| The whitish to tan sedimentary exposures in the lower center of the image are fine clays, sands and silts that belong to what geologists call the late Pleistocene Rogers Lake Beds; the sediments accumulated roughly 15 thousand years ago in a great fresh water lake called Lake Rogers, a geologic contemporary of famous Pleistocene Lake Manly, which during late Pleistocene times stretched roughly 90 miles long by 6 to 11 miles wide, covering much of the floor of modern Death Valley to a maximum depth of more than 600 feet during its highest stand 185 to 160 thousand years ago. Mountains in background consist primarily of Paleozoic Era limestones, dolomites, shales and quartzites. Rounded black hills at base of mountains at left-center to roughly center of image represent a volcanic basalt flow of presumably recent age (within the last 10,000 years). |