Type Geological formation Primary Coarse sandstones | Unit of Potsdam Sandstone Underlies Eau Claire Formation | |
Overlies Precambrian bedrock (unconformably) Area Illinois, Indiana, Wisconsin, Michigan, Ohio, and Kentucky Thickness up to 2,000 feet (610 m) | ||
The Mount Simon Sandstone is the basal sandstone of the Potsdam Sandstone. It was deposited in a nearshore environment, unconformably overlying Precambrian basement.
It is overlain by the Eau Claire Formation or Ordovician strata. It is presumed to be Upper Cambrian in age, though not verified. See infobox for more details.
The Mount Simon formation is the equivalent of the La Motte Sandstone formation in the St. Francois Mountains of Missouri.
References
Mount Simon Sandstone Wikipedia(Text) CC BY-SA