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(/169

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"!175"!144

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Gowrie

Dayton

Stratford

Jewell

Williams

Webster City

Fort Dodge

Lehigh

Duncombe

Little Wall Lake

GooseLake

BadgerLake

R30W R29W R28W R27W

R26WR25W R24W R23W

R23WR24WR25WR26WR27WR28WR29WR30W

T89N

T88NT87N

T86N

T86N

T87N

T88N

T89N

T90N

T90N

Deer Creek Badge r Cre

ek

Soldier Cree

k

Brus hy Creek

Brush y Creek

South Branch Lizard Creek

Lizard Cr e ek

Spr ing Creek

Hardin Cre

ek

Wes

t Bra

nch Buttri

ck C

reek

East

Branch B

uttrick C r

Skillet Creek

Bre wers Cr eek

Boo ne River

Eagle Creek

Boone Riv

er

Buc

k C

reek

Boon e R

iver

Whi

te F

ox

Cre

ek

Squaw C

reek

Keigley Brook

South Skunk River

Sout h Skunk River

South Fork I o wa River

Tipton Creek

Long Dick Creek

Bear

Cre

ek

.-,35

.-,35

Des Moines River

WEBSTER

HAMILTON

Brushy CreekLake

2 0 2 4 6 8 10 Miles

2 0 2 4 6 8 10 Kilometers

1:100,000

Surficial Geology of the Des Moines Lobe of IowaHamilton and Webster Counties

LEGEND

Description of Mapping Un its

Hudson Episode

Qo - M uck and Peat (DeForest Formation-W oden Mbr) Generally 2.5 to 11 m of black to very dark gray, calcareous, muck, peat andsilty c lay loam colluvium and organic sediments in drained and undrained closed and semi-closed depressions. Overlies a gray,calcareous, massive, dense loam diamicton (Dows Fm.- Alden Mbr.) or may overlie Noah Creek Fm. sand and gravel. Low relieffeatures that occupy depressions and low sags on the landscape. Seasonal high water table.

Qal - Alluvium (DeForest Formation-Undifferentiated) Variable thickness of less than 1 m to 5 m of a very dark gray to brown,noncalcareous, stratified silty c lay loam, clay loam, loam to sandy loam alluvium and colluvium in stream valleys, hillslopes andclosed depressions. May overlie Dows Formation (Morgan or Alden Mbr.), Noah Creek Formation or Pennsylvanian/Mississ ippianbedrock. Occupies low relief modern floodplain, c losed depressions, modern drainageways or toeslope positions on the landscape.Seasonal high water table

Qe - Eolian Sand (Peoria Formation--sand facies) Generally less than 3 m of yellowish brown, massive, calcareous loamy sand tofine sand. It may o verlie yellowish-brown coarse-grained sand and gravel (Noah Creek Fm.) or it may overlie yellowish to grayishbrown usually calcareous, stratified loam to silt loam to sandy loam diamicton; textures can be quite variable (Dows Fm.-MorganMbr.). Usually restric ted to a narrow belt on major river valley bottoms or adjacent uplands on the Des Moines Lobe.

Late Wisconsin Episode

Qtp - Till Plain (Dows Formation-Morgan Mbr.) Less than 8 m of yellowish brown, often calcareous and fractured, stratified loamto silt loam to sandy loam diamicton; textures can be quite variable. Overlies gray, calcareous , massive, dense loam diamicton (DowsFm.-- Alden Mbr.). Low to moderate re lief, (3 m to 8 m), undulating plains with irregular surface patterns. Seasonal high water table.

