- Source: Glenwood Shale
The Glenwood Shale is a thin Ordivician shale formation in the sedimentary sequence characteristic of the upper Midwestern United States.
It lies under the Platteville Limestone and above the Saint Peter Sandstone. Together, these three units represent a sequence of sea level rise during Ordovician time. Because it is often very thin (~10 cm or less in the Twin Cities), it is often ignored in the general stratigraphy.
References
University of Minnesota: River Bluffs homepage Archived 2008-09-28 at the Wayback Machine
Kata Kunci Pencarian:
- Glenwood Shale
- St. Peter Sandstone
- Minnehaha Park (Minneapolis)
- Platteville Limestone
- History of Saint Paul, Minnesota
- Galena Group
- Sinnipee Group
- Maquoketa Group
- Decorah Shale
- Battlement Mesa, Colorado
