Post on 07-May-2021
Illinois Preliminary Geologic MapIPGM Lacon-SG
Base map compiled by Illinois State Geological Survey from digital data provided by the United States Geological Survey. Digital Line Graph data from 1994.
North American Datum of 1983 (NAD 83)Projection: Transverse Mercator10,000-foot ticks: Illinois State Plane Coordinate system, west zone (Transverse Mercator)1,000-meter ticks: Universal Transverse Mercator grid system, zone 16
Recommended citation:McKay, E.D., III, R.C. Berg, A.J. Stumpf, and C.P. Weibel, 2007, Surficial geology of Lacon
Quadrangle, Marshall County, Illinois: Illinois State Geological Survey, Illinois Prelimi-nary Geologic Map, IPGM Lacon-SG, 1:24,000.
Geology based on field work by E.D. McKay, R.C. Berg, A.J. Stumpf, and C.P. Weibel, 2001–2003.
This mapping was funded in part by the Illinois Department of Transportation to support planning for upgrade of Illinois Route 29.
Digital cartography by J. Carrell, J. Domier and Z. Golshani, Illinois State Geological Survey.GIS support by P. Johnstone, L. Smith, and B. Stiff, Illinois State Geological Survey.
This Illinois Preliminary Geologic Map (IPGM) is a lightly edited product, subject to less scientific and cartographic review than our Illinois Geological Quadrangle (IGQ) series. It will not necessarily correspond to the format of IGQ series maps, or to those of other IPGM series maps. Whether or when this map will be upgraded depends on the resources and priorities of the ISGS.
The Illinois State Geological Survey, the Illinois Department of Natural Resources, and the State of Illinois make no guarantee, expressed or implied, regarding the correctness of the interpretations presented in this document and accept no liability for the consequences of decisions made by others on the basis of the information presented here. The geologic interpretations are based on data that may vary with respect to accuracy of geographic loca-tion, the type and quantity of data available at each location, and the scientific and technical qualifications of the data sources. Maps or cross sections in this document are not meant to be enlarged.
IPGM Lacon-SG
SURFICIAL GEOLOGY OF LACON QUADRANGLEMARSHALL COUNTY, ILLINOIS
E. Donald McKay III, Richard C. Berg, Andrew J. Stumpf, and C. Pius Weibel2007
1 / °1 2
APPROXIMATE MEANDECLINATION, 2007
MA
GN
ET
IC N
OR
TH
TR
UE
NO
RT
H
ROAD CLASSIFICATION
Primary highway,hard surface
Secondary highway,hard surface
Light-duty road, hard orimproved surface
Unimproved road
State Route
ADJOINING QUADRANGLES1 Whitefield2 Putnam3 Florid4 La Prairie Center5 Henry6 Rome7 Chillicothe8 Washburn
BASE MAP CONTOUR INTERVAL 10 FEET
NATIONAL GEODETIC VERTICAL DATUM OF 1929
For more information contact:Illinois State Geological Survey 615 East Peabody Drive Champaign, Illinois 61820-6964 (217) 244-2414 http://www.isgs.uiuc.edu
1 2 3
4 5
6 7 8
Released by the authority of the State of Illinois: 2007
7000 FEET1000 10000 2000 3000 4000 5000 6000
.5 1 KILOMETER1 0
SCALE 1:24,0001/ 21 0 1 MILE
Illinois Department of Natural ResourcesILLINOIS STATE GEOLOGICAL SURVEY
William W. Shilts, Chief
References
Hansel, A.K., and W.H. Johnson, 1996, Wedron and Mason Groups: Lithostratigraphic reclassification of deposits of the Wisconsin Episode, Lake Michigan Lobe area: Illinois State Geological Survey, Bulletin 104, 116 p.
Willman, H.B., E. Atherton, T.C. Buschbach, C. Collinson, J.C. Frye, M.E. Hopkins, J.A. Lineback, and J.A. Simon, 1975, Handbook of Illinois stratigraphy: Illinois State Geological Survey, Bulletin 95, 261 p.
¹ Stratigraphic nomenclature follows that of Hansel and Johnson (1996) for Wisconsin and younger deposits and Willman et al. (1975) for deposits older than Wisconsin Episode; within each unit, the components are listed in order of decreasing abundance.
² Diamicton is a name for a unsorted or poorly sorted, sedimentary deposit that contains a wide range of particle sizes, such as a till that contains clay, silt, sand, gravel, cobbles and boulders.