Qtpl - Till Plain with lineated ridge forms (Dows Formation-Morgan Mbr.) Less than 3 m of yellowish to grayish brown, oftencalcareous and fractured, stratified loam to silt loam to sandy loam diamicton; textures can be quite variable . Overlies gray,calcareous, massive, dense loam diamicton (Dows Fm.- Alden Mbr.). Low relief, (less than 3 m of local relief), s lightly undulatingplains with irregular surface patterns. Lineated ridge forms (Dows Formation-Morgan Mbr./ Pilot Knob Mbr.) Less than 6 m ofyellowish brown, often calcareous, s tratified loam to silt loam to sandy loam diamicton; textures can be quite variable . Occasionally,these ridges consist primarily of sand and gravel and exhibit evidence of syndepositional collapse (Pilot Knob Mbr.) Overlies gray,calcareous, massive, dense loam diamicton (Dows Fm.-Alden Mbr.). Faint to well-defined lineated ridges oriented transverse toglacier flow are inset on till plain. Ridges are moderate to high relief features (3 to 8+ m). Overall landform is a swell and swaletopography. Seasonal high water table .

Qtr - Till Ridge (Dows Formation-Morgan Mbr.) Generally 4 to 15 m of yellowish to grayish brown, usually calcareous andfractured, stratified loam to silt loam to sandy loam diamicton; textures can be quite variable. Overlies gray, calcareous, massive,dense loam diamicton (Dows Fm.-- Alden Mbr.). Moderate to high relief hummocky landform feature exceeds 3-8 m of local relief.

Qoch - Outwash Channels (Noah Creek Formation) Generally less than 7 m of yellowish brown coarse-grained sand and gravel.Overlies gray, calcareous, massive, dense loam diamicton (Dows Fm.-- Alden Mbr.). In valley pos itions, it is at the land surface ofolder terraces. On the modern floodplain it is buried by DeForest Fm. alluvium. Low-relief landforms that may be depos ited in broadterraces; long, narrow longitudinal terraces or in cuspate-shaped point terraces.

Qochb - Outw ash Channels shallow to bedrock (Noah Creek Formation) Generally less than 5 m of yellowish brown coarse-grained sand and gravel. In the northern part of Webs ter county the unit overlies Mississippian carbonate bedrock. From Fort Dodgesouth the unit overlies Pennsylvanian bedrock. In valley positions, the unit is at the land surface of older terraces. On the modernfloodplain it is buried by DeForest Fm. alluvium. Low-relief landforms that may be deposited in long, narrow longitudinal terraces orin cuspate-shaped point terraces which overlie bedrock.

Qof - Outwash Fan (Noah Creek Formation) Thickness can be quite variable from 3 to 12 m of yellowish-brown coarse-grainedsand and gravel. May overlie yellowish to grayish brown usually calcareous, stratified loam to silt loam to sandy loam diamicton;textures can be quite variable (Dows Fm.-Morgan Mbr.) or it may overlie a gray, calcareous, massive, dense loam diamicton (DowsFm.- Alden Mbr.). Narrow low-relief apron that gently slopes away from the moraine front. Seasonal high water table.

Qglp - Lake Sediment Plain - broad-scale landform features (Dows Formation-Lake Mills Mbr.) Generally less than 3 m of darkgrayish brown, massive, calcareous s ilty c lay loam, silt loam overlying a thin basal increment of sand and gravel (<1 m). It mayoverlie yellowish to grayish brown usually calcareous, stratified loam to silt loam to sandy loam diamicton; textures can be quitevariable (Dows Fm.--Morgan Mbr.) or it may overlie a gray, calcareous, massive, dense loam diamicton (Dows Fm.-- Alden Mbr.).Low relief broad plain with less than 3 m of local relief. Seasonal high water table .

Qglhc - Collapsed Lake Sediments - hummocky isolated ice-walled lake plains-flat-topped hummocks (Dows Formation-LakeMills Mbr./ Morgan Mbr.) Generally less than 3 m of dark grayish brown, massive, calcareous s ilty clay loam, silt loam overlying athin basal increment of sand and gravel (<1 m). It usually overlies yellowish to grayish brown usually calcareous, stratified loam tosilt loam to sandy loam diamicton; textures can be quite variable (Dows Fm.--Morgan Mbr. Isolated ice-walled lake plains comprise aportion of this landform area. Other hummocks consist of less than 4 m of yellowish to grayish brown usually calcareous, s tratifiedloam to s ilt loam to sandy loam diamicton (Dows Fm.--Morgan Mbr.). Overlies a gray, calcareous, massive, dense loam diamicton(Dows Fm.-- Alden Mbr.). Moderate to high relief hummocky landform area with 3 to 8+ m of local relief.

