Equatorial Minnesota: Divisions of the Platteville .
The Platteville Formation is sometimes called the Platteville Limestone, but that doesn''t really fit the formation in the Twin Cities. It is true that it began as limestone, but around here the limestone was mostly altered to dolomite after deposition. Incidentally, dolomitization has done a number on most Platteville fossils around here, replacing the original calcium carbonate with less ...