell, 1982).

In the Michigan Basin, the glacial aquifer consists of 

sand and gravel that is part of a thick sequence of Pleistocene 

glacial deposits (Westjohn and others, 1994). The Prairie 

Ronde Fan overlies the regional glacial aquifer, and is laterally 

hydraulically connected to other outwash deposits. A pumping 

test was performed in a well located in Schoolcraft Township 

in Kalamazoo County that is screened in the Prairie Ronde 

Fan. This well location is just north of Park Township. The 

transmissivity of the fan was estimated to be 18,447 ft2/day at 

this well location (Kehew and others, 1996). According to the 

Public Water Supply database, the estimated transmissivity for 

outwash wells in the county ranges from approximately 360 

to 17,470 ft2/day. Several wells in rural portions of the county 

may be at risk for contamination from agricultural chemicals 

County Summaries  67
due to the high permeability of the outwash deposits (Ervin 

and Kittleson, 1988).

The majority of the wells in the county are completed 

in the glacial deposits, however, a few wells are completed in 

the underlying bedrock. The bedrock surface of the county 

consists of the Coldwater Shale and, in the southwestern por‐

tion of the county, the Ellsworth Shale (Milstein, 1987). The 

Coldwater Shale consists of shale, sandstone, siltstone, and 

carbonates. This is considered a confining unit and ranges 

in thickness, from east to west across the State, between 500 

and 1,300 ft thick. More sandstone beds are present in the 

Coldwater Shale in the eastern part of the State (Monnett, 

1948). The Ellsworth Shale is composed of shale that ranges 

in thickness from 0 to 400 ft in the State (Western Michigan 

University, 1981). The Ellsworth Shale is composed of a gray 

to greenish‐gray shale, and generally contains some dolomite. 

The Ellsworth Shale may also be composed of sandstone and 

siltstone layers (Matthews, 1993).

Tuscola County

Tuscola County is in the Saginaw Lowlands in the 

east‐central portion of the Lower Peninsula of Michigan. The 

Pigeon‐Wiscoggin, Flint, Cass, Saginaw, and Lake Huron 

watersheds cross the county. The area has a shallow water 

table and poor drainage. According to the February 2005 Wel‐

logic database, approximately 8 percent of the wells in Tuscola 

County are completed in the glacial deposits, and 89 percent 

in the bedrock units. There is insufficient information to make 

this distinction for 3 percent of the wells in the county.

The thickness of the glacial deposits ranges from 11 to 

400 ft (Western Michigan University, 1981). Glacial deposits 

include lacustrine, till, and outwash deposits. The lacustrine 

deposits usually lie on the surface and are composed of clay. 

Below these, are local deposits of sand and gravel outwash that 

when thick enough, are capable of high yields. Beneath these, 

is poorly sorted glacial till. (Mandle and Westjohn, 1987).

The bedrock surface underlies the glacial deposits. In 

Tuscola County, the bedrock surface is comprised of the 

Saginaw Formation, Bayport Limestone, Michigan Formation, 

and Coldwater Shale. The Saginaw Formation is primarily 

interbeds of shale and silty shale with some layers of siltstone, 

fine‐grained sandstone, limestone, and coal (Sweat, 1992; 

Mandle and Westjohn, 1987). The upper sandstone units are 

referred to as the Saginaw aquifer. The Saginaw aquifer ranges 

in thickness from less than 100 to 370 ft within the State 

(Westjohn and Weaver, 1996a). In Tuscola County, the Sagi‐

naw aquifer yields saline water in the western portion of the 

county, except for an area in the southwest, where the aquifer 

yields fresh water. The Saginaw confining unit underlies the 

Saginaw aquifer. The Saginaw confining unit is approximately 

50 ft thick in the county. It is primarily shale, with thin layers 

of discontinuous sandstone, siltstone, limestone, and coal. The 

permeable layers within the Saginaw confining unit appear to 

be isolated from the regional ground‐water‐flow system (West‐

john and Weaver, 1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably in 

thickness from one area to another. The Bayport Limestone 

and Parma Sandstone appear to interfinger throughout the 

Michigan Basin. These units are hydraulically connected, and 

together they form the Parma‐Bayport aquifer (Westjohn and 

Weaver, 1996a). The Parma‐Bayport aquifer is approximately 

100 to 150 ft thick within the Michigan Basin. Please note that 

due to the uncertainty of stratigraphic relationship between 

these units, in other reports this aquifer may be delineated dif‐

ferently. The Parma‐Bayport aquifer may contain saline water 

in Tuscola County (Mandle and Westjohn, 1987).

The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation is composed of sandstone, 

shale, limestone, and occasional dolomite. Gypsum and 

anhydrite are present throughout the Michigan Formation but 

are more abundant in the lower portion of the formation and in 

the western part of the county (Mandle and Westjohn, 1987; 

Sweat, 1992). Locally, wells in the Michigan Formation may 

supply water; however, the Michigan Formation is generally 

considered to be a confining unit. Often water from the forma‐

tion is saline. Haack and Rachol (2000g) found the highest 

arsenic concentrations in Tuscola County to occur in Elkhand 

Township in wells completed in the Saginaw and Michigan 

Formations.

The Marshall Sandstone underlies the Michigan Forma‐

tion. In Tuscola County, the upper portion of the Marshall 

Sandstone is a micaceous, cemented sandstone. The lower 

portion of the Marshall Sandstone contains sandstones that 

contain hematite and layers of shale‐rich sandstone that transi‐

tion into the Coldwater Shale (Mandle and Westjohn, 1987). 

The Marshall aquifer is composed of the sandstones within the 

Marshall Sandstone that are permeable and continuous (West‐

john and Weaver, 1996b). Water from the Marshall Sandstone 

is saline in the majority of Tuscola County (Westjohn and 

Weaver, 1996c).

The Coldwater Shale underlies the Marshall Sandstone. 

The Coldwater Shale is considered to be a confining unit 

within the State, and consists of mostly shale. Within the State, 

areas of siltstone, sandstone, dolomite, and limestone are also 

included in the Coldwater confining unit. In general, the Cold‐

water confining unit does not yield water supplies (Westjohn 

and Weaver, 1996b).

68  Summary of Hydrogeologic Conditions by County for the State of Michigan
Van Buren County

Van Buren County is along the shore of Lake Michi‐

gan in the southwestern portion of the Lower Peninsula. In 

addition to Lake Michigan, the county is drained by the St. 

Joseph, Black‐Macatawa, and Kalamazoo watersheds. The 

glacial aquifer is the primary source of ground water. Accord‐

ing to the February 2005 Wellogic database, approximately 

98 percent of the wells in Van Buren County are completed 

in the glacial deposits, and less than 1 percent in the bedrock 

units. There is insufficient information to make this distinc‐

tion for 2 percent of the wells in the county. In general, the 

glacial aquifer is unconfined except where clay‐rich, glaciola‐

custrine deposits act as a confining layer. The thickness of the 

glacial deposits varies within the county. Glacial deposits do 

not always correlate beneath the surface (Giroux and others, 

1964). Within the State, this is likely due to the lateral and 

vertical heterogeneity of glacial deposits that resulted from 

a complex depositional history (Westjohn and others, 1994). 

Post‐glacial deposits in Van Buren County consist of eolian 

deposits, lacustrine deposits, and alluvium. Eolian depos‐

its consist of primarily dune sand along the Lake Michigan 

shore (Cummings and others, 1984). Dunes provide areas of 

recharge; however, most are located above the water table 

(Giroux and others, 1964). Post‐glacial lacustrine deposits are 

delineated from glaciolacustrine deposits by the presence of 

shorelines on all sides and a large amount of organic mat‐

ter. Post‐glacial lacustrine deposits are present in Pine Grove 

Township and near the intersection of Waverly, Arlington, 

and Colombia Townships. Alluvium is composed of sand and 

gravel and is limited in extent. Post‐glacial deposits are gener‐

ally hydraulically connected to the glacial deposits (Cum‐

mings and others, 1984).

In the Michigan Basin, the glacial aquifer consists of 

sand and gravel that is part of a thick sequence of Pleisto‐

cene glacial deposits. With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). In Van Buren County, the 

thickness of glacial deposits ranges from 100 to 600 ft thick 

(Giroux and others, 1964; Cummings and others, 1984). The 

glacial deposits are composed of outwash, till, and glaciola‐

custrine deposits. Sand and gravel outwash supplies the largest 

quantity of water to wells. A large deposit of outwash trends 

southwest, near Keeler, and extends northeast near Lawrence. 

