Geological History--Ann Arbor Public Library's Geologic Atlas of the U.S.

The Ann Arbor area geological make-up.
System Formation Thickness Character of Rocks

Mississippian Series

Marshall Sandstone 150+ Brown, gray and yellowish sandstone. Iron Concretions near bases. "Second" brine horizon
. Cold Water Shale 670-960 Light colored, green, bluish, pinkish and gray shale's with siliceous layers and lenses of sandstone
. (60) Black, biluminous shale. May represent Sunbury shale
Berea Sandstone 65 Coarse gray sandstone. "Third" brine.
Ann Arbor Quadrangle

-glacial area

-map shows that Ann Arbor is a glacial outwash area in the center of two moraines: Fort Wayne Moraine (terminal Moraine to the West) and Defiance Moraine Outer (terminal Moraine to the East).

-glacial outwash defined: gravel deposited by glacial drainage deposits of old southwestward Huron drainage. Qgoh and clay deposits in ponded water.