| Looking essentially due westward into the fossiliferous Upper Pleistocene Sehoo Formation badlands. The Sehoo accumulated due to stream discharges of silts and clays (in addition to occasional rains of ash from distant volcanic eruptions) into a great pluvial lake (a body of water that owns its existence primarily to rains) that came into existence during an extremely rainy, wet interglacial period of the late Pleistocene Epoch. Geologists have determined that the Sehoo depositional interval of the lake lasted from approximately 24,000 to 13,000 years ago. By 12,000 years ago, most of the once-extensive pluvial lakes of the northern Great Basin had all but dried up. |