The estimated transmissivity for the sand and gravel aquifer 

ranges from approximately 2,675 to 20,050 ft2/day.

Till is composed of clay, silt, sand, and gravel in vari‐

ous proportions. The yield from till deposits varies, but it 

is generally less than the yield from outwash. Till deposits 

generally occur in moraines and till plains (Giroux and oth‐

ers, 1964). Giroux and others (1964) observed that glacial till 

has an estimated transmissivity near 133 ft2/day. According 

to the Public Water Supply database, the estimated transmis‐

sivity for wells completed in till in Van Buren County ranges 

from approximately 5,220 to 10,360 ft2/day. Till plains are 

dispersed throughout the county, and three morainic systems 

are present: the Kalamazoo, Valparaiso, and Lake Border 

Moraines. The Kalamazoo Moraine is located in the southern 

part of the county, and consists of three ridges connected with 

cross ridges. The area in between the ridges of the moraine 

is covered with outwash. The Kalamazoo Moraine is com‐

prised predominately of sand and gravel, often covered with 

boulder‐rich, clay till, and underlain with areas of clay‐rich 

till. The Valparaiso Moraine covers the majority of the county. 

It is a single broad moraine trending from the south, and 

extends into three ridges in the north. The Valparaiso Moraine 

is predominately sand and gravel with areas of silt and clay. 

Boulders are also present in the moraine. The Lake Border 

Moraine parallels the shoreline of Lake Michigan a few miles 

inland. Ridges in the moraine are composed of clayey till, 

with lenses of sand and gravel. Glacial lacustrine deposits are 

present in the western and northwestern portions of the county 

(Terwillinger, 1954). Glacial lacustrine deposits are composed 

of sand, silt, and clay. The glaciolacustrine deposits do not 

yield large amounts of water. Van Buren County tends to have 

hard to very hard ground water. The exception is in the north‐

western portion of the county. Water from the glacial deposits 

also has high concentrations of iron, chloride, and nitrate in 

certain areas of the county (Giroux and others, 1964).

Bedrock underlies the glacial deposits. The bedrock 

surface is composed of the Coldwater Shale. The Coldwater 

Shale ranges between 300 to 600 ft thick in Van Buren County, 

and is primarily composed of shale, along with some lime‐

stone. The Coldwater Shale generally yields small quantities 

of water that may be saline, generally from the limestone in 

the unit (Giroux and others, 1964).

Washtenaw County

Washtenaw County is in the southeastern portion of 

the Lower Peninsula of Michigan. Economically important 

resources in the county are related to the geology of the area. 

Oil and gas deposits are present in the bedrock units of the 

county due to a series of parallel anticlines that trend north‐

west to southeast across Washtenaw County. Glacial sand 

and gravel deposits are also abundant in the county, and these 

deposits often are mined. The potential for clay and peat min‐

ing is also present in the county.

Five watersheds are included in Washtenaw County. 

The Upper Grand, Huron, Detroit, Raisin, and Ottawa‐Stony 

watersheds are located in the northwestern, northern, north‐

east, southwest and central, and southeast portion of the 

county, respectively. According to the February 2005 Wellogic 

database, approximately 86 percent of the wells in Washtenaw 

County are completed in the glacial deposits, and 11 percent 

in the bedrock units. There is insufficient information to make 

this distinction for 3 percent of the wells in the county. Water 

from the glacial wells may be hard and contain high amounts 

of iron. The water quality of the bedrock aquifer varies, but 

County Summaries  69
may have high chloride and dissolved solids concentrations. 

The majority of the wells in the county are completed in gla‐

cial deposits.

Soils and glacial deposits that have relatively high perme‐

ability occur in areas of the county. However, surrounding 

these areas are regions where the surface is less permeable till 

or clay (Fleck, 1980). With the available information, glacial 

lithologies cannot be regionally correlated in the subsurface. 

This is likely due to the lateral and vertical heterogeneity of 

glacial deposits that resulted from a complex depositional 

history (Westjohn and others, 1994). Glacial deposits range 

in thickness from 50 to 400 ft in Washtenaw County. In 

the northwestern portion and areas in the southeast, glacial 

deposits are less than 100 ft thick. In the northeastern and 

central portion of Washtenaw County, the glacial deposits are 

commonly greater than 250 ft in thickness. Glacial deposits 

are composed of till, outwash, and lacustrine deposits. In the 

county, till is fine to coarse grained, and is present in moraines 

and till plains. Moraines are a combination of clay, silt, sand, 

and gravel. Outwash is composed of mostly sand and gravel. 

Moraines and outwash cover the majority of the county, except 

in the southeastern portion where lacustrine dominate.. Lacus‐

trine are generally composed of a thin sand layer underlain by 

clay and silt (Fleck, 1980).

Aquifers in the glacial deposits consist largely of sands 

and gravels and vary regionally in thickness and perme‐

ability. The ability to obtain water from the glacial deposits 

varies with location within the county. Twenter and others 

(1976) classified the glacial deposits of Washtenaw County 

as aquifer and nonaquifer materials. Aquifer materials consist 

of deposits that are permeable. Nonaquifer materials have 

low permeability. Low permeability glacial deposits include 

clay, hardpan, and heterogeneous fine‐grained deposits. In the 

northwest one and/or two aquifers are present in the glacial 

deposits. One aquifer is able to supply moderate to large yields 

of water, while in other areas a shallow aquifer also is present 

that supplies enough water for domestic use. A large portion 

of the glacial deposits in southwestern Washtenaw County is 

composed of aquifer materials and may yield large supplies of 

water. West and northwest of Ann Arbor, the aquifer materials 

are thick, but lenticular. These glacial deposits may be able to 

yield moderate to large amounts of water, but heavy pumping 

may deplete the water supply quickly. In the eastern portion 

of the county, aquifer materials occur in small lenses, and are 

probably sufficient for domestic supplies (Twenter and others, 

1976). It may therefore be difficult to obtain large quantities 

of water in Northfield, Salem, Superior, and Saline Town‐

ships; however, sufficient amounts of water may be available 

for domestic supplies (Borton, 1974). In Augusta Township, 

aquifer materials are scarce in the glacial deposits and even 

domestic supplies are difficult to obtain. (Twenter and others, 

1976).

Bedrock underlies the glacial deposits. The bedrock is 

composed of Mississippian and Devonian sedimentary rocks, 

which generally dip to the northwest. The units of that form 

the bedrock surface generally trend southwest to northeast 

along the surface and increase in age from the northwest to the 

southeast. The Mississippian bedrock units, from youngest to 

oldest, include the Michigan Formation, Marshall Sandstone, 

Coldwater Shale, Sunbury Shale, Berea Sandstone, and Bed‐

ford Shale (Twenter and others, 1976). The Michigan Forma‐

tion forms a very small discontinuous portion of the bedrock 

surface in the northwestern part of the county. The Michigan 

Formation is composed of shale that is limy and sandy in the 

lower portion of the formation (Twenter and others, 1976). 

The lower permeability lithologies of the Michigan Formation 

are considered a confining unit. The thickness of the Michigan 

confining unit ranges from less than 50 to 400 ft within the 

State (Westjohn and Weaver, 1998).

The Marshall Sandstone underlies the Michigan Forma‐

tion. The Marshall Sandstone consists of one or more strati‐

graphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzare‐

nite to sublitharenite. At the base of the Marshall Sandstone is 

a fine‐ to medium‐grained litharenite that ranges in thickness 

from 30 to 125 ft. Permeable sandstones in the Marshall Sand‐

stone comprise the Marshall aquifer. The Marshall aquifer 

ranges in thickness from 75 to greater than 200 ft within the 

State (Westjohn and Weaver, 1998).

The Marshall Sandstone is generally a productive aquifer 

(Fleck, 1980). The Marshall aquifer supplies fresh water in 

Washtenaw County (Westjohn and Weaver, 1996c). However, 

in a well in Lyndon and a well in Sylvan Township, Haack and 

Rachol (2000h), found the two highest arsenic concentrations 

in ground water for the county. Both these wells were com‐

pleted in Marshall Sandstone (Haack and Rachol, 2000h).

In the central portion of the county, the Coldwater Shale 

forms the bedrock surface (Fleck, 1980). The Coldwater Shale 

underlies the Marshall Sandstone and has very low permeabil‐

ity. The Coldwater Shale consists of shale, sandstone, silt‐

stone, and carbonates. This is generally considered a confining 

unit and ranges in thickness, from east to west across the State, 

from 500 to 1300 ft thick (Westjohn and Weaver, 1996b). The 

Coldwater Shale contains more sandstone and siltstone in the 

eastern portion of the basin and grades into more dolomitic 

deposits in the western portion of the basin (Monnett, 1948). 

