Brief outline of Pennsylvania’s Geologic History

I’m not a geologist that studies sediments and weathering. I suppose if I were, I would think that this latest stage of Pennsylvania’s geologic history was interesting. C'est la vie, eh? Once Pangea broke up, the Appalachian Mountains continued to erode and deposit sediment on their flanks and in the valleys. There also appears to have been a mild "heating up" of the edge of the continent during the Cretaceous period, resulting in very minor uplift, but things have been essentially quiet ever since then. (Recent small earthquakes are related to relaxing of the continental crust as it bounces back following the removal of the heavy continental glaciers of the ice age.)