Lithostratigraphy: Wedron Group >>Lemont Formation >>Haeger Member
Chronostratigraphy: Cenozoic Erathem >>Quaternary System >>Pleistocene Series
Ardith K. Hansel and W. Hilton Johnson
Haeger Till Member (Willman and Frye 1970).
Haegers Bend, a village along the Fox River in McHenry County.
The Haeger Till Member of the Wedron Formation was originally defined by Willman and Frye (1970) and described as a silty, sandy, gravelly till interstratified with sand and gravel outwash. It was mapped as a surface unit in the Harvard Sublobe area. Although they defined the upper boundary of the Haeger Till Member as the contact with the Wadsworth Till Member (fig. 7), Willman and Frye (1970) expressed some uncertainty as to whether sandy Haeger till graded southward into clayey Wadsworth till along the West Chicago Moraine or, instead, was overlapped by Wadsworth till (fig. 13). The latter interpretation was accepted by Johnson et al. (1985b) and Kempton et al. (1987b), who recognized the Haeger Till Member in the subsurface beneath the Wadsworth Till Member east and south in Lake and Cook Counties. Johnson et al. (1985b), Hansel and Johnson (1986, 1987), and Johnson and Hansel (1989) correlated the Haeger Member with the Lemont drift (Bretz 1939, 1955), which crops out along the Des Plaines Channel southwest of Chicago. In the Joliet Sublobe area where the Wadsworth Till Member is the surface drift, Johnson et al. (1985b) and Hansel and Johnson (1987) concluded the West Chicago Moraine is a superposed feature that reflects in part a buried moraine that formed at the Haeger-Lemont ice margin. In that area, the moraine contains Haeger-Lemont drift overlain by Wadsworth diamicton and represents two distinct glacial events. Hansel et al. (1985a) proposed a new name, Woodstock Moraine, be used for the part of the moraine that represents the Haeger ice-margin position in the area of the Harvard Sublobe (fig. 13). They suggested the name West Chicago Moraine be applied for only that part of the moraine in the Joliet Sublobe area where the Wadsworth Till Member is at the surface.
The Haeger Till Member of the Wedron Formation (Willman and Frye 1970) is herein classified as the Haeger Member of the Lemont Formation. The Haeger Member consists of a sandy loam diamicton unit that often contains lenses and beds of sorted sediment in its upper part. Typically, it is underlain by a coarsening-upward stratified facies that sometimes contains beds and tongues of diamicton near the top (see for example, Fraser and Cobb 1982, Johnson et al. 1985b, Hansel and Johnson 1986, Johnson and Hansel 1989, and Schneider 1983). In this report, the coarsening-upward sand and gravel is classified as the Beverly Tongue of the Henry Formation, and it is locally underlain by a tongue of the Equality Formation (Fraser and Cobb 1982). In McHenry County, the diamicton facies (Haeger Member) is often missing, probably due to subsequent erosion, and the Henry Formation is the surficial unit.
Roadcuts along the Algonquin-Cary Road, 0.5 mile (0.8 km) northwest of Haegers Bend; no longer exposed.
Beverly Sand and Gravel Pit Section (fig. 19); good for lithology and lower contact with the Beverly Tongue of the Henry Formation (contact with underlying Yorkville Member confirmed from dredging in base of pit).
The Haeger Member is the coarse grained, uppermost unit of diamicton in the Lemont Formation. The Haeger Member diamicton consists of gravelly, sandy loam that is typically oxidized to yellow brown in surface exposures, but it is light gray to gray in the subsurface. The Haeger Member is commonly underlain by a proglacial, coarsening-upward sand and gravel sequence (Fraser and Cobb 1982), which is classified herein as the Beverly Tongue of the Henry Formation (fig. 19). In the Joliet Sublobe area, the Haeger Member is overlain by the Wadsworth Formation.