In general, the Coldwater Shale does yield supplies of water, 

except for localized, thin lenses of sandstone that may yield 

enough water for domestic uses (McGuinness and others, 

1949).

The Sunbury Shale, Berea Sandstone, and Bedford Shale 

have not been differentiated at the bedrock surface and form 

the bedrock surface southeast of the Coldwater Shale. The 

Sunbury Shale underlies the Coldwater Shale (Fleck, 1980). 

The Sunbury Shale has very low permeability and does not 

yield adequate supplies of water (McGuinness and others, 

1949). However, according to Fleck, sandy lenses may provide 

70 Summary of Hydrogeologic Conditions by County for the State of Michigan
water supplies (1980). The Berea Sandstone underlies the 

Sunbury Shale and may provide water for domestic supplies in 

some areas (Fleck, 1980). However, in some areas the Berea 

Sandstone yields saline water (McGuinness and others, 1949). 

The Bedford Shale underlies the Berea Sandstone and except 

for sandy lenses is impermeable (Fleck, 1980).

The Devonian units that form the bedrock surface of 

Washtenaw County consist of the Antrim Shale, Traverse 

Group, Dundee Limestone, and Detroit River Group. The 

Antrim Shale underlies the Bedford Shale. The Antrim Shale 

is relatively impermeable except for sand lenses (Fleck, 1980). 

McGuinness and others noted that the Antrim Shale supplies 

moderately mineralized, soft water to Belleville municipal 

wells (1949). The Traverse Group consists of limestone and 

shale that may provide water for domestic use and also sup‐

plies oil and gas deposits. The Traverse Group may supply 

saline water (McGuinness and others, 1949). The Dundee 

Limestone underlies the Traverse Group and forms the bed‐

rock surface generally southeast of the Traverse Group in the 

southeastern portion of the county. The Dundee Limestone 

is composed of limestone and dolomite and may provide 

water for domestic supplies. Oil and gas are also found in the 

Dundee Formation. The Detroit River Group forms the bed‐

rock surface in the southeastern most portion of the county and 

consists of limestone, dolomite and evaporates. Gas is found 

in the Detroit River Group and the Detroit River Group may 

yield water for domestic supplies. The Sylvania Sandstone is 

the basal portion of the Detroit River Group. This is sandstone 

that often yields saline water (Fleck, 1980).

 Silurian and older rocks do not subcrop in Washtenaw 

County, but are present beneath the surface. Those that will 

be mentioned are the Bass Islands Group, the Salina Group, 

and the Niagara Group. The Bass Islands Group underlies the 

Sylvania Sandstone, and consists of dolomite. Water from 

wells tapping the Bass Islands Group may be mineralized and 

some areas contain hydrogen sulfide (McGuinness and others, 

1949). The Salina Group underlies the Bass Islands Group 

and is composed of limestone, dolomite, and evaporites. In the 

northern portion of the county, the Salina Group contains salt 

beds that up to 400 ft thick. The underlying Niagara Group 

consists of limestone and dolomite. The Niagara Group con‐

tains oil and gas (Fleck, 1980).

Wayne County

Wayne County is in the southeastern portion of the Lower 

Peninsula of Michigan. Lake St. Clair, Detroit, and Huron 

watersheds drain the county. Lake St. Clair watershed crosses 

the northeastern portion of the county, while the Detroit water‐

shed covers the majority of the county. The Huron watershed 

trends northwest to southeast, south of the Detroit watershed, 

and the Ottawa‐Stony watershed crosses the southwestern 

corner of the county. According to the February 2005 Wellogic 

database, approximately 67 percent of the wells in Wayne 

County are completed in the glacial deposits, and 27 percent 

in the bedrock units. There is insufficient information to make 

this distinction for 6 percent of the wells in the county.

The uppermost potential aquifer material is alluvium. 

Alluvium ranges from 0 to 75 ft in thickness in areas of Wayne 

County. These deposits consist of clay, silt, sand, and gravel. 

Water obtained from wells that tap alluvium may be hard, but 

the quality is generally good.

Glacial deposits underlie the alluvium in the county, if 

alluvium is present. In the Michigan Basin, glacial aquifers 

consist of sand and gravel that are part of a thick sequence 

of Pleistocene glacial deposits. With the available informa‐

tion, glacial lithologies cannot be regionally correlated in 

the subsurface. This is likely due to the lateral and vertical 

heterogeneity of glacial deposits that resulted from a complex 

depositional history (Westjohn and others, 1994). Glacial 

deposits range in thickness from 20 to 400 ft in Wayne County 

(Mozola, 1969). Most of the county is covered in lacustrine 

deposits. The lacustrine deposits are composed of primar‐

ily clay and sand. Till, composed of clay, silt, sand, gravel, 

and boulders, also is present in the county. Moraines and till 

plains range in thickness from 180 to 400 ft, and are primarily 

composed of glacial till. Isolated sand and gravel deposits may 

be interspersed within the till. Two moraines are present in 

the northwest corner of the county. These moraines are named 

the Outer Defiance and the Inner Defiance. These moraines 

trend northeast to southwest and are separated by an outwash 

deposit. Outwash deposits are primarily composed of sand 

and gravel. The water from outwash deposits may be hard 

(Mozola, 1969). According to the Public Water Supply data‐

base, the estimated transmissivity for a glacial well in Wayne 

County is approximately 56,330 ft2/day.

Bedrock underlies the glacial deposits in Wayne County. 

The bedrock in Wayne County consists primarily of Missis‐

sippian and Devonian aged units and includes (in descending 

order) the Coldwater Shale, Sunbury Shale, Berea Sandstone, 

Bedford Shale, Antrim Shale, Traverse Group, Dundee Lime‐

stone, and Detroit River Group. The bedrock units generally 

trend northeast to southwest, and dip to the northwest. The 

youngest bedrock units subcrop in the northwestern part of 

the county and are successively older towards the southeastern 

portion of the county (Mozola, 1969). Water from bedrock 

wells may be mineralized in this region (Twenter and others, 

1975).

 The Coldwater Shale is the youngest bedrock unit in 

Wayne County. The Coldwater and Sunbury Shales form 

the bedrock surface in a small area along the eastern edge of 

Wayne County (Mozola, 1969). The Coldwater Shale consists 

of shale, sandstone, siltstone, and carbonates. This is con‐

sidered to be a confining unit in most of the State and ranges 

in thickness, from east to west, from 500 to 1,300 ft. The 

Coldwater Shale contains more sandstone and siltstone in the 

eastern portion of the Michigan Basin and grades into more 

dolomitic deposits in the western portion of the basin (Mon‐

nett, 1948). However, in most of the State the Coldwater Shale 

does not contribute a significant amount of ground water to 

the region (Westjohn and Weaver, 1996b). The Sunbury Shale 

County Summaries  71
underlies the Coldwater Shale. The Sunbury Shale is generally 

slightly calcareous with areas of pyrite. The Sunbury Shale 

yields little if any water that is mineralized with depth.

The Berea Sandstone underlies the Sunbury Shale. The 

Berea Sandstone consists of two to three sandstones sepa‐

rated by shale. The upper unit is fine‐grained, cemented, silty 

and/ or shaly, dolomitic sandstone that contains micas and 

pyrite in areas. The middle unit is more friable and consists 

of fine‐ to medium‐grained sandstone with beds of shale and 

well‐cemented sandstone. The lower unit is a fine‐grained, 

cemented silty and/ or shaly, dolomitic sandstone that contains 

micas and pyrite in areas, but contains less pyrite and more 

shale (Ferris and others, 1954). In the region where the Berea 

Sandstone forms the bedrock surface, yields from these wells 

are generally adequate for domestic use (Twenter and others, 

1975). However, saline water has been recorded in wells tap‐

ping the Berea Sandstone in Oakland County near 1,000 ft in 

depth (Mozola, 1954). The Bedford Shale underlies the Berea 

Sandstone. The Bedford Shale consists of shale, sandy shale, 

and shaly limestone (Ferris and others, 1954). The Bedford 

Shale does not yield much, if any, water to wells.

 The Antrim Shale underlies the Bedford Shale. The Ant‐

rim Shale is composed of shale with concretions of pyrite and 

possibly anthraconite and marcasite are present in the Antrim 

Shale (Ferris and others, 1954; Nicholas and others, 1996). 

The Traverse Group comformably underlies the Antrim Shale. 