&cm
t
h(m)
l-b
h(p)
p/t
c(f)
py
c(fp)
dg
p/l-b
QUATERNARY DEPOSITS
Unit
HUDSON EPISODE (~12,000 years before present (B.P.) to today)
Disturbed ground
Cahokia Formation(floodplain facies)
Cahokia Formation(alluvial fan facies)
Peyton Formation
WISCONSIN EPISODE (~12,000–75,000 years B.P.)
Henry Formation(Parkland facies)
Henry Formation(Mackinaw facies)
Batestown Member,Lemont Formation
buried by >5 feet of Peoria Silt
Tiskilwa Formation
buried by >5 feet of Peoria Silt
PRE-QUATERNARY
Unit
PENNSYLVANIAN PERIOD (~280–315 million years B.P.)
Carbondale and Modesto Formations
Interpretation
Deposits disturbed or modified by human activity in gravel pits, coal mine spoil banks, earthen dams, other excavations, and landfills
Alluvium (river sediment); post-glacial overbank deposits on floodplains, natural levees, and in backwater lakes; coarse deposits in channels, point bars, and tributary streams
Alluvial fan deposits; post-glacial redeposited loess and till in fans where streams and ravines emerge from uplands onto low-slope valley floors; subject to flooding
Slopewash, talus, rock-fall, and slump deposits on or at base of steep slopes in small coalescing fans along bluff of Illinois River valley; post-glacial; may be poorly consolidated and unstable
Sand dunes, dune fields and sheet deposits of sand eroded from underlying outwash and redeposited locally on Illinois River terraces and uplands; proglacial and post-glacial Fluvial (riverine) and ice-marginal outwash deposits in Illinois River valley in terraces, former bars and channels and locally in terraces along tributaries to Illinois River; deposited proglacially by meltwater from distant glaciers; not consistently differentiable from Illinois Episode sand and gravel of the underlying Pearl Formation where intervening tills are absent
Till and associated sediment derived directly from glacial ice; overlain by thin covering of loess; occurs east of the western edge of the Eureka Moraine; absent in the Illinois River valley and tributary valleys, where removed by post-glacial erosion
Till and associated sediment derived directly from glacial ice; exposed in gullies, excavations and along steep slopes where overlying Peoria Silt and the Batestown Member have been eroded; occurs throughout the uplands of the area; absent in the Illinois River valley and tributary valleys, where removed by post-glacial erosion; where lower part of the unit is gray, the Delavan Member can be differentiated, and where it contains common wood fragments, the Oakland Member can be differentiated.
Interpretation
Lithified marine, estuarine, deltaic, fluvial and swamp deposits
Description1
Areas of disturbed earth and/or removed earth; grain size ranges from clay to gravel, and may include waste or other rubble
Silt and clay with local surface occurrences of sand and gravel; typically grades at depth to sand or sand and gravel, which may be indistinguishable from Henry Formation; stratified, brownish gray to gray; 5 to 50 feet thick
Silt and silty clay, interbedded with fine sand, and locally gravel and redeposited bedrock clasts; brownish soft to moderately stiff gray; calcareous or non-calcareous; typically overlies Cahokia or Henry Formations; interfingers with Cahokia floodplain facies; 5 to 30 feet thick
Silt, clay, sand, gravel and diamicton; unstratified to crudely stratified; yellowish brown to brownish gray; may include bedrock clasts; overlies Cahokia, Henry, or older glacial drift or bedrock; interfingers with Cahokia; 5 to 25 feet thick
Sand; very fine to fine, well-sorted, and loose; yellowish brown to grayish brown; calcareous in lower part; conformably overlies Henry Formation; 5 to 15 feet thick
Sand and gravel with cobbles and boulders; stratified; yellowish brown to grayish brown; calcareous; usually clean and moderately well sorted; unconformably overlies older sand and gravel deposits, glacial diamictons², or bedrock; 10 to 20 feet thick in tributary valleys and 10 to 80 feet thick in Illinois River valley
Pebbly silty clay loam diamicton; unstratified; olive (oxidized) to grayish brown (unoxidized); firm to hard; compact; calcareous; massive to jointed; some cobbles, few boulders; discontinuous beds of sand, gravel, silt, or clay; overlain in places by wind-blown silt (loess) of the Peoria silt; unconformably overlies Tiskilwa Formation or older units; 5 to 35 feet thick
Pebbly loam diamicton; unstratified, reddish brown (oxidized) to dark brownish gray with distinctive reddish cast (unoxidized); firm to hard, calcareous; some cobbles; few boulders; includes discontinuous beds of stratified sand, silt, or clay; lower 5 to 30 feet commonly more silty than upper part, usually lacks reddish cast, and may contain dispersed wood fragments and gastropod shells; unconformably overlies Ashmore Tongue (sand and gravel), Morton Tongue (silt), Roxana Silt, or older deposits; 25 to 120 feet thick
Description
Shale, clay, sandstone, limestone, coal
$T
"e
"e
"e
"e
"e
"kSG 20370
Outcrop
Stratigraphic boring
Water boring
Engineering boring
Coal boring
Hand-auger boring
Labels indicate samples (S) or geophysical log (G). Numeric labels indicate the county number. Some county numbers are not shown in areas of closely spaced boreholes.Outcrop and hand-auger boring labels indicate geologist’s field number. Dot indicates boring is to bedrock.
