Late Wisconsinan drift stratigraphy of the Lake Michigan Lobe in southwestern Michigan

1986 ◽  
Vol 97 (3) ◽  
pp. 329 ◽  
Author(s):  
G. W. MONAGHAN ◽  
G. J. LARSON ◽  
G. D. GEPHART
Keyword(s):  
Lake Michigan ◽  
Late Wisconsinan ◽  
Lake Michigan Lobe

Absence of Glaciation in Illinois during Marine Isotope Stages 3 through 5

1996 ◽  
Vol 46 (1) ◽  
pp. 19-26 ◽  
Author(s):  
B. Brandon Curry ◽  
Milan J. Pavich
Keyword(s):  
Oxygen Isotope ◽  
Late Stage ◽  
Lake Michigan ◽  
Early Stage ◽  
Ice Sheet ◽  
Laurentide Ice Sheet ◽  
Argillic Horizon ◽  
Late Wisconsinan ◽  
Lake Michigan Lobe

A10Be inventory and14C ages of material from a core from northernmost Illinois support previous interpretations that this area was ice free from ca. 155,000 to 25,000 yr ago. During much of this period, from about 155,000 to 55,000 yr ago, 10Be accumulated in the argillic horizon of the Sangamon Geosol. Wisconsinan loess, containing inherited 10Be, was deposited above the Sangamon Geosol from ca. 55,000 to 25,000 yr ago and was subsequently buried by late Wisconsinan till deposited by the Lake Michigan Lobe of the Laurentide Ice Sheet. The Sangamonian interglacial stage has been correlated narrowly to marine oxygen isotope substage 5e; our data indicate instead that the Sangamon Geosol developed during late stage 6, all of stages 5 and 4, and early stage 3.

A Proposed Diachronic Revision of Late Quaternary Time-Stratigraphic Classification in the Eastern and Northern Great Lakes Area

2000 ◽  
Vol 54 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Paul F. Karrow ◽  
Aleksis Dreimanis ◽  
Peter J. Barnett
Keyword(s):  
Great Lakes ◽  
Lake Michigan ◽  
Late Quaternary ◽  
Great Lakes Region ◽  
Quaternary Deposits ◽  
Late Wisconsinan ◽  
Stratigraphic Nomenclature ◽  
Lake Michigan Lobe

A succession of stratigraphic codes (1933, 1961, 1983) has guided attempts to refine classifications and naming of stratigraphic units for Quaternary deposits of the Great Lakes region. The most recent classifications for the late Quaternary of the Lake Michigan lobe (1968) and the eastern Great Lakes (1972) have been widely used, but later work has created the need for revision. An attempt has been made to integrate the two previous classifications following the diachronic system of the 1983 Code of Stratigraphic Nomenclature. A new nomenclature for the higher, more broadly recognized units was presented in 1997. We here present the diachronic nomenclature for finer subdivisions recognized in the eastern and northern Great Lakes. Following the interglacial Sangamon Episode, the three parts of the Wisconsin Episode are further subdivided as follows: the Ontario Subepisode (former Early Wisconsinan) comprises the Greenwood, Willowvale, and Guildwood phases; the Elgin Subepisode (former Middle Wisconsinan) comprises the Port Talbot, Brimley, and Farmdale phases; and the Michigan Subepisode (former Late Wisconsinan) consists of Nissouri, Erie, Port Bruce, Mackinaw, Port Huron, Two Creeks, Onaway, Gribben, Marquette, Abitibi, and Driftwood phases. Succeeding interglacial time to the present is the Hudson Episode.

Late Wisconsinan ice-flow reconstruction for the central Great Lakes region

1985 ◽  
Vol 22 (6) ◽  
pp. 935-940 ◽  
Author(s):  
Stephen Irving Dworkin ◽  
Grahame J. Larson ◽  
G. William Monaghan
Keyword(s):  
Lake Michigan ◽  
Source Area ◽  
Heavy Mineral ◽  
Lake Huron ◽  
Georgian Bay ◽  
South Central ◽  
Mineral Assemblages ◽  
Specific Source ◽  
Late Wisconsinan ◽  
Lake Michigan Lobe

Late Wisconsinan tills from the lower peninsula of Michigan can be differentiated with respect to the Lake Michigan, Saginaw, and Huron–Erie lobes on the basis of their heavy-mineral assemblages. Using discriminant analysis, the heavy-mineral assemblages can also be associated with specific source areas on the Canadian Shield. These associations suggest that (1) the Lake Michigan Lobe flowed southwestward across a region north of Lake Huron and then into southwestern Michigan; (2) the Saginaw Lobe flowed southwestward across a region northwest of Georgian Bay and then into south-central Michigan; and (3) the Huron–Erie Lobe flowed southwestward across a region north of Georgian Bay and then southward into southeastern Michigan.Comparison of the heavy-mineral assemblages of tills from southeastern Michigan with those from younger tills just south of Lake Huron indicates that a significant westward shift in source area occurred during the retreat of the Huron–Erie Lobe from southeastern Michigan.