Pyrite is present throughout the Traverse Group, which con‐

sists of beds of shale, limestone, and dolomite. The Dundee 

Limestone unconformably underlies the Traverse Group. Inter‐

bedded limestone and dolomite compose the Dundee Lime‐

stone. The limestone contains small vugs and the dolomite 

contains vugs and fractures. Celestite and calcite are minerals 

that are present in the vugs. Sulfur was found to occur in the 

fractures at shallow depths in areas of nearby Monroe County 

(Nicholas and others, 1996).

The Detroit River Group unconformably underlies the 

Dundee Limestone. Sinkholes from this formation are pres‐

ent in Monroe County. Interbedded limestone and dolomite 

compose the upper Detroit River Group. The limestone con‐

tains small vugs and the dolomite contains vugs and fractures. 

Celestite and calcite are minerals that are present in the vugs. 

Sulfur occurs in the fractures at shallow depths in this unit in 

Monroe County. The Sylvania Sandstone is the basal portion 

of the Detroit River Group and is a calcite cemented, moder‐

ately to well sorted, quartz sandstone. Pyrite, celestite, calcite, 

and sulfur are present in areas of the sandstone (Nicholas and 

others, 1996). The Sylvania Sandstone is the oldest bedrock 

unit that subcrops in Wayne County (Mozola, 1969). In the 

region where it forms the bedrock surface, yields from the 

Sylvania Sandstone wells are generally sufficient for domestic 

use (Twenter and others, 1975).

Wexford County

Wexford County is located in the northwestern portion 

of the Lower Peninsula of Michigan. The Muskegon and 

Manistee watersheds drain Wexford County. According to the 

February 2005 Wellogic database, approximately 98 percent 

of the wells in Wexford County are completed in the glacial 

deposits, and less than 1 percent in the bedrock units. There is 

insufficient information to make this distinction for 2 percent 

of the wells in the county.

With the available information, glacial lithologies cannot 

be regionally correlated in the subsurface. This is likely due 

to the lateral and vertical heterogeneity of glacial deposits that 

resulted from a complex depositional history (Westjohn and 

others, 1994). The glacial deposits in Wexford County range in 

thickness from 201 to greater than 1,000 ft (Western Michigan 

University, 1981). The glacial deposits in Wexford County 

consist of outwash, till, and lacustrine deposits (Stewart, 1948; 

Farrand and Bell, 1982). Outwash deposits are abundant in 

the county and are generally underlain by well‐jointed clayey 

till. Till occurs in till plains and moraines. The Lake Border 

Moraine covers the largest area in Wexford County. In the 

southeastern portion of the county, the Valparaiso and Char‐

lotte Moraines are present. These are part of the Lake Michi‐

gan‐Saginaw Interlobate tract. The Port Huron Moraine covers 

a small area in the north‐central portion of the county. The till 

within the moraines contains abundant boulders, sand, and 

silt near the surface (Stewart, 1948). This till is classified as 

coarse‐textured (Farrand and Bell, 1982). Underlying the till is 

an older clayey till (Stewart, 1948). Sand and gravel lacustrine 

deposits are present on the surface in the southeastern portion 

of the county, near Cadillac (Farrand and Bell, 1982). Sand 

dunes are common on the surface of glacial features through‐

out the county (Stewart, 1948).

Glacial aquifers consist of sand and gravel that are part of 

a thick sequence of Pleistocene glacial deposits (Westjohn and 

others, 1994). These sand‐and‐gravel aquifers supply water 

to the City of Cadillac and other users in Wexford County 

(Baltusis and others, 1992). Exploratory drilling indicated 

three sand‐and‐gravel aquifers in the Cadillac area. Clay‐con‐

fining units separate the aquifers (Hoard and Westjohn, 2005). 

Based on aquifer test results for the City of Cadillac, the deep 

aquifer, which is over 265 feet below the ground surface, 

has a hydraulic conductivity of 214 ft/day (Jones, Henry and 

Williams Consulting Engineers, 1959), J.L. Wilcox & Associ‐

ates (1986) conducted aquifer tests for production wells in 

Haring Township, which is just north of the City of Cadillac. 

These tests indicate that the deep aquifer underlying Haring 

Township has similar hydraulic properties to the deep aquifer 

underlying Cadillac. Results from other aquifer tests within 

the Cadillac area indicate horizontal hydraulic conductivities 

ranging from 43 to 163 ft/d for the shallow and intermediate 

aquifers in the glacial deposits and a vertical hydraulic con‐

ductivity of 0.031 ft/day for the clay‐confining unit between 

the intermediate and deep glacial aquifers (Hoard and West‐

john, 2005). According to the Public Water Supply database, 

72  Summary of Hydrogeologic Conditions by County for the State of Michigan
the estimated transmissivity, based on aquifer tests, for glacial 

wells ranges from approximately 2,265 to 51,895 ft2/day.

 Bedrock underlies the glacial deposits. The bedrock 

surface of Wexford County is composed of the Saginaw For‐

mation, Bayport Limestone, Michigan Formation, Marshall 

Sandstone, and Coldwater Shale (Milstein, 1987). The Sagi‐

naw Formation forms the bedrock surface in the southeastern 

portion of Wexford County, and is composed of interbedded 

sandstone, siltstone, shale, coal, and limestone. The Saginaw 

aquifer consists of hydraulically connected sandstones in the 

Saginaw Formation (Westjohn and Weaver, 1996a). Within 

the State, the Saginaw aquifer ranges less than 100 to 370 ft 

thick, and yields fresh and saline water in areas of the State. 

The Saginaw aquifer contains fresh water in Wexford County 

(Westjohn and Weaver, 1996c). The Saginaw confining unit 

underlies the Saginaw aquifer. The Saginaw confining unit is 

approximately less than 100 to 240 ft thick within the State, 

and is mostly shale, with thin layers of discontinuous sand‐

stone, siltstone, limestone, and coal. The permeable layers 

within the Saginaw confining unit appear to be isolated from 

the regional ground‐water‐flow system (Westjohn and Weaver, 

1996a).

The Saginaw confining unit separates the Saginaw aqui‐

fer from the underlying Parma‐Bayport aquifer. The Parma 

Sandstone is often considered the basal unit of the Saginaw 

Formation, although the stratigraphic relationship is not 

clear between the Saginaw Formation, Parma Sandstone, and 

Mississippian‐aged Bayport Limestone. The Parma Sandstone 

is composed of medium‐ to coarse‐grained sandstone, and 

is generally less than 100 ft thick (Cohee and others, 1951). 

The Bayport Limestone is a fossiliferous, cherty limestone, 

often with interbedded sandstone and varies considerably 

in thickness from one area to another. The Bayport Lime‐

stone and Parma Sandstone appear to interfinger throughout 

the Michigan Basin (Westjohn and Weaver, 1996a). These 

units are hydraulically connected, and together they form 

the Parma‐Bayport aquifer (Westjohn and Weaver, 1996a). 

The Parma‐Bayport aquifer is approximately 100 to 150 ft 

thick within the Michigan Basin. Please note that due to the 

uncertainty of stratigraphic relationship between these units, 

in other reports this aquifer may be delineated differently. 

The Parma‐Bayport aquifer contains fresh and saline water in 

Wexford County (Westjohn and Weaver, 1996c).

The Michigan Formation underlies the Bayport Lime‐

stone. The Michigan Formation is composed of sandstone, 

shale, limestone, and occasional dolomite. Gypsum and anhy‐

drite are also present in the formation. The lower permeability 

lithologies of the Michigan Formation are considered to be a 

confining unit that separates the Parma‐Bayport aquifer from 

the underlying Marshall aquifer. The Michigan confining unit 

is approximately 50 to 400 ft thick in the State (Westjohn and 

Weaver, 1996b).

 The Marshall Sandstone underlies the Michigan For‐

mation. The Marshall Sandstone consists of one or more 

stratigraphically continuous permeable sandstones. The upper 

sandstone is a quartzarenite to sublitharenite that is referred to 

as the Napoleon Sandstone Member. A shale, siltstone, and/or 

carbonate layer separates the Napoleon Sandstone Member 

from the underlying lower Marshall sandstone. The lower 

Marshall sandstone is comprised of two units. The upper unit 

is generally 50 to 125 ft of fine‐ to medium‐grained quartzare‐

nite to sublitharenite. At the base of the Marshall Sandstone is 

a fine‐ to medium‐grained litharenite that ranges in thickness 

from 30 to 125 ft. Permeable sandstones in the Marshall Sand‐

stone comprise the Marshall aquifer. The Marshall aquifer 

ranges in thickness from 75 to greater than 200 ft within the 

State (Westjohn and Weaver, 1998). The Marshall Sandstone 

contains fresh and saline water, as well as, brine in Wexford 

County (Westjohn and Weaver, 1996c).

