PLEISTOCENE CHRONOLOGY OF THE GREAT LAKES REGION
1953
Hough, Jack L.
Most of the known exposures of laminated clays were studied in the Upper Great Lakes region. Thickness logs were made of a large percentage of the clays which appeared to be varved, or laminated in annual layers. Observations were made of beaches, river terraces, glacial lake deltas, and other features related to late-glacial events. Long core samples were taken from deep water in lake Michigan; 150 possible annual layers were found. Samples of the lake bottom materials were analyzed for mechanical composition, carbonate content, identity of clay minerals, and various organic remains. The geologic history of the Great Lakes is presented, with a discussion of the first glacial Great Lakes, lake stages in the Great Lake basins, Lake Algonquin and later Algonquin stages, Lakes Chippewa and Stanley, the Nipissing Great Lakes, the Algoma stage, and the transition from the Algoma stage to the present. Abstracts are included of papers concerning fathogram indications of bottom materials in Lake Michigan and deep-water sediments of Lake Michigan.
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