1. Geologic Formation of Pennsylvania
Pennsylvania's land started with the idea of plate tectonics and convection currents. The mantle of the Earth is hotter than the lithosphere, which causes materials to sink and eventually rise back ... . The Eastern Industry Quarry is an open pit mine, whose rocks formed around 500-450 MYA. Limestone is a sedimentary rock formed by chemical composition. The original deposit of limestone in Pennsylvania was 500 to 1,400 feet thick. Limestone may contain graphite, quartz, and calcite, but it's mainly composed of calcite and dolomite. Bentonite is volcanic ash transformed into clay. The lighter ...
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- Grade Level: High School