The Coldwater Shale underlies the Marshall Sandstone. 

The Coldwater Shale consists of primarily shale with interbeds 

or lenses of sandstone, siltstone, and dolomite. The Coldwater 

Shale is relatively impermeable and is considered a confin‐

ing unit in most of Michigan (Westjohn and Weaver, 1996b). 

These bedrock units have not been used for water supply 

because the overlying glacial deposits which consist predomi‐

nantly of permeable sand and gravel provide enough water for 

industrial, commercial, and domestic uses (Hoard and West‐

john, 2005).

 References Cited

Aichele, S., Hill‐Rowley, R., and Malone, M., 1998, Arsenic, 

nitrate, and chloride in ground water, Oakland County, 

Michigan: U.S. Geological Survey Fact Sheet 135‐98, 6 p.

Aichele, S. S., 2000, Ground‐water quality atlas of Oakland 

County, Michigan.: U.S. Geological Survey Water‐Re‐

sources Investigations Report 00‐4120, 53 p.

Allen, W. B., 1974, Flowing wells in Michigan: Michigan 

Geological Survey Division Report W 2, 27 p.

Allen, W. B., Miller, J. B., and Wood, W. W., 1972, Availabil‐

ity of water in Kalamazoo County, southwestern Michigan: 

U.S. Geological Survey Water‐Supply 1973, 129 p.

Baltusis, M. A., Quigley, M. F., and Mandle, R. J., 1992, 

Municipal ground‐water development and withdrawals in 

the central Lower Peninsula of Michigan, 1870‐1987: U.S. 

Geological Survey Open‐File Report 91‐215, 89 p.

Barton, G., 1995, Contributing areas of water‐supply wells in 

Elkton and Pigeon, Huron County, MI: U.S. Geological Sur‐

vey Water‐Resources Investigations Report 94‐4089, 10 p.

Barton, G. J. and Grannemann, N. G., 1998, Water resources 

of Lac Vieux Desert Indian community and vicinity, west‐

ern Upper Peninsula, Michigan: U.S. Geological Survey 

Water‐Resources Investigations Report 98‐4051, 15 p.

 References Cited  73
Bayless, E., Reeves, H., Arihood, L., Lampe, D., Brown, S., 

Kincare, K., Newell, W., O’Leary, D., and Stone, B., 2005, 

Automated Construction of Hydrostratigraphic Models for 

Ground‐Water Flow and Transport Simulations at Elkhart 

County, Indiana and Berrien County, Michigan: U.S. Geo‐

logical Survey Scientific Investigations Report in prepara‐

tion.

Blewett, W. L. and Winters, H. A., 1995, The importance 

of glaciofluvial features within Michigan’s Port Huron 

moraine: Annals of the Association of American Geogra‐

phers, vol. 85, no. 2, p. 306‐319.

Borton, T. E., 1974, Planning perspectives on water resources: 

Washtenaw County, Michigan: Washtenaw County Metro‐

politan Planning Commission Report M 9, 357‐384 p.

Boutt, D. F., 1999, Interpreting the Impacts of Land Use on 

Water Quality Using Groundwater Flow and Transport 

Simulations in the Grand Traverse Bay Watershed: East 

Lansing, Michigan, Michigan State University, M.S. Thesis, 

112 p.

Brannen, J. R., 1997, Hydrogeology of four Sault Ste. Marie 

tribal communities in the Upper Peninsula of Michigan: 

U.S. Geological Survey Fact Sheet 009‐97, 4 p.

Brewer, M. K., 1991, A regional study of ground‐water quality 

in Barry County, Michigan: Kalamazoo, Michigan, Western 

Michigan University, M.S. Thesis, 125 p.

Brown, E. A. and Stuart, W. T., 1951, Ground‐water resources 

of the glacial deposits, Bessemer area, Michigan: Michigan 

Geological Survey Division Report P 14, 68 p.

Caetta, M. A., 1991, An investigation of possible subsurface 

brine springs in southeastern Lenawee County, Michigan: 

Akron, Ohio, The University of Akron, M.S. Thesis, 107 p.

Catacosinos, P. A., D. B., H., Reynolds, R. F., Westjohn, D. 

B., and Wollensack, M. D., 2001, Stratigraphic Lexicon for 

Michigan: Michigan Geological Survey Division and Michi‐

gan Basin Geological Society Report B 8, 56 p.

Cathcart, R. S., 1982, Compensating for adverse operating 

conditions in a karstic limestone deposit: Michigan Basin 

Geological Society, p. 119‐125.

Chowdhury, S. H., 1999, A Comprehensive Approach for 

Evaluation of Groundwater Vulnerability to Contamination: 

Kalamazoo, Michigan, Western Michigan University, Ph.D. 

Dissertation, 124 p.

Cohee, G. V., Macha, C., and Holk, M., 1951, Thickness and 

lithology of Upper Devonian and Carboniferous rocks in 

Michigan: U.S. Geological Survey Report OC‐41.

Cummings, T. R., Gillespie, J. L., and Grannemann, N. G., 

1990, Hydrology and Land Use in Grand Traverse County, 

Michigan: U.S. Geological Survey Water‐Resources Investi‐

gations Report 90‐4122, 99 p.

Cummings, T. R. and Twenter, F. R., 1986, Assessment of 

ground‐water contamination at Wurtsmith Air Force base, 

Michigan, 1982‐85: U.S. Geological Survey Water‐Re‐

sources Investigations Report 86‐4188, 110 p.

Cummings, T. R., Twenter, F. R., and Holtschlag, D. J., 1984, 

Hydrology and land use in Van Buren County, Michigan: 

U.S. Geological Survey Water‐Resources Investigations 

Report 84‐4112, 124 p.

Deutsch, M., Burt, E. M., and Vanlier, K. E., 1958, Summary 

of ground water investigations in the Holland Area, Michi‐

gan: Michigan Geological Survey Division Report P 20, 

87 p.

Deutsch, M., Vanlier, K. E., and Giroux, P. R., 1960, 

Ground‐water hydrology and glacial geology of the Kalam‐

azoo area, Michigan: Michigan Geological Survey Division 

Report P 23, 122 p.

Doonan, C. J. and Byerlay, J. R., 1973, Ground water and 

geology of Baraga County, Michigan: Michigan Geological 

Survey Division Report W 11, 26 p.

Doonan, C. J., Hendrickson, G., and Byerlay, J., 1970, 

Groundwater and geology of the Keweenaw Peninsula, 

Michigan: Michigan Geological Survey Division Report W 

10, 41 p.

Doonan, C. J. and Hendrickson, G. E., 1967, Ground water in 

Iron County, Michigan: Michigan Geological Survey Divi‐

sion Report W 7, 59 p.

Doonan, C. J. and Hendrickson, G. E., 1968, Ground water in 

Gogebic County, Michigan: Michigan Geological Survey 

Division Report W 8, 22 p.

Doonan, C. J. and Hendrickson, G. E., 1969, Ground water in 

Ontonagon County, Michigan: Michigan Geological Survey 

Division Report W 9, 29 p.

Doonan, C. J. and VanAlstine, J. L., 1982, Ground water and 

geology of Marquette County, Michigan: U.S. Geological 

Survey Open‐File Report 82‐501, 46 p.

Engineering for Earth, Water, and Air Resources, Inc., 1987, 

Phase two: Site investigation of the Kingsford site, Kings‐

ford, Michigan: Ford Motor Company, Tech. Rep. Con‐

sultant Report vol. 1 and 2, variously paginated., cited by 

Luukkonen, C. L. and Westjohn, D. B., 2000, Ground‐Water 

Flow and Contributing Areas to Public‐Supply Wells in 

Kingsford and Iron Mountain, Michigan: U.S. Geological 

Survey Water‐Resources Investigations Report 00‐4226.

74  Summary of Hydrogeologic Conditions by County for the State of Michigan
Ervin, J. L. and Kittleson, K. M., 1988, Assessment of rural 

groundwater contamination by agriculture chemicals in 

sensitive areas of Michigan: Institute of Water Research 

and Department of Resource Development, Michigan State 

University, Report Grant No. 14‐08‐0001‐G1429, 51 p.

Farrand, W. R. and Bell, D. L., 1982, Quaternary Geology of 

Southern Michigan: Department of Geological Sciences, 

University of Michigan, map, Ann Arbor, Michigan, 1 

sheet, scale 1:500,000, available from http://www.michigan.

gov/cgi.

