Mississippian Fossil Clams. Clams from The Blue Ridge Esker, Jackson, Michigan
The Blue Ridge Esker was an under Glacier River that formed as the last Ice Age retreated across Michigan
This Block contains several Mississippian Fossil Clams on a hard rock sandstone. These clams were inside a rounded sandstone cobble that was tumbled down the under glacier river and were deposited in the bend of the river near what is now Jackson, Michigan.
During the past certain parts of Michigan were covered by water. Because there were periodic storms, silt washed into the water covering the clams. Other types of creatures also lived in the area but they were more rare. These Clams abounded in the ancient seas.
The Blue Ridge Esker was formed just as the last period of glacier activity was coming to an end. Because the glaciers were melting, water was forming as rivers both above, in and under the glaciers. The Mississippian rocks that contained the clams within the Marshall Sandstone were picked up by the river and tumbled into rounded cobbles. Because there was a large bend in the river near what is now Jackson, Michigan the water slowed down and these cobbles were deposited in piles.