Jr. John A. Dorr – författare

In the eons before the first man set foot on Michigan soil, ancient mountain ranges yielded to the slow but irresistible forces of erosion and slipped beneath the waters of warm inland seas. Great rivers formed their deltas against the pounding surf, filling the seas to create endless swamps. The vast northern ice sheets scoured the face of the state, heaping high their rock debris as they withdrew to make way for the ancestral Great Lakes. Primitive man appeared here late, one of the last in the long parade of life which passes in review in Michigan's fossil record. In text and illustrations, Geology of Michigan tells this fascinating story. The authors, both experienced field geologists, offer descriptions of the principal geologic features of the state, explain the origin of these features, and portray the geologic evolution of Michigan from earliest times to the present. Specific topics include the geologic time scale, the geologic eras, water and wind, petroleum and natural gas, and minerals in Michigan. General principles of geology, which may be applied to the study of other regions as well, are explained with great clarity. The authors also provide a wealth of information on the origin and identification of rock and fossil specimens. Michigan collecting localities are indicated on maps and in the text, and collecting methods are expertly described. Of particular interest to students and geologists for its bibliography and synthesis of heretofore widely scattered information, this abundantly illustrated book can be read by student and layman alike as a comprehensive introduction to the fascinating geology of Michigan.