North-Central Section - 54th Annual Meeting - 2020

Paper No. 6-3
Presentation Time: 8:45 AM

KEWEENAW SHORELINES: SHALLOW WATER SCIENCE, HISTORY, EDUCATION AND GEO TOURISM


ROSE, William I. and VYE, Erika C., Geological and Mining Engineering and Sciences, Michigan Technological University, 1400 Townsend Dr, Houghton, MI 49931

The Earth Science of the Midcontinent Rift is beautifully exposed for researchers, teachers, students and geotourists in the Keweenaw Peninsula and Isle Royale. The exposures include exceptionally thick flood basalts ponded in the Rift Valley, spectacular cliffs of redbed sandstones, the Keweenaw thrust fault, unique copper deposits and their associated zeolite/prehnite/pumpellyite minerals, glacial moraines and outwash and many miles of lake shorelines. The shorelines are active and energetic. Waves polish the rock to reveal surfaces where rocks may be read and built into geostories of the Earth and its processes. The geosites of the peninsula are identified and have been used by fieldtrips using small motor craft, kayaks, canoes, mountain bicycles and hiking/wading. Geosites include extensive historic shipwrecks who failed to navigate the numerous rock reefs from the ridge and valley topography. The geological shoreline sites are even more dramatic highlights and include many unique geological features of very large lava flows, including large columns, vesicle sheets and cylinders, pegmatoidal layers, mafic volcaniclastic deposits, mineralized pahoehoe and fragmental flow tops, veins of hydrothermal minerals, extensive fanglomerates and redbed fluvial deposits which were quarried and used as building stones all over Eastern North America. The Keweenaw Fault crosses the shoreline several times and is also exposed in the many waterfalls of the Peninsula. In our presentation we will show examples of the many exposures. Overall this is an excellent place to highlight rift geology, if we can marshall partners who will invest for access by geotourists. This has already made significant beginnings. The Keweenaw aims to feature geo tourism efforts highlighted by its scenic and educational shorelines, both at and below the dynamic waterlines. http://www.geo.mtu.edu/KeweenawGeoheritage/