GEOHISTORY AND GEOHERITAGE OF THE KEWEENAW AND ISLE ROYALE FAULTS, MICHIGAN

An inventory of the rich geodiversity of the Keweenaw and Isle Royale region has helped to identify key geosites for the basis for a geopark proposal. In identifying these valuable sites we have discovered compelling material concerning thrust faults, a major point of discussion for geologists in the 1880s worldwide.

The Keweenaw Fault divides the Keweenaw Peninsula, having uplifted the synclinal sequence of continental flood basalts and rift-filling sediments by several kilometers. The interpretation of the field occurrences of this great fault were widely debated in geological literature (Irving, E.D. and Chamberlin, T.C., 1885, Bulletin of the United States Geological Survey No. 23, 58 pp.). Key exposures are still observable at several locations where the fault is well exposed. New models of the fault development are now being crafted by geophysicists.

Access to these sites is problematic and offers a challenge to local advocates of the geopark. However, the educational value of the historic debate surrounding thrusts suggests the need for preservation of these excellent exposures of Earth’s thrusting. Access to these important geosites affords educational and geotouristic opportunities for a diverse set of stakeholders ranging from national and state parks, local towns and museums, businesses, and Earth Science educators.

http://www.geo.mtu.edu/KeweenawGeoheritage/