The Reconstructed Chronology of Coastal Dune Evolution in Michigan

Session: 26. - Valuing Great Lakes Coastal Sand Dunes: New Science and Approaches

Alan Arbogast, Department of Geography, Environment, and Spatial Sciences, Michigan State University, [email protected]
G. Monaghan, Indiana Geological Survey, Indiana University, [email protected]
William Lovis, Department of Anthropology, Michigan State University, [email protected]

Abstract

Coastal sand dunes are common in Michigan.  The largest dune fields occur on the west coast of Lower Michigan due to 1) high sand supply, 2) westerly winds, and 3) long fetch across Lake Michigan.  Smaller dune fields occur on Lower Michigan’s east coast and both shores of the Upper Peninsula.  Dunes on the west coast of Lower Michigan have been extensively studied in the past ~ 20 years, with a combined total of > 200 optical and ¹⁴C ages now published.  Prior to this work, it was assumed that the dunes largely formed in a single interval during the Nipissing lake stage ~ 5,500 years ago.  The reconstructed chronology indicates that dunes indeed began to form during that stage, but have grown episodically in the past five millennia.  Although most stable periods were short (~ 200 years), a lengthy period of dune stability occurred between ~ 1,700 and 1,000 years ago.  Renewed dune formation occurred about 1,000 years ago and about 500 years ago.  The emergent chronology, especially for the past 2,000 years, is consistent with reconstructed histories at Cape Cod and northern Europe, suggesting the hemispheric processes may influence coastal dune formation in this part of the world.

1. Keyword
sediments

2. Keyword
Lake Michigan

4. Additional Keyword
sand dunes

5. Additional Keyword
chronology