Ferris, J. G., Burt, E. M., Stramel, G. J., and Croswaite, E., 

1954, Ground‐water resources of southeastern Oakland 

County, MI: Michigan Geological Survey Division Report P 

16, 158 p.

Fleck, W. B., 1980, Geology and hydrology for environmental 

planning in Washtenaw County, Michigan: U.S. Geological 

Survey Open‐File Report unnumbered, 23 p.

Gardner, W. C., 1974, Middle Devonian stratigraphy and 

depositional environments in the Michigan Basin: Special 

Papers ‐ Michigan Basin Geological Society, vol. 1, p. 46.

Gillespie, J. L. and Dumouchelle, D. H., 1989, Ground‐water 

flow and quality near the Upper Great Lakes connecting 

channels, Michigan.: U.S. Geological Survey Water‐Re‐

sources Investigations Report 88‐4232, 82 p.

Giroux, P. R., Hendrickson, G. E., Stoimenoff, L. E., and 

Whetstone, G. W., 1964, Water resources of Van Buren 

County, Michigan: Michigan Geological Survey Division 

Report W 3, 144 p.

Giroux, P. R., Stoimenoff, L. E., Nowlin, J. O., and Skinner, 

E. L., 1966, Water resources of Branch County Michigan: 

Michigan Geological Survey Division Report W 6, 158 p.

Grannemann, N. G., 1979, Water Resources of the Mar‐

quette Iron Range area, Marquette County, Michigan: U.S. 

Geological Survey Water‐Resources Investigations Report 

79‐1339, 77 p.

Grannemann, N. G., 1984, Hydrogeology and effects of tail‐

ings basins on the hydrology of Sands Plain, Marquette 

County, Michigan: U.S. Geological Survey Water‐Re‐

sources Investigations Report 84‐4114, 98 p.

Grannemann, N. G. and Twenter, F. R., 1982, Ground‐water 

supply for public water at Windigo, Isle Royale National 

Park, Michigan: U.S. Geological Survey Open‐File Report 

82‐567, 16 p.

Grannemann, N. G. and Twenter, F. R., 1985, Geohydrology 

and ground‐water flow at Verona well field, Battle Creek, 

Michigan: U.S. Geological Survey Water‐Resources Investi‐

gations Report 85‐4056, 54 p.

Gutschick, R. and Sandberg, C., 1991, Upper Devonian bio‐

stratigraphy of the Michigan Basin: \it in \/Catacosinos, P. 

A. and Daniels, P. A., Jr., eds., Early Sedimentary Evolution 

of the Michigan Basin:, Geological Society of America, 

Special Paper 256, p. 155‐179.

Haack, S. and Rachol, C. M., 2000a, Arsenic in ground water 

in Sanilac County: U.S. Geological Survey Fact Sheet 

FS 132‐00.

Haack, S. K. and Rachol, C. M., 2000b, Arsenic in ground 

water in Genesee County, Michigan: U.S. Geological Sur‐

vey Fact Sheet FS 127‐00.

Haack, S. K. and Rachol, C. M., 2000c, Arsenic in ground 

water in Huron County, Michigan: U.S. Geological Survey 

Fact Sheet 128‐00.

Haack, S. K. and Rachol, C. M., 2000d, Arsenic in ground 

water in Lapeer County, Michigan: U.S. Geological Survey 

Fact Sheet FS 129‐00.

Haack, S. K. and Rachol, C. M., 2000e, Arsenic in ground 

water in Livingston County, Michigan: U.S. Geological 

Survey Fact Sheet FS 130‐00.

Haack, S. K. and Rachol, C. M., 2000f, Arsenic in ground 

water in Shiawassee County: U.S. Geological Survey Fact 

Sheet FS 131‐00.

Haack, S. K. and Rachol, C. M., 2000g, Arsenic in ground 

water in Tuscola County: U.S. Geological Survey Fact 

Sheet FS 133‐00.

Haack, S. K. and Rachol, C. M., 2000h, Arsenic in ground 

water in Washtenaw County, Michigan: U.S. Geological 

Survey Fact Sheet FS 134‐00.

Haack, S. K. and Treccani, S. L., 2000, Arsenic concentra‐

tions and selected geochemical characteristics for ground 

water and aquifer materials in southeastern Michigan: U.S. 

Geological Survey Water‐Resources Investigations Report 

00‐4171, 38 p.

Handy, A. H., 1982, Water quality of coal deposits and aban‐

doned mines, Saginaw, County, Michigan: U.S. Geological 

Survey Open‐File Report 82‐511, 35 p.

Handy, A. H. and Stark, J. R., 1984, Water Resources of 

Sleeping Bear Dunes National Lakeshore, Michigan.: 

Water Resources Investigations, U.S. Geological Survey 

Water‐Resources Investigations Report 83‐4253, 39 p.

Handy, A. H. and Twenter, F. R., 1985, Water resources of Pic‐

tured Rocks National Lakeshore, Michigan: U.S. Geological 

Survey Water‐Resources Investigations Report 85‐4103, 

41 p.

 References Cited  75
Harrell, J. A., Hatfield, C. B., and Gunn, G. R., 1991, Missis‐

sippian system of the Michigan Basin; stratigraphy, sedi‐

mentology, and economic geology: \it in \/Catacosinos, P. 

A. and Daniels, P. A., Jr., eds., Early sedimentary evolution 

of the Michigan Basin:, Geological Society of America, 

Special Paper 256, p. 203‐219.

Hendrickson, G. E. and Doonan, C. J., 1966, Ground‐water 

resources of Dickinson County, Michigan: Michigan Geo‐

logical Survey Division Report W 5, 49 p.

Hoard, C. J. and Westjohn, D. B., 2001, Simulated effects of 

pumping irrigation wells on ground‐water levels in west‐

ern Saginaw County, Michigan: U.S. Geological Survey 

Water‐Resources Investigations Report 01‐4227, 25 p.

Hoard, C. J. and Westjohn, D. B., 2005, Simulation of 

ground‐water flow and areas contributing ground water to 

production wells, Cadillac, Michigan: U.S. Geological Sur‐

vey Scientific Investigations Report 2004‐5175, 18 p.

Holtschlag, D. J. and Luukkonen, C. L., 1997, Vulnerability of 

ground water to atrazine leaching in Kent County, Michi‐

gan: U.S. Geological Survey Water‐Resources Investiga‐

tions Report 96‐4198, 49 p.

Holtschlag, D. J. and Luukkonen, C. L., 1998, Assessment 

of ground‐water vulnerability to atrazine leaching in Kent 

County Michigan: Review, comparison to the results of 

other studies, and verification: U.S. Geological Survey 

Water‐Resources Investigations Report 98‐4006, 40 p.

Holtschlag, D. J., Luukkonen, C. L., and Nicholas, J. R., 1996, 

Simulation of ground‐water flow in the Saginaw Aquifer 

within Clinton, Eaton, and Ingham Counties: U.S. Geologi‐

cal Survey Water Supply Paper 2480, 49 p.

J.L. Wilcox and Associates, 1986, Report of well performance 

test Haring Township production well no. 1, Wexford 

County , Michigan: J.L. Wilcox and Associates, Report, 

variously paginated.

Jones, Henry, and Williams Consulting Engineers, 1959, 

Cadillac, Michigan: Water Improvements Report: Jones, 

Henry, and Williams Consulting Engineers, Report, vari‐

ously paginated.

Kehew, A. E., Nicks, L. P., and Straw, W. T., 1999, Palimpsest 

tunnel valleys: evidence for relative timing of advances in 

an interlobate area of the Laurentide ice sheet: Annals of 

Glaciology, vol. 28, p. 47‐52.

Kehew, A. E., Passero, R. N., Krishnamurthy, R. V., Lovett, 

C. K., Betts, M. A., and Dayharsh, B. A., 1998, Hydrogeo‐

chemical interaction between a wetland and an unconfined 

glacial drift aquifer, southwestern michigan: Ground Water, 

vol. 36, no. 5, p. 849‐856.

Kehew, A. E., Straw, W. T., Steinmann, W. K., Barrese, P. 

G., Passarella, G., and Peng, W.‐S., 1996, Ground‐water 

quality and flow in a shallow glacial aquifer impacted by 

agricultural contamination: Ground Water, vol. 34, no. 3, 

p. 491‐500.

Kellogg, R. L., 1964, A geophysical investigation of the 

hydrogeological characteristics of the Udell Hills area, 

Manistee County, Michigan: East Lansing, Michigan, 

Michigan State University, M.S. Thesis, 74 p.

