Deglacial History and Paleoenvironments of Northeastern Illinois

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Age (cal yr BP)AMS 14 C datesDepth (cm)DiachronicUnitsWeight percent0 10010,500250peat11,00011,50012,000300350organic matter12,500400marl13,00013,50014,00014,500450500550600Hudson Episodecalcium carbonatesilt loam,laminated15,00015,50016,000650700750800850Keller Farm PhaseLake Michigan SubepisodeWisconsin Episodeterriginous sediment(quartz, feldspar, clay minerals)900Figure 31 Downcore loss-on-ignition data and radiocarbon ages from core BC-1 at the Brewster Creeksite showing the lithologic contact demarcating the terriginous-rich silt of the Wisconsin Episode (MichiganSubepisode) below and the biogenic marl and peat-rich material of the Hudson Episode. From Curryet al. (2007).The results of recent work in northeastern Illinois poses an additional dilemna regarding diachronicclassification. A glacial “phase”, as used by Hansel and Johnson (1996) is the timeassociated with deposition of a material referent (i.e., a lithostratigraphic unit). Radiocarbondating of fossils in ice-walled lake sediment indicates that the latter stages of sedimentation associatedwith stagnating ice may overlap in time with initial formation of an adjacent morainecomposed of another material referent. For example, the sediment comprising ice-walled lakeplains of the DeKalb region date from about 20,400 to 18,600 cal yr BP (17,250 to 15,150 C-14yr BP; Curry, 2008; Stop 7); this time corresponds with the Livingston and Woodstock Phaseswhen the Yorkville and Haeger Members were respectively deposited. The lakes occur beyondthe mapped limits of these units, and the age of their sediments transgresses multiple glacialphases. Hence, they should have their own unique name and referent sections. Since phases40
were not intended to overlap (North American Commission of Stratigraphic Nomenclature, 1983;Hansel and Johnson, 1996), a special case is necessary for ice-walled lake plain deposits. Toavoid a proliferation of new diachronic names, it is proposed that the ice-walled lake deposits inIllinois were deposited during the early Keller Farm phase.Hudson Episode (14,670 cal yr BP – present). The Hudson Episode began when loess-relatedsedimentation ceased after the last glaciation. As discussed above, this time boundary atthe Brewster Creek site coincides with a material change from silt loam to sediment that is dominatedby biogenic marl and peat. At this site, the lake was relatively shallow (< 7 m deep). Thesediment record from deeper lakes (17-20 m deep) in northeastern Illinois (e.g. Crystal Lake inSE McHenry County) are complicated by layers of sandy sediment probably derived from turbiditesthat delivered littoral sediment to profundal zones by deep, wind-driven waves during storms(Curry, unpublished data).The deglacial and postglacial history of northeastern Illinois is known from pollen and ostracoderecords from cores sampled from Nelson and Mastodon lakes (Kane County), Crystal Lake(McHenry County), and Brewster Creek (Curry et al., 2007). A synopsis of the late Pleistoceneand Holocene vegetation history begins with replacement of tundra vegetation by a dense borealforest at about 16,700 cal yr BP (data from Nelson Lake and from Stop 5). This coniferousforest was dense and comprised almost exclusively of white and black spruce, and persisted toabout 14,670 cal yr BP. During the transition from the last glacial to present interglacial (14,670cal yr BP to about 10,700 cal yr BP), deciduous trees became more important, especially blackash. The dominance in the pollen record of this wetland-loving tree and spruce indicates thatnortheastern Illinois remained wet during the transition. At Brewster Creek, spruce pollen persistedto about 10,500 cal yr BP, about 650 years longer than at Crystal Lake (Gonzales andGrimm, unpublished data). The nature of the remainder of the Holocene vegetation record hasbeen investigated in Nelson Lake (Nelson et al., 2006) and in Crystal Lake to about 8,000 cal yrBP (Gonzales, unpublished data). The early Holocene deciduous forest included abundant oak,elm, and black ash, suggesting conditions somewhat wetter than present. Pollen-assemblagesand the δ13C values and accumulation rates of charcoal reveal that the prairie initially developedfrom about 9,000 to 7,300 cal yr BP. There was a brief return to wetter conditions from 7,300 toabout 6,200 cal yr BP after which there was full expansion of the prairie (Nelson et al., 2006).Tree stands were comprised chiefly of oak, hickory, and walnut, and persisted to when the areawas settled by Europeans in the early-mid 1800’s.The modern landscape largely reflects the glacial legacy presented above although the postglaciallandscape has been smoothed somewhat by infilling of depressions and low areas withalluvium and biogenic sediment. Since the encroachment of settlers more than 150 years ago innortheastern Illinois, many trees have been removed, swampy soils have been drained for agriculturaldevelopment, and large amounts of sand and gravel have been extracted for aggregateused in the construction of roads and foundations. Lakes, both natural and man-made, havefilled in quickly with sediment derived from agricultural practices and urban improvements. Asthe population of northeastern Illinois grows, the glacial deposits have found new significanceas both a receptacle for waste disposal and as a groundwater resource, in addition to continueduse in agriculture and as an aggregate resource.41
Page 1 and 2: State of IllinoisRod. R. Blagojevic
Page 3: Deglacial History and Paleoenvironm
Page 6 and 7: AcknowledgementsBrandon is grateful
Page 8 and 9: WINNEBAGOOGLEMarengo MoraineWoodsto
Page 10 and 11: Figure 3 Projected growth areas in
Page 12 and 13: Surficial fine-textured layerTiskil
Page 14 and 15: samples, especially diamict units.
