Low-altitude organic deposits in Michigan: Evidence for pre-Woodfordian Great Lakes and paleosurfaces
Reports of 136 glacially buried organic deposits below 200 m in altitude and other related data provide a basis for identifying relicts of several low-level Pleistocene paleosurfaces in southern Michigan. The carbonaceous material is concentrated in five areas and probably represents low places on pre-Woodfordian landscapes with local base levels far lower than the present topography. These findings have implications regarding adjacent ancestral Great Lakes that existed sometime prior to final glaciation of the peninsula.