| This is spectacular Lost Burro Gap in Death Valley National Park, California--scene of a truly classic mid Paleozoic Era stratigraphic section that includes the Lower Silurian to Lower Devonian Hidden Valley Dolomite, the Middle to Upper Devonian Lost Burro Formation, and the Lower Mississippian Tin Mountain Limestone. Paler-colored exposures through which the dirt path runs belong to the Middle