Contact
Crest of the Eureka Moraine
Data Type
Note: The county number is a portion of the 12-digit API number on file at the ISGS Geological Records Unit. Online well and boring records are available from the ISGS Web site.
! ! ! ! ! ! ! ! ! ! ! !
460
700
650
550
470
500
650
650
670
670
650
680
500
700
700
630
550
600
600
670
680
500
650
630
650
550
650
650
550
650
700
650
550
450
700
550
650
450
680
680
500
650
600
650
640
650
650
700
450
500
700
600
680
500
450
450
650
550
600
670
650
650
500
550
500
650
500
500
500
700
500
700
500
650
500
550550
650
650
500
600
650
650
650
650
680
650
460
550
500
700
450
650
550
700
650
600
700
700
700
450
650
650
450
500
500
700
650
450
650
550
670
670
650
650
600
650
650
650
650
500
650
490
480
650
550
450
500
650
500
680
680
640
690
640
670
530
500
650
650
500
680
450
470
650
500
550
650
450
550
650
680
450
600
500
500
550
600
600
650
700
9
43
21
8
5
1 6
1816
10
15
2528
13
23
14
24
16
26
33
15
21
27
7
22
35 3634
30
21
36
22
19
25
11
14
2
23
18
31
19
30
7
24
9
17
17
32
29
20
20 20
17
31
12
88
35
1211
10
6
29
13
13
26
272829 26
24
23
6
29
17
17
29
29
26
26
17
T. 30 N.
T. 29 N.
R. 3 W. R. 2 W.
T. 30 N.
T. 29 N.
T. 13 N.
R. 9 E.
R. 9 E.
T. 12 N.
T. 13 N.
T. 13 N.
T. 12 N.
R. 3
W.
R. 2
W.
R. 10 E.
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
!!
Eu
r ek a
Mo r a i n e
"e
"k
"k
"k
"k
"k
"k
"k
"k
"e
"k
"k
"e
"e"e
"e
"k"k
"k"k"k
"k
"k
"k
"k
"e"k
"k
"k
"e
"k
"k
"e
"k
"k
"k
"e
"k
"k
"e
"e
"e
"k
"e
"k
"k
"k
"k
"k
"e
"e
"e
"k
"k
"k"k
"k"k"k
"k
"k
"k
"e
"e
"k
"k
"k
"e
#*S
$T
$0
#*S
$T
$0
$T
#*S
$0
$0$T
$T$T
$0
$0
$T #*S #*
S #*S
$T$0
$0
$0
$0
$0
$0
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e
"e "e
"e
"e
"e
"e
"e
"e
"e"e
"e"e
"e"e
"e"e
"e
"e
"e"e
"e
"e"e"e
"e
"e"e"e"e
"e"e"e
"e
"e
"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e
"e"e"e"e"e"e
"e
"e
"e
"e"e"e"e"e"e"e"e"e"e"e"e
"e
"e
"e
"e
"e
"e
"e
"e
"kS
"kS
"kS
"eS
"eS
"k
$T
"kSG
"kSG
"kSG
"e
"e
"e
"e
"k
"k
"k
"k
"k
"k
"e
"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e
"e
"e"e"e"e"e
"e"e"e"e"e"e"e"e"e"e"e"e
"e
"e
21010
21009
21008
20415
20230
20731
00166
00130
00040
23454
20699
20219
00167
00098
20841
20840
20839
20838
2083720836
20835
20834
20833
20832
20831
20824
20823
20822
20820
20819
20758
20349
00170
00021
20737
20230
20696
20772
20770
20765
20502
20732
20332
20507
20697
00003
