Lake Superior Shoreline
August 16, 2001
The Keweenaw Peninsula of Upper Michigan extends northward into Lake Superior offering year-round recreation opportunities for the outdoors enthusiast. The spine of the peninsula is formed from ancient volcanic rock at the margin of a mid-continent rift zone. Hydrothermal fluids circulating through these basalts deposited large amounts of metallic copper which were extensively mined during the past 150 years. The colorful red and white Jacobsville sandstone in the picture above was deposited much later and is the source of local building stone. Local sandstone, conglomerate and volcanic rocks transported as glacial till and exposed by beach erosion are visible in the foreground.