Haeger diamicton in McHenry County is generally readily distinguishable because it is distinctly coarser grained than other units of the Wedron Group and it is oxidized to yellow brown. It is most similar to diamicton of the undivided Lemont Formation, although it is sandier and less illitic than type-Lemont diamicton southwest of Chicago. A lateral change in texture and clay-mineral composition appears to occur between the type areas of the two units (Johnson et al. 1985b, Johnson and Hansel 1989). Locally, diamicton of the Tiskilwa Formation and that of the lower part of the Haeger Member may be similar as a result of entrainment of red Tiskilwa diamicton during the Haeger advance. Schneider (1983) noted that locally the Haeger-equivalent New Berlin till is redder in its lower part in southeastern Wisconsin.
Extent and thickness
The Haeger Member forms a wedge-shaped deposit that overlaps the Beverly Tongue, the Yorkville Member, or the Tiskilwa Formation and pinches out to the north and east beneath the Wadsworth Formation. The surface extent of the Haeger Member is limited to the Harvard Sublobe area; it is the surface diamicton over about half of McHenry County and very minor parts of adjacent Lake, Kane, and Cook Counties (fig. 13). In Wisconsin, the equivalent New Berlin Member of the Holy Hill Formation is mapped at the surface in the Delavan Sublobe area (Schneider 1983, Mickelson and Syverson, in press; fig. 11). Geophysical evidence for a gravelly diamicton underlying the Wadsworth Formation beneath southwestern Lake Michigan was recognized by Welkie and Meyer (1983) and Foster and Colman (1991), and correlation of this gravelly diamicton with the Haeger Member was suggested. The Haeger Member is generally less than 10 meters (33 ft) thick and thins to less than 1 meter (3.3 ft) in parts of northeastern Illinois and southeastern Wisconsin (Fricke and Johnson 1983).
The Haeger Member of the Lemont Formation consists of calcareous, light gray to gray, coarse textured (sandy loam) gravelly diamicton that contains lenses of sand, gravel, silt, and clay. The Beverly Tongue of the Henry Formation, which consists of a coarsening-upward succession of stratified sediment that is similar in lithology to Haeger diamicton, is common beneath the diamicton unit. Typically, the Haeger Member is oxidized to yellow brown. Paleozoic dolomite is the dominant clast lithology.
Lower boundary: the contact with the Yorkville Member of the Lemont Formation, the Tiskilwa Formation, the Beverly Tongue of the Henry Formation (fig. 19), or older units. Upper boundary: the contact with the Wadsworth Formation, upper tongues of the Peoria Silt and the Henry and Equality Formations, or postglacial units.
Age and correlation
The Haeger Member was deposited during the Woodstock Phase of the Michigan Subepisode, probably between about 16,200 and 15,500 radiocarbon years ago (Hansel and Johnson 1992; fig. 10). It correlates with the New Berlin Member of the Holy Hill Formation of Wisconsin and possibly the Ganges till of Michigan (fig. 11).
Environments of deposition
The Haeger Member is interpreted to be the subglacial and ice-marginal facies of a classic glacigenic sequence; it is predominantly till and reworked supraglacial and ice-marginal sediment. Where complete, the full sequence consists of proglacial lacustrine and/or fluvial sediment (a coarsening-upward sequence of silt, sand, and gravel) interbedded with deposits of ice-marginal debris flows near the top and overlain by till, supraglacial redeposited sediment, and proglacial fluvial and lacustrine deposits. The hummocky topography of the Woodstock and Valparaiso Moraines suggests thickened debris-rich ice accumulated in the supraglacial position. This occurrence was probably the result of compressive flow and overriding of slow-moving or stagnant ice, dammed by older drift and the bedrock divide. This action produced a predominance of ice-marginal sedimentation as the Lemont-Haeger-New Berlin ice melted (Hansel and Johnson 1987). Clast and matrix lithologies are consistent with a fairly local source for much of the unit (i. e., the Paleozoic bedrock along the western flanks of the Lake Michigan basin and older Quaternary units in southeastern Wisconsin and northeastern Illinois), although crystalline erratics are not uncommon.
Reclassified unit. Name changed to the Haeger Member and unit classified as part of the Lemont Formation. Formerly classified as the Haeger Till Member of the Wedron Formation.
BRETZ, J. H., 1939, Geology of the Chicago Region, Part I- General: Illinois State Geological Survey Bulletin 65, 118 p.