Kimmel, R. E., 1983, Karst lakes of northeastern lower Michi‐

gan: Michigan Basin Geological Society, p. 82‐90.

Knutilla, R. L., 1969a, Water resources of the Belle River 

Basin: U.S. Geological Survey Hydrologic Atlas 317, 1 p.

Knutilla, R. L., 1969b, Water resources of the Pine River 

Basin, southeastern Michigan: U.S. Geological Survey 

Hydrologic Atlas 327, 1 p.

Knutilla, R. L., 1970, Water resources of the Black River 

Basin: U.S. Geological Survey Hydrologic Atlas 338, 3 p.

Knutilla, R. L. and Allen, W. B., 1975, Water Resources of the 

River Raisin Basin, southeastern Michigan: U.S. Geological 

Survey Hydrologic Atlas 520.

Knutilla, R. L., Twenter, F. R., and Larson, R. W., 1971, Upper 

Rifle River Basin, northeastern lower Michigan: An evalua‐

tion of its water resources and hydrologic environment: U.S. 

Geological Survey Water Information Series Report 1, 66 p.

Leverett, F. and Taylor, F., 1915, The Pleistocene of Indiana 

and Michigan and history of the Great Lakes: U.S. Geologi‐

cal Survey, Monograph 53, 527 p.

Lilienthal, R. T., 1974, Subsurface geology of Barry County, 

Michigan: Michigan Geological Survey Division Report of 

Investigation 15, 36 p.

Livingston County Planning Department, 1993, Livingston 

County groundwater mapping project: Livingston County 

Planning Department Report, 64 p.

Luukkonen, C. L. and Westjohn, D. B., 2000, Ground‐Water 

Flow and Contributing Areas to Public‐Supply Wells in 

Kingsford and Iron Mountain, Michigan: U.S. Geological 

Survey Water‐Resources Investigations Report 00‐4226.

Lynch, E. and Grannemann, N., 1997, Geohydrology and sim‐

ulations of ground‐water flow at Verona well field, Battle 

Creek, Michigan: U.S. Geological Survey Water‐Resources 

Investigations Report 97‐4068, 45 p.

Mandle, R. J. and Westjohn, D. B., 1987, Preliminary interpre‐

tation of vertical electrical‐resistivity soundings in the Sagi‐

naw Valley, Michigan: U.S. Geological Survey Open‐File 

Report 87‐474, 45 p.

76  Summary of Hydrogeologic Conditions by County for the State of Michigan
Mandle, R. J. and Westjohn, D. B., 1989, Geohydrologic 

framework and ground‐water flow in the Michigan Basin: 

American Water Resources Association, p. 83‐109.

Matthews, R. D., 1993, Review and revision of the Devoni‐

an‐Mississippian stratigraphy in the Michigan Basin: \it in 

\/Roen, J. B. and Kepferle, R. C., eds., Petroleum Geology 

of the Devonian and Mississippian Black Shale of Eastern 

North America:, U.S. Geological Survey Bulletin 1909, 

p. D1‐D85.

McDonald, M. G., 1980, Hydraulic characteristics of an under 

drained irrigation circle, Muskegon County waste‐water dis‐

posal system, Michigan: U.S. Geological Survey Open‐File 

Report 80‐773, 14 p.

McDonald, M. G. and Fleck, W. B., 1978, Model Analysis of 

the impact on ground‐water conditions of the Muskegon 

County wastewater disposal system, Michigan: U.S. Geo‐

logical Survey Open‐File Report 78‐99, 63 p.

McGuinness, C. L., Poindexter, O. F., and Otton, E. G., 1949, 

Ground‐water supplies of the Ypsilanti area, Michigan: U.S. 

Geological Survey Water‐Supply Paper 1078, 103 p.

Melhorn, W. N., 1954, Valders glaciation of the southern 

peninsula of Michigan: Ann Arbor, Michigan, University of 

Michigan, Ph.D. Dissertation.

Michigan State Legislature, 2003, Act No. 148 of Public Acts 

of 2003: Michigan State Legislature, 92nd, 5 p., accessed 

December 5, 2005 at http://www.deq.state.mi.us/documents/

deq‐wd‐gwcac‐PA148.pdf.

Michigan Water Resources Commission, 1960, Water resource 

conditions and uses in the Tittabawassee River Basin: Mich‐

igan Water Resources Commission Report W 60, 116 p.

Milstein, R. L., (comp.), 1987, Bedrock Geology of southern 

Michigan: Michigan Geological Survey, map, Lansing, 

Michigan, 1 sheet, scale 1:500,000, available from http://

www.michigan.gov/cgi.

Monaghan, G. W., Forstat, D. W., and Sorenson, H. O., 1983, 

Selected geologic maps of Kalamazoo County, Michigan: 

County geologic map series: Michigan Geologic Survey 

Division, Map.

Monnett, V. B., 1948, Mississippian Marshall formation of 

Michigan: Bulletin of the American Association of Petro‐

leum Geologists, vol. 32, no. 4, p. 629‐688.

Mozola, A. J., 1954, A survey of groundwater resources in 

Oakland County, Michigan, part 2 of occasional papers for 

1954 on the geology of Michigan: Michigan Geological 

Survey Division Professional Paper 48, 105‐348 p.

Mozola, A. J., 1969, Geology for land and ground‐water 

development in Wayne County, Michigan: Michigan Geo‐

logical Survey Division Report R 3, 25 p.

Nicholas, J. R., Rowe, G. L., and Brannen, J. R., 1996, 

Hydrology, water quality, and effects of drought in Monroe 

County, Michigan: U.S. Geological Survey Water‐Re‐

sources Investigations Report 94‐4161, 169 p.

Nowlin, J., 1973, Water resources of the Clinton Basin, south‐

eastern Michigan: U.S. Geological Survey Hydrologic Atlas 

469, 2 p.

Passero, R., 1983, Information for the evaluation of location 

criteria for sanitary landfills, Kalamazoo County solid waste 

plan: Kalamazoo County Solid Waste Management Plan‐

ning Committee, Tech. rep., 79 p.

Pringle, G. H., 1937, Geology of Arenac County: Michigan 

Geological Survey Division Report P 3, 31 p.

Reeves, H. W., Wright, K. V., and Nicholas, J. R., 2003, 

Hydrogeology and simulation of regional ground‐wa‐

ter‐level declines in Monroe County, Michigan: U.S. 

Geological Survey Water‐Resources Investigations Report 

2003‐4312, 72 p.

Regalbuto, D. P., 1987, An Isotropic Investigation of Ground‐

water in Leelanau County, Michigan: East Lansing, Michi‐

gan, Michigan State University, M.S. Thesis, 54 p.

Rheaume, S. J., 1990, Geohydrology and water quality of 

Kalamazoo County, Michigan, 1986‐88: U.S. Geological 

Survey Water‐Resources Investigations Report 90‐4028, 

102 p.

Riggs, C. H., 1938, Geology of Allegan County: Michigan 

Geological Survey Division, Progress Report 4, 29 p.

Rogers, D. T., Doxtader, S. K., Copeland, C., and Metcalf, 

M., 1996, Evaluation of intrinsic bioremediation of gaso‐

line‐contaminated groundwater in glacial and post‐glacial 

generated sediments: Proceedings of the Tenth National 

Outdoor Action Conference and Exposition; Aquifer Reme‐

diation, Ground Water Modeling, Geophysical Methods, 

vol. 10, p. 323‐337.

Shaffer, B. L., 1969, Palynology of the Michigan “Red Beds”: 

East Lansing, Michigan, Michigan State University, Ph.D. 

dissertation, 250 p.

Simms, C. S., 1988, The aquifers of Barry County, Michigan: 

Michigan Ground Water Survey, Report, 32 p.

Sinclair, W. C., 1959, Reconnaissance of the ground‐water 

resources of Schoolcraft County, MI: Michigan Geological 

Survey Division Report P 22, 84 p.

Sinclair, W. C., 1960, Reconnaissance of the ground‐water 

resources of Delta County, Michigan: Michigan Geological 

Survey Division Report P 24, 93 p.

 References Cited  77
Stark, J. R., Cummings, T. R., and Twenter, F. R., 1983, 

Ground‐water contamination at Wurtsmith Air Force Base, 

Michigan: U.S. Geological Survey Water‐Resources Investi‐

gations Report 83‐4002, 93 p.

Stark, J. R. and McDonald, M. G., 1980, Ground water of coal 

deposits, Bay County, Michigan: U.S. Geological Survey 

Open‐File Report 80‐591, 36 p.

