| A Google Maps street car perspective that I edited and processed through photoshop. A roadcut in White Pine County, Nevada, that exposes the exact geologic contact between the lower and upper members of the middle Permian Arcturus Formation. The grayish rocks represent the lower limestone member, while that reddish-brown slope lies within the upper Arcturus member, which consists of sandstone and siltstones interlayered with platey limestone; thickness of the upper member is approximately 1,500 to 1,600 feet. The middle Permian Arcturus Formation is locally quite fossiliferous, bearing a distinctive invertebrate fauna of gastropods, pelecypods (the bivalves), brachiopods, corals, foraminifers, bryozoans, and echinoderm spines (which frequently weather free from the sedimentary matrix by the zillions). |