Platteville Limestone
| Platteville Limestone | |
|---|---|
| Stratigraphic range: Ordovician | |
Platteville Limestone exposed in Decorah, Iowa | |
| Type | Formation |
| Underlies | Decorah Shale |
| Overlies | Glenwood Formation |
| Location | |
| Country | United States |
| Extent | Upper Midwest |
| Paleozoic Stratigraphy of the Upper Midwest, USA |
|---|
| Dates approximate |
| Maquoketa Group (446–440 Ma) |
| Galena Group (454–446 Ma) |
|
| Platteville Limestone (455–454 Ma) |
| Glenwood Shale (~455 Ma) |
| St. Peter Sandstone (~459–~455 Ma) |
| Knox Unconformity (~470-~459 Ma) |
| Knox Supergroup (~497-~470 Ma) |
The Platteville Limestone is the Ordovician limestone formation in the sedimentary sequence characteristic of the upper Midwestern United States. It is characterized by its gray color, rough texture, and numerous fossils. Its type locality is Platteville, Wisconsin. It was heavily used in the early decades of the building of Minneapolis–Saint Paul and Faribault, Minnesota.
In Illinois, the formation is elevated to group status and referred to as the Platteville Group.