Geology and Land Forms in the Boyne River Watershed
Did you know that most of the land forms that you see in the Boyne River Watershed were formed by ice? Approximately 14,000 years ago, glaciers similar to the one shown above were grinding their way toward the massive glacier that filled Lake Michigan. One huge lobe lay in Boyne Valley, the thickest part of which slowly melted defining the present shape of Lake Charlevoix. Another lobe lay in Jordan Valley and, in a similar manner, formed the South Arm of Lake Charlevoix. The hills that surround both watersheds were formed as various types of glacial moraines. The links below tell the story in more detail.
Land Forms Every feature in Boyne Valley was in some manner shaped by water and/or ice. The process was very complex but geologists have provided some excellent illustrations to help define how the hills, valleys, lakes and streams in Charlevoix County were formed as the ice receded from the lower peninsula of Michigan.
(click images to enlarge)
(The maps above are from the Army Corps of Engineers, Detroit District)
Rocks Rocks in Boyne Valley and throughout Charlevoix County are of two major types. The surface of Boyne Valley is completely covered with glacial till and glacial outwash deposits that contain many loose rocks distributed throughout the soils in the form of gravel, cobbles, and boulders. They represent material that has been torn out of bedrock deposits north of Charlevoix County by the southward moving ice of glaciers. There position in the till is random. A limestone rock from Emmet County may be found side by side with a granite boulder from hundreds of miles further north in Canada.
The other type of rock that underlies Charlevoix County is bedrock. There are no known surface outcrops of bedrock in Boyne Valley but,if the glacial deposits were removed, several sedimentary rock formations of limestone and shale would be exposed. The following illustrations tell some of the story.