Perched Dunes

Loreen Niewenhuis is an author, adventurer, and dynamic speaker. 

She has completed a trilogy of 1,000-mile adventures exploring the Great Lakes and has authored three books about these adventures: 

A 1,000-Mile Walk on the Beach  [A Heartland Indie Bestseller]

A 1,000-Mile Great Lakes Walk   [Winner of the Great Lakes Great Reads Award] 

A 1,000-Mile Great Lakes Island Adventure  [Long-listed for the Chautauqua Prize]

 

To learn more about her work, or to engage her as a speaker, go to http://www.laketrek.com/great-lakes-speaker/

Did you know that there are different types of sand dunes? Along the Sleeping Bear Dunes National Lakeshore (stretching between Leland and Frankfort in NW lower Michigan), you'll find a unique type of dune called a 

PERCHED DUNE.

These dunes will be steeper than dunes formed only from sand because perched dunes have layers of stone mixed in with the sand which helps to stabilize the steeper face of the dune.

Rains wash out the sand revealing the stone layers

These mixed dunes were formed when the glaciers melted, dropping their loads of rocks and sand into huge piles. Often, a glacier would be melting at the same rate it was advancing, acting like a conveyer for the tons of sand and rocks carried within the mountain of ice. 

The glaciers were over a mile tall when they covered the Great Lakes Basin!

Stone layers at base of dune

 The stones within the dune have not been tumbled by the lake, so they have sharper edges.

Stones from within dune

 There are a lot of granite stones and boulders along Lake Michigan, but ALL of these stones were transported here by glaciers from the Canadian Shield.

Granite found along Lake Michigan

Enjoy a bit of video from along Lake Michigan, south of Leland, MI: