After the regression of the Sauk Sea early in the Ordovician, the exposed craton for a time underwent vigorous erosion, due to being located in a tropical climate; indeed, at this point in the Paleozoic the North American continent roughly straddled the equator.
[1] The Tippecanoe transgression ended this period of erosion, beginning with the deposition of clean sandstones across the craton, followed by abundant carbonate deposition.
[2] In the east these carbonates gradually become shales, representing sediments eroded from highlands created in the Taconic orogeny.
At one point during the Silurian period, the Taconic highlands, were the only part of North America that was not submerged.
This article about a specific stratigraphic formation in the United States is a stub.