Summary of the Quaternary History of Michigan, Ohio and Indiana

Abstract

Deposits found within the Teays-Mahomet valley system show that system was blocked by ice at least two times prior to −730,000 y. Evidence of several other glaciations and of an extensive erosion interval between that time and the onset of Illinoian glaciation is also found in the subsurface. The Illinoian was a time of multiple glaciation. The Wisconsinan ice sheet, in general, did not reach quite as far south as did that of Illinoian age. Wisconsinan history can be viewed as consisting of an early episode of glaciation (Early Wisconsinan), a long interval in which the three-state area was, for the most part, ice free (Middle Wisconsinan) and a period of time (Late Wisconsinan) marked by four major episodes of ice advance, culminating at about −21,000, −15,500, −13,000 and −11,800 y, respectively. The first three of these were, in turn, marked by oscillations of the ice front. Much of our detailed knowledge of the position of the ice front during the interval from −15,500 to −10,000 y is based on study o...