Geology of SD
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General Geology of South Dakota

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Legend Upper Cretaceous - sandstone, clay Upper Cretaceous - shale, chalk Paleozoic Lower Cretaceous - limestone, shale, sandstone Jurassic and Triassic Metamorphic Rocks Glacial Lake Deposit Late Wisconsin Glacial Sediments Illinoian Glacial Sediments Early Wisconsin Glacial Sediments Tertiary Igneous Rocks Geology in NW South Dakota Geology in SW South Dakota Geology in NE South Dakota Geology in SE South Dakota geology map