Stewart, D. P., 1948, The surface geology of Wexford County, 

Michigan: East Lansing, Michigan, Michigan State College 

of Agriculture and Applied Science (Michigan State Univer‐

sity), M.S. Thesis, 32 p.

Stone, B. D., ed., , 2001, Surficial Geologic Map of Ber‐

rien County, Michigan: U.S. Geological Survey Open‐File 

Report 01‐0156, 1 sheet, scale 1:100,000, last accessed June 

22, 2005 at http://pubs.usgs.gov/of/2001/ofr‐01‐0156/.

Stramel, G. J., Wisler, C. O., and Laird, L. B., 1954, Water 

resources of the Grand Rapids area, Michigan: U.S. Geo‐

logical Survey Report C 323, 40 p.

Stuart, W. T., 1945, Progress Report of the ground‐water 

resources of the Lansing Area, Michigan: Michigan Geolog‐

ical Survey Division Report P 13, 33 p.

Stuart, W. T. and Stallman, R. W., 1945, Ground water 

resources of the Benton Harbor area, Michigan: Michigan 

Geological Survey Division Report P 12, 15 p.

Stuart, W. T., Theis, C. V., and Stanley, G. M., 1948, 

Ground‐water problems of the Iron River district, Michigan: 

Michigan Geological Survey Division Report T 2, 59 p.

Sugden, D. E. and John, B. S., 1976, Glaciers and landscape: 

A geomorphological approach: London, E. Arnold, Division 

of Hodder and Stoughton Limited, 376 p.

Swanson, D. E., 1970, Ground water in Ionia County, Michi‐

gan: East Lansing, Michigan, Michigan State University, 

M.S. Thesis, 75 p.

Sweat, M. J., 1992, Hydrogeology of Huron County, Michi‐

gan: U.S. Geological Survey Water‐Resources Investiga‐

tions Report 91‐4133, 76 p.

Terwilliger, F. W., 1954, The glacial geology and ground‐wa‐

ter resources of Van Buren County, Michigan: Michigan 

Geological Survey, Occasional papers for 1954 on the geol‐

ogy of Michigan Publication 48, pt. 1, 95 p.

Twenter, F. R., 1975, Ground water and geology, Southeastern 

Michigan water‐resources study: U.S. Geological Survey 

Report M 10, 143 p.

Twenter, F. R., 1981, Geology and hydrology for environmen‐

tal planning in Marquette County, Michigan: U.S. Geologi‐

cal Survey Water‐Resources Investigations Report 80‐90, 

44 p.

Twenter, F. R. and Cummings, T. R., 1985, Quality of ground 

water in Monitor and Williams Townships, Bay County, 

Michigan: U.S. Geological Survey Water‐Resources Investi‐

gations Report 85‐4110, 41 p.

Twenter, F. R., Cummings, T. R., and Grannemann, N. G., 

1985, Ground‐Water Contamination in East Bay Township, 

Michigan: Water Resources Investigations, U.S. Geologi‐

cal Survey Water‐Resources Investigations Report 85‐4064, 

63 p.

Twenter, F. R. and Knutilla, R. L., 1972, Water for a rapidly 

growing urban community ‐ Oakland County, Michigan: 

U.S. Geological Survey Water‐Supply Paper 2000, 150 p.

Twenter, F. R., Knutilla, R. L., and Cummings, T. R., 1975, 

Water Resources of the river basins for minor streams drain‐

ing into the St. Clair River, Lake St. Clair, Detroit River, 

and Lake Erie, southeastern Michigan: U.S. Geological 

Survey Hydrologic Atlas 546, 3 p.

Twenter, F. R., Knutilla, R. L., and Nowlin, J. O., 1976, Water 

resources of Washtenaw County, Michigan: U.S. Geological 

Survey Report M 8, 143 p.

Vanlier, K., 1966, Ground‐water resources of the Battle Creek 

area, Michigan: Michigan Geological Survey Division 

Report W 4, 52 p.

Vanlier, K. E., 1959, Reconnaissance of the ground‐water 

resources of Luce County, Michigan: Michigan Geological 

Survey Division Report P 21, 76 p.

Vanlier, K. E., 1963a, Ground‐water resources of the Alma 

area, Michigan: U.S. Geological Survey Water‐Supply 

Paper 1619‐E.

Vanlier, K. E., 1963b, Reconnaissance of the ground‐water 

resources of Alger County, MI: Michigan Geological Sur‐

vey Division Report W 1, 55 p.

Vanlier, K. E., 1968, Comprehensive planning study of the 

Grand River Basin, Michigan: U.S. Army Corps of Engi‐

neers District Report M 3 (Appendix E), 76 p.

Vanlier, K. E. and Deutsch, M., 1958a, Reconnaissance of the 

ground‐water resources of Chippewa County, Michigan: 

Michigan Geological Survey Division Report P 17, 56 p.

Vanlier, K. E. and Deutsch, M., 1958b, Reconnaissance of the 

ground‐water resources of Mackinac County, Michigan: 

Michigan Geological Survey Division Report P 19, 82 p.

Vanlier, K. E. and Wheeler, M. L., 1968, Ground‐water poten‐

tial of the Saginaw Formation in the Lansing metropolitan 

area, Michigan: U.S. Geological Survey Open‐File Report 

unnumbered.

78  Summary of Hydrogeologic Conditions by County for the State of Michigan
Vanlier, K. E., Wood, W. W., and Brunett, J. O., 1973, 

Water‐supply development and management alternatives for 

Clinton, Eaton, and Ingham County, Michigan: U.S. Geo‐

logical Survey Water‐Supply Paper 1969, 111 p.

Weaver, T., 1996, Hydrogeology and ground‐water quality at 

the Bay Mills Indian Community study area, near Brimley, 

Michigan: U.S. Geological Survey Fact Sheet FS 247‐95.

Western Michigan University, Department of Geology, 1981, 

Hydrogeologic Atlas of Michigan: U.S. Environmental 

Protection Agency Underground Injection Control Program, 

Tech. rep., 35 plates, scale 1:500,000.

Westjohn, D. and Weaver, T., 1998, Hydrologic framework of 

the Michigan Basin regional aquifer system.: U.S. Geologi‐

cal Survey Professional Paper 1418, 47 p.

Westjohn, D. B. and Weaver, T. L., 1996a, Configuration of 

Fresh water/Saline‐Water Interface and Geologic Controls 

on Distribution of Freshwater in a Regional Aquifer System, 

Central Lower Peninsula of Michigan: U.S. Geological Sur‐

vey Water‐Resources Investigations Report 94‐4242, 44 p.

Westjohn, D. B. and Weaver, T. L., 1996b, Hydrogeologic 

Framework of Mississippian Rocks in the Central Lower 

Peninsula of Michigan: U.S. Geological Survey Water‐Re‐

sources Investigations Report 94‐4246, 46 p.

Westjohn, D. B. and Weaver, T. L., 1996c, Hydrogeologic 

Framework of Pennsylvania and Late Mississippian Rocks 

in the Central Lower Peninsula of Michigan: U.S. Geologi‐

cal Survey Water‐Resources Investigations Report 94‐4107, 

44 p.

Westjohn, D. B., Weaver, T. L., and Zacharias, K. F., 1994, 

Hydrogeology of Pleistocene Glacial Deposits and Jurassic 

“Red Beds” in the Central Lower Peninsula of Michigan: 

U.S. Geological Survey Water‐Resources Investigations 

Report 93‐4152, 14 p.

Wiitala, S. W., Newport, T. G., and Skinner, E. L., 1967, Water 

resources in the Marquette Iron Range area, Michigan: U.S. 

Geological Survey Water‐Supply Paper 1842, 141 p.

Wiitala, S. W., Vanlier, K. E., and Krieger, R. A., 1963, Water 

resources of the Flint Area, Michigan: U.S. Geological 

Survey Water‐Supply Paper 1499‐E, 86 p.

Wisler, C. O., Stramel, G. J., and Laird, L. B., 1952, Water 

resources of the Detroit Area: U.S. Geological Survey Cir‐

cular 183, 36 p.

Wood, W. W., 1969, Geochemistry of ground water of the 

Saginaw Formation in the Upper Grand River basin, Michi‐

gan: East Lansing, Michigan, Michigan State University, 

Ph.D. Dissertation, 104 p.

 References Cited  79
Beth A. Apple and Howard W. Reeves —Summary of Hydrogeologic Conditions by County for the State of Michigan—Open-File Report 2007-1236

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