Date of Award
Master of Science
Geological and Environmental Sciences
Dr. Alan E. Kehew
Dr. Robb Gillespie
Dr. Duane R. Hampton
Michigan, Saginaw lobe, glacial stratigraphy, tunnel valley, glaciolacustrine
Masters Thesis-Open Access
Between 2006 and 2012, twelve rotasonic borings were drilled in Barry and Calhoun Counties, south central Michigan, as part of several Great Lakes Geological Mapping Coalition projects. Natural gamma ray logs were collected at every location and a detailed description and textural analysis was completed for seven of these cores. Five of the seven analyzed cores reached bedrock. Six of the seven borings were drilled north of the Kalamazoo Moraine of the Saginaw Lobe, which was constructed during retreat of the lobe after the Late Glacial Maximum. Five borings, drilled in tunnel valleys, indicate an increase in depth of tunnel valley incision with proximity to the glacier margin. Two cores, BA-10-02 and BA-09-02, contain at least 3 or more distinct diamicton units separated by thick lacustrine sequences. These lacustrine sequences indicate the presence of one or more proglacial and/or subglacial lakes north of the Kalamazoo Moraine. Bedrock topography may have been an important control in meltwater impoundment and lake formation. The only core located south of the Kalamazoo Moraine contains 4 diamictons, separated by sand and gravel units rather than lacustrine sediment. It is currently not known whether the diamictons represent distinct advances of the ice or a fluctuating ice margin.
Ewald, Stephanie K., "Stratigraphic Framework for Deposits of the Saginaw Lobe, Barry and Calhoun Counties, Michigan, USA" (2012). Masters Theses. 96.