George F. Kay, Frank Leverett, and Paul MacClintock, 4 miles NE of Ricketts, IA, at the Nebraskan gumbotil outcrop. Photo Calvin Photographic Collection. From George Frederick Kay 1873-1943, University of Iowa. Photographed by: Earl T. Apfel, July 1925.
Frank Leverett did extensive field work in Michigan; this Michigan Digital Geology Library has many of his notebooks.
George F. Kay was my great-grandfather.