Qlglp - Lake Sediment Plain - broad-scale landform features with lineated ridge forms (Dows Formation- Lake MillsMbr.)/Morgan Mbr.) Generally less than 3 m of dark grayish brown, massive, calcareous silty clay loam, silt loam overlying a thinbasal increment of sand and gravel (<1 m). It may overlie yellowish to grayish brown usually calcareous, stratified loam to silt loamto sandy loam diamicton; textures can be quite variable (Dows Fm.--Morgan Mbr.) or it may overlie a gray, calcareous , massive,dense loam diamicton (Dows Fm.-- Alden Mbr.). Low relief broad plain with less than 3 m of local re lief. Faint lineated ridgesoriented transverse to glacier flow are inset on till plain adjacent to major stream and river valleys. Ridges are lower relief features(<3 m). Overall landform is an undulating plain. Lo w relief (<3 m) on lineated ridges. Seasonal high water table.

Complexes

Qsgc - Supraglacial Complex (Dows Formation-P ilot Knob Mbr./ Morgan Mbr.) Greater than 3 m and less than 15 m of yellowishbrown, often calcareous and fractured, s tratified sand and gravel with interbedded stratified loam diamicton. Collapse features areusually evident. In depressions and sags on upland surfaces, the sand and gravel may be buried by DeForest Fm.-Woden Mbr.Overlies gray, calcareous, massive, dense loam diamicton (Dows Fm.-- Alden Mbr.). Moderate to high relief (3 to 8+ m) hummocks,beaded ridges, kames and associated linked drainages on upland surfaces.

Qsgclp - Supraglacial Complex with lineated ridge forms (Dows Formation-Pilot Knob Mbr./ Morgan Mbr.) Greater than 4 m andless than 10 m of yellowish brown, often calcareous and fractured, s tratified sand and gravel with interbedded stratified loamdiamicton or yellowish to grayish brown, often calcareous and fractured, s tratified loam to silt loam to sandy loam diamicton; texturescan be quite variable. In depressions and sags on upland surfaces, the sand and gravel may be buried by DeForest Fm.-Woden Mbr.Overlies gray, calcareous, massive, dense loam diamicton (Dows Fm.-- Alden Mbr.). Faint to well-defined lineated ridges orientedtransverse to glacier flow are inset on till plain. Ridges are moderate to high relief features (3 to 8+ m). Occasionally, these ridgesconsist primarily of sand and gravel and exhibit evidence of syndepositional collapse (Pilot Knob Mbr.). Overall landform can behummocky or swell and swale topography. Moderate to high relief (3 to 8+ m) on lineated ridges and hummocks. Seasonal high watertable.

Pu/Mu - Pennsylvanian Bedrock(Cherokee Group)/Mississippian Bedrock (St. Louis and Pella Formations) Pennsylvanian--P rimarily composed of deltaic sediments associated with the Cherokee Group. Lithologies are extremely variable. Major lithologiesconsist of shale and sandstone with minor coal seams. Mississ ippian-- Composed of marine limestones, s andstones and shales.Outcrops present along the Des Moines River valley north of Fort Dodge. In the Fort Dodge vicinity some outcrops of Jurassic agegypsum and red mudstones are present.

Qpq - Pi ts and Quarries Gypsum and limestone quarries; and sand, gravel, and clay pits . Extent mapped as shown in county soilsurveys.

Qf - Fill Areas of major land filling. Fill associated with railroad grades, highway grades and land leveling. Variable in textureranging from loamy to sandy to concrete rubble . Extent mapped as shown in county soil surveys.

