A PERSONAL REFLECTION ON THE IMPORTANT CONTRIBUTIONS OF ALAN E. KEHEW TO OUR KNOWLEDGE OF THE GLACIAL GEOLOGY OF MICHIGAN

Professor Alan E. Kehew made many important contributions to the geosciences in basic research, in teaching, in service to the profession, and in mentoring students. I discuss some key ideas and concepts that I learned from reading his papers and a few personal reflections on them and on Prof. Kehew as a scholar and scientist. I met Al Kehew in 2003 and he encouraged and supported both my teaching and research and encouraged my interactions with his many students.

In his 1993 paper on the “Glacial-lake outburst erosion of the Grand Valley, Michigan, and impacts on glacial lakes in the Lake Michigan basin”, Kehew built on the early work of J. Harlen Bretz and provided evidence for glacial lake outburst floods (GLOF’s) in the formation of the Grand River Valley and how this related to glacial lake levels. His evidence for GLOFs followed similar evidence that he and others recognized in other locations along the southern margin of the Laurentide ice sheet (e.g., Kehew 1982; Kehew and Clayton 1983; Kehew and Lord, 1986; 1987; Teller and Thorleifson 1987), which is summarized in Kehew and Teller (1994). Evidence in the Grand River Valley for GLOFs include incision and boulder lags near the outlet of Glacial Lake Saginaw, deeply incised main valley, large gravel bars and terraces, thin-sediment cover over bedrock in portions of the valley, and the straight channel sides of the valley. This work still provides an excellent working hypothesis for modern studies.

In Kehew’s papers on the late Wisconsin Saginaw and Lake Michigan lobes of the Laurentide ice sheet he and his students and collaborators produced several excellent working hypotheses, which are helping guide our work today. These hypotheses include 1) the concept of diachronous lobe advance and recession, and palimpsest tunnel valleys and other landforms (e.g., Kehew et al. 1999), 2) rapid advance over, deformation, and drumlin formation on Glacial Lake Milwaukee sediments during the Crown Point Phase (~Kalamazoo phase) of the Lake Michigan lobe (e.g., Kehew et al. 2005a), and 3) the use of landsystem-concepts to understand glacial history (e.g., Kehew et al. 2002; 2005b). These ideas and Kehew's model of a scholar and teacher provide an excellent starting point for our future work in Michigan.