BRETZ, J. H., 1955, Geology of the Chicago Region, Part II— The Pleistocene: Illinois State Geological Survey Bulletin 65, 132 p.
FOSTER, D. S., and S. M. COLMAN, 1991, Preliminary Interpretation of the High-Resolution Seismic Stratigraphy Beneath Lake Michigan: United States Geological Survey Open File Report 91-21, 42 p.
FRASER, G. S., and J. C. COBB, 1982, Late Wisconsinan proglacial sedimentation along the West Chicago Moraine in northeastern Illinois: Journal of Sedimentary Petrology, v. 52, no. 2, p. 473-491.
FRICKE, C. A. P, and T. M. JOHNSON, 1983, The Pleistocene stratigraphy and geomorphology of central-southern Wisconsin and part of northern Illinois: Geological and Natural History Survey Geoscience Wisconsin, v. 8, p. 22-44.
HANSEL, A. K., and W. H. JOHNSON, 1986, Quaternary Records of Northeastern Illinois and Northwestern Indiana: Illinois State Geological Survey Guidebook 22, 106 p.
HANSEL, A. K., and W. H. JOHNSON, 1987, Ice marginal sedimentation in a late Wisconsinan end moraine complex, northeastern Illinois, USA, in J. J. M. van der Meer, editor, Tills and Glaciotectonics: A. A. Balkema, Rotterdam, p. 97-104.
HANSEL, A. K., and W. H. JOHNSON, 1992, Fluctuations of the Lake Michigan Lobe during the late Wisconsin Subepisode: Sveriges Geologiska Undersoekning, Series Ca 81, p. 133-144.
HANSEL, A. K., J. M. MASTERS, and B. J. SOCHS, 1985a, The Beverly Section, Stop 3, in W. H. Johnson, A. K. Hansel, B. J. Socha, L. R. Follmer, and J. M. Masters, Depositional Environments and Correlation Problems of the Wedron Formation (Wisconsinan) in Northeastern Illinois: Illinois State Geological Survey Guidebook 16, p. 53-70.
JOHNSON, W. H., and A. K. HANSEL, 1989, Age, stratigraphic position, and significance of the Lemont drift, northeastern Illinois: Journal of Geology, v. 97, no. 3, p. 301-318.
JOHNSON, W. H., A. K. HANSEL, B. J. SOCHA, L. R. FOLLMER, and J. M. MASTERS, 1985b, Depositional Environments and Correlation Problems of the Wedron Formation (Wisconsinan) in North-eastern Illinois: Illinois State Geological Survey Guidebook 16, 91 p.
KEMPTON, J .P., R. A. BAUER, B. B. CURRY, W. G. DIXON, A. M. GRAESE, P. C. REED, M. L. SARGENT, and R. C. VAIDEN, 1987b, Geological-Geotechnical Studies for Siting the Superconducting Super Collider in Illinois: Results of the Fall 1984 Test Drilling Program: Illinois State Geological Survey Environmental Geology Notes 117, 102 p.
MICKELSON, D. M., and K. M. SYVERSON, in press, Pleistocene Geology of Ozaukee and Washington Counties, Wisconsin: Wisconsin Geological and Natural History Survey Bulletin 91.
SCHNEIDER, A. F., 1983, Wisconsinan stratigraphy and glacial sequence in southeastern Wisconsin, in D. M. Mickelson, and L. Clayton, editors, Late Pleistocene History of Southeastern Wisconsin: Wisconsin Geological and Natural History Survey Geoscience Wisconsin, v. 7, p. 59-85.
WELKIE, C. J., and R. P. MEYER, 1983, Geophysical evidence that the Haeger Till Member underlies southern western Lake Michigan: Wisconsin Geological and Natural History Survey Geoscience Wisconsin, v. 8, p. 45-58.
WILLMAN, H. B., and J .C. FRYE, 1970, Pleistocene Stratigraphy of Illinois: Illinois State Geological Survey Bulletin 94, 204 p.
|Stratigraphic Code||Geo Unit Designation|