The landforms along the Lake Michigan coast today have ages ranging
from just a couple of months to thousands of years. Dunes started
forming when the ice sheet retreated because the glacier left sediments
behind and there were strong winds to move them around. The landscape
changed as the level of the lake rose and fell, climate and ecosystems
varied, and human activities took place along the coast. Dunes grew,
eroded, became stabilized, were reactivated and were overridden
by other dunes.
Contrasting ages: the foredune in the front of
the photo is less than ten years old; the large parabolic dune
in the back of the photo is more than a thousand years old.
(Hoffmaster State Park in July 2002.)
At present, coastal dunes exist at many locations along the east and north shores of Lake Michigan. Researchers such
as Ed Hansen (Hope College) and Alan Arbogast (Michigan State University)
use a variety of techniques to reconstruct dune history, including
looking at the patterns of the landforms and dating buried soils
and dune sands.