Page 16 and 17: OaOgSuWINNEBAGOOgBOONE MCHENRY LAKE
Page 18 and 19: Bedrock valley floor changes in Kan
Page 20 and 21: illite peak (8.8°2) with thecompou
Page 22 and 23: Grayslake Peat (gr)Peoria Silt (not
Page 24 and 25: DEPOSITS OF THE LAST GLACIATIONMaso
Page 26 and 27: WisconsinCheck here ifH homestead c
Page 28 and 29: Table 1 Summary of particle size of
Page 30 and 31: Table 2 Selected physical propertie
Page 32 and 33: l-h0 counts per second50Diamicton,b
Page 34 and 35: Geochronologicand Chronostratigraph
Page 36 and 37: Wisconsin EpisodeAthens Subepisode
Page 38 and 39: MarengoPhaseMarengo MoraineHarvardS
Page 40: Three erosional channels cut across
Page 43 and 44: Boring WAD-05-02Tinley Moraine*DesP
Page 45: Figure 30 Glacial and lake phases a
Page 49: West Chicago Moraine,9c Higgins/Sut
Page 52 and 53: Benn D.I., 2002, Clast fabric devel
Page 54 and 55: Curry, B.B. 2003. Linking Ostracode
Page 56 and 57: Eyles, N. 1983. Glacial Geology: An
Page 58 and 59: Hajic, E.R., 1990. Late Pleistocene
Page 60 and 61: Johnson, W. H., A. K. Hansel, E. A.
Page 62 and 63: Leighton, M.M., P. MacClintock, L.E
Page 64 and 65: Piskin, K., and R. E. Bergstrom, 19
Page 66 and 67: Vagt, P. J., 1987. Characterization
Page 68 and 69: STOP 1: Buffalo Rock State ParkLarg
Page 70 and 71: ner channel began. Previously, thes
Page 72 and 73: Figure 3 (A) Example of outer erosi
Page 74 and 75: Stop 2a: Wedron Silica Company Quar
Page 76 and 77: N N N0.0W20.5W1W3Depth (m)1.01.5Rin
Page 78 and 79: 0.00.2W3W2W1W1W3W2Ringshearresult0.
Page 80 and 81: to the arrival of the last glaciers
Page 82 and 83: Sedimentology and stratigraphyThe c
Page 84 and 85: prairie-like. Pollen analyses may b
Page 86 and 87: CarboniferousFigure 1 Carboniferous
Page 88 and 89: Figure 3 Largest and best preserved
Page 90 and 91: Figure 6 Small normal faults in lam
Page 92 and 93: and mineralogy, we propose that the
Page 94 and 95: Stop 4: Oswego ChannelThe 15,770 C-
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NewarkMarseillesIroquoisSt. AnneOsw
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Joliet sublobe;retreat to theValpar
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Sediment coresSeveral sediment core
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formed during the late Livingston P
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are being examined by Professor L.
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assistant secretary of the Smithson
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Annotated Illustrated Guide to the
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Figure 4 The BrewsterCreek mastodon
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Figure 6 The left lower 3rd molar o
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Figure 8 The left upper 3rd molar o
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Figure 10 This slide elaborates on
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Aurora Mastodont Project 2004 - A s
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a full skeleton still buried. Ed Mo
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Figure 17 Field leader Anita Weber
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Figure 18 Paleontologist For A Day
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paleontologist/geologist/archeologi
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scientific rationale behind the see
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tures exposed, from well drained in
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N1 km1 miAA’lbgphhwheA1380 lbFelt
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Table 1 Soil horizonation and depth
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Figure 5 Morphological measure of t
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vial upper solum characteristics, d
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material indicates long term disper
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(Table 1). Sand and silt values oft
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STOP 7: DeKalb moundsArchives of de
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acA A ‘*"e H-2278bde(x)1 kmFigure
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1 kmFigure 4 Typical distribution a
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Vertical exaggeration =20x5 mB-9AWe
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Valve concentration(#/gm, moist)0.0
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200-8Value (‰)-6 -4 -2 0 2 0.00 0
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sions encompass the period of final
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Stop 8: Spring Lake Sand and Gravel
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Stratigraphy and Mechanical Stratig
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ABCDEFFigure 3 Characteristic defor
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a.b.C90 mC'WED85 mD'c.D200 mD'NSd.D
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a.b.c.d. e.LHudSTATION E1 E2 E3LHld
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In the weaker units, several charac
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Stop 9: Thelen Sand and Gravel Pits
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Table 1 Lithofacies code for fluvia
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The erosion of the large semi-circu
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Topset sequences are composed of bo
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APPENDIX A. Description of Profile
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pinches out laterally.4 879.6 10.5
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Deglacial History and Paleoenvironments of Northeastern Illinois

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