Water Features

Drill Hole Locations#

SURFICIAL GEOLOGIC M APOF THE DES M OINES LOBE OF IOWA

Hamilton and Webster Counties

Geological Survey BureauOpen File Map 2000-1

M ay 2000

Prepared by

Deborah J. Quade1

James D. Giglierano1

E. Arthur Bettis2

Robin J. Wisner3

Supported by the U.S. Geological SuveyCooperative Agreement Number 99HQAG0064

National Cooperative Geologic Mapping Program (STATEMAP)

Energy and Geological Resources DivisionGeological Survey Bureau

Iowa Department of Natural ResourcesLyle W. Asell, Interim Director

ACKNOWLEDGEMENTS

Recognized for direct contributions to map’s production: Timothy J. Kemmis, Adrian Goetemoeller, Andy Asell, Kathryn Benz, Mary Ellis,Courtney Nash, Leah Young, Jessica Overmohle, Shane Smith, Julia E. Tabbut, Stephanie Tassier-Surine, Mark Alexander, Matthew A. Culp,Robert M. McKay, Rick Langel, Billy J. Bunker, Jackson L. Gilmore, Calvin F. Wolter, Bernard E. Hoyer, Pat J. Lohman, Michael J. Bounk,Donald L. Koch and Mary P. Skopec. Drilling was provided under contract by Aquadrill. Assistance in obtaining permission from landownerswas provided by the Natural Resources Conservation Service, Fort Dodge Office. A special thanks to the following individuals who graciouslyallowed access to their land for drilling: Robert Condon, Terry Condon, Edna Schultz, Delmar Estlund, Delbert Dencklau, Ralph Sonnicksen,Don Shelton, William Petersen, Vern Chalstrom, Margaret Banwell, Russ Slotten, Garret Geisler, Engstrom, Schwendemann, Greg Carlson, DonWill, Steve Satre, John Andersen, Anne Kaputska, Ray Allard, Webster County Conservation Board and the Fort Dodge Asphalt Co., WebsterCounty; George Myers, Darrel Hay, Jim Walker, Lyle Anderson. Dennis Doolittle, John VanLangen, Leslie Eggers, Barbara Sylvester, LawrenceVanHauen, Bob Sharer, Brian Wilcox, Don Hill, Bruce Berggren, Meryln Hegland, Kevin Larsen, Glen Hodnefield, Lon Crosby and theHamilton County Conservation Board, Hamilton County.

1Iowa Department of Natural Resources, Geological Survey Bureau,109 Trowbridge Hall, Iowa City, IA 52242-13192 Department of Geoscience, The University of Iowa, 121 Trowbridge Hall, Iowa City, IA 522423 Natural Resources Conservation Service, 1617 N. Lake St., Storm Lake, IA 50588

LYONOSCEOLA

SIOUXOBRIEN CLAY

PALO ALTO

DICKINSONKOSSUTHEMMET

POCAHONTAS

PLYMOUTH

BUENA VISTACHEROKEE

HUMBOLDT

WOODBURY

IDA SAC

WEBSTER

WINNEBAGO

CERRO GORDO

WRIGHT FRANKLINBUTLER BREMER

HAMILTON HARDIN GRUNDY

BLACK HAWK

MITCHELL HOWARDWORTH

HANCOCK

FLOYD CHICKASAW

WINNESHIEKALLAMAKEE

FAYETTE CLAYTON

BUCHANAN DELAWARE DUBUQUE

CRAWFORDCARROLL GREENE BOONE STORY

HARRISONSHELBY

CALHOUN

POLKDALLASGUTHRIEAUDUBON

POTTAWATTAMIE CASSADAIR MADISON WARREN

MILLS ADAMSUNION CLARKE

FREMONT PAGE

DECATURTAYLOR

RINGGOLD

MONTGOMERY

MARSHALL

JASPER POWESHIEK IOWA

TAMA BENTON LINN

MARION MAHASKA KEOKUK WASHINGTON

JACKSON

CEDAR

CLINTON

SCOTT

MUSCATINE

JONES

LOUISA

JOHNSON

LUCAS MONROE WAPELLO JEFFERSON HENRY

DES MOINES

LEE

VAN BURENDAVISAPPANOOSEWAYNE

MONONA

Mapped area shown in yellow

Des Moines LobeRegion

K:\DmLobe2\Finalmap\Final.apr August 3, 2000