00002
20223
00096
20331
00161
00160
00001
20357
20434
20659
20287
20744
20694
20337
20534
00109
20728
20363
2034500085
20746
20348
20347
20753
20372
20286
20661
20451
20407
00156
20370
00137
20432
20369
20665
20364
00022
20327
20222
20239
20793
20787
20817
20816
2050620505
20504
20503
20762
2037120394
20406
20601
539538
537
536535
534
518
580
581
517
325324
311
310
307
306
299
298
286
575
282
276
1031
577
579
578
571
572
574
570
569
568
00043
20922
20955
20951
20947
20945
20999
20885
20985
20905
20949
20998
20888
20978
2088220964
20879
20982
20983
20849
20815
20814
00037
00097
00044
20943
20934
21000
20911
20974
20977
20918
20987
20876
20826
20782
20925
20941
20971
20912
20914
20916
20906
2091920990
20989
20877
20875
20798
20846 20843
20830
20829
20828
20827
20825
20781
c(fp)
c(fp)
c(fp)
c(fp)
c(fp)
p/l-b
p/l-b
h(m)
h(m)
p/l-b
p/l-b
t
t
t
t
t
t
t
t
&cm
c(f)
h(m)
c(f)
l-b
l-b
t
t
t
t
t
t
t
t
l-b
l-b
p/l-b
l-b
h(m)
h(m)
t
t
t
t
t
t
h(m)
t
t
l-b
c(f)
h(m)
t
tt
l-b
t
t
p/l-b
c(fp)
c(fp)
l-b
t
t
l-b
t
t
py
p/l-b
t
h(m)
t
h(p)
t
p/t
p/l-b
t
p/t
t
t
p/l-b
t
&cm
p/t
t
t
c(fp)
t
l-b
l-b
l-b
t
t
l-b
p/t
t
t
t
t
t
c(fp)
c(fp)
h(m)
p/l-b
dg/h
p/l-b
t
h(p)
l-b
t
c(fp)
t
t
l-b
c(fp)
dg/h
t
p/l-b
l-b
h(p)
l-b
t
l-b l-b
h(m)
l-b
c(fp)
c(fp)
l-b
l-b
l-b
p/t
dg/h
p/t
t
t
p/l-b
t
py
t
l-b
dg/h
t
t
py
t
l-b
p/t
t
h(p)
h(p)
p/t
l-b
l-b
l-b
l-b
t
t
h(p)
p/t
h(m)
l-b
l-b
l-b
l-b
l-b
l-b
p/t
h(m)
l-b
py
p/t
t
l-b
l-b
h(p)
t
l-b
h(m)
p/t
l-b
p/t
l-b
l-b
l-b
l-b
h(p)
tt
l-b
l-b
p/l-b
t
l-b
p/l-b
p/t
l-b
l-b
l-b
l-b
l-b
l-b
l-b
l-b
t
l-b
h(m)
t
p/t
h(m)
h(m)
p/l-b
h(m)
p/t
p/t
p/l-b
h(m)
dg/hdg/h
p/t
p/t
t
dg
l-b
c(fp)
t
&cm
&cm
&cm
c(f)
&cm
&cm
h(p)
&cm
&cm
&cm
l-b
h(p)
p/l-b
h(p)
t
l-b
p/l-b
p/l-b
p/l-b
c(f)
l-b
l-b
l-bl-b
c(fp)
c(fp)
h(m)
t
l-b
l-b
l-b
l-b
l-b
l-bl-b
l-b
l-b
l-b
t
l-b
c(fp) h(p)
&cm
&cm
l-b
l-b
h(p)
l-b
p/l-b
c(fp)
l-b
p/l-b
h(p)
l-b
l-b
l-b
p/t
l-b
p/t
l-b
c(fp)c(fp)
t
c(fp)
h(p)
p/t
h(p)
l-b
h(p)
p/l-b
c(fp)
p/t
c(fp)
l-b
p/t
p/t
h(p)
c(fp)
p/t
l-b
t
p/t
h(p)
p/l-b
h(p)
p/t
h(m)
l-b
p/l-b
l-b
l-b
p/t
l-b
p/t
l-b
p/l-b
p/t
h(m)
h(m) h(m)
h(m)
p/t
l-b p/t
p/t
p/l-b
h(p)
l-b
p/t
l-b
h(m)
h(m)
c(fp)
t
l-b
h(m)
l-b
l-b
h(p)
p/t
l-b
p/t
t
p/t
p/t
l-b
l-b
l-b
l-b
c(fp)
c(fp)
l-b
p/t
p/t
l-b
l-b
h(p)
p/l-b
p/l-b
t
t
p/t
t
l-b
p/t
p/t
p/t
dg/h
l-b
&cm
t
t
p/l-b
l-b
&cm
c(fp)
&cm
c(fp)
t
l-b
l-b
TN/B
p/l-b
t
t