Glacial-Lake Outburst Erosion of the Grand Valley, Michigan, and Impacts on Glacial Lakes in the Lake Michigan Basin

1993 ◽  
Vol 39 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Alan E. Kehew
Keyword(s):  
Lake Level ◽  
Lake Michigan ◽  
Laurentide Ice Sheet ◽  
Glacial Lake ◽  
Michigan Basin ◽  
Lake Agassiz ◽  
Lake Algonquin ◽  
Lake Michigan Lobe ◽  
Possible Cause ◽  
Glacial Lake Algonquin

AbstractGeomorphic and sedimentologic evidence in the Grand Valley, which drained the retreating Saginaw Lobe of the Laurentide Ice Sheet and later acted as a spillway between lakes in the Huron and Erie basins and in the Michigan basin, suggests that at least one drainage event from glacial Lake Saginaw to glacial Lake Chicago was a catastrophic outburst that deeply incised the valley. Analysis of shoreline and outlet geomorphology at the Chicago outlet supports J H Bretz's hypothesis of episodic incision and lake-level change. Shoreline features of each lake level converge to separate outlet sills that decrease in elevation from the oldest to youngest lake phases. This evidence, coupled with the presence of boulder lags and other features consistent with outburst origin, suggests that the outlets were deepened by catastrophic outbursts at least twice. The first incision event is correlated with a linked series of floods that progressed from Huron and Erie basin lakes to glacial Lake Saginaw to glacial Lake Chicago and then to the Mississippi. The second downcutting event occurred after the Two Rivers Advance of the Lake Michigan Lobe. Outbursts from the eastern outlets of glacial Lake Agassiz to glacial Lake Algonquin are a possible cause for this period of downcutting at the Chicago outlets.

Source and Origin of Roxana Silt and Middle Wisconsinan Midcontinent Glacial Activity

1989 ◽  
Vol 31 (3) ◽  
pp. 319-331 ◽  
Author(s):  
W. Hilton Johnson ◽  
Leon R. Follmer
Keyword(s):  
Mississippi River ◽  
Lake Michigan ◽  
Drainage System ◽  
River Valley ◽  
Upper Mississippi River ◽  
Upper Great Lakes ◽  
Mississippi River Valley ◽  
Depositional System ◽  
Stratigraphic Position ◽  
Late Wisconsinan

AbstractThick Roxana Silt (middle Wisconsinan) in central and southwestern Illinois traditionally has been interpreted as loess derived from valley-train deposits in the ancient Mississippi River valley. Winters et al. (H. A. Winters, J. J. Alford, and R. L. Rieck, Quaternary Research 29, 25–35, 1988) recently suggested that the Roxana was not directly related to glacial activity, but was derived from sediment produced by increased shoreline and spillway erosion associated with a fluctuating ancestral Lake Michigan. Because (1) paleoenvironmental and paleohydrologic conditions inferred in the hypothesis are unlikely for a loess depositional system and (2) loess did not accumulate during late Wisconsinan deglaciation under conditions similar to those hypothesized, we suggest the hypothesis should be rejected. Roxana distribution suggests the major source was drainage from the upper Mississippi River valley, and variations in loess thickness in Illinois can be explained by consideration of valley width, depth, orientation, and postdepositional erosion. Tills in the headwaters region of the ancient Mississippi drainage system in Minnesota and Wisconsin occur in the appropriate stratigraphic position and have colors and mineralogic compositions that suggest they could be the parent till of the Roxana. We believe a valley-train source for thick Roxana is most probable and urge continued consideration of middle Wisconsinan glaciation in the upper Great Lakes area.

scholarly journals Evidence for Stagnation of the Harvard Sublobe (Lake Michigan Lobe) in Northeastern Illinois, U.S.A., from 24 000 to 17 600 BP and Subsequent Tundra-Like Ice-Marginal Paleoenvironments from 17 600 to 15 700 BP

2006 ◽  
Vol 58 (2-3) ◽  
pp. 305-321 ◽  
Author(s):  
Brandon B. Curry ◽  
Catherine H. Yansa
Keyword(s):  
Lake Michigan ◽  
Fine Sand ◽  
Glacial Deposits ◽  
Plant Macrofossil ◽  
Marginal Environments ◽  
Supraglacial Lakes ◽  
Last Glaciation ◽  
Salix Herbacea ◽  
Time Distance ◽  
Lake Michigan Lobe

Abstract Glacial deposits of the last glaciation associated with the Harvard sublobe (Lake Michigan lobe) in northeastern Illinois, U.S.A., occur between sediment with dateable organics. The lower organics include fragments of Picea sp. as young as 24 000 ± 270 BP. The supraglacial organics occur sparsely in laminated silt and fine sand in landforms that are positioned relatively high on the landscape, such as deposits from ice-walled lakes. These terrestrial organics yield ages that are 2500 to 1300 14C years older than organics at the base of sediment successions in nearby kettle basins. Basal 14C ages from four upland sites range from 17 610 ± 270 to 16 120 ± 80 BP. Our revised time-distance diagram of the Harvard sublobe now reflects a period of stagnation from 24 000 to about 17 600 BP. The supraglacial lacustrine silt yielded plant macrofossil assemblages of primarily tundra plants, including Salix herbacea and Dryas integrifolia. These plants likely grew in supraglacial and ice-marginal environments. The ostracode fauna include Cytherissa lacustris and Limnocythere friabilis. Geomorphic relations and ostracode ecology indicate that more than 17 m of ice buttressed some of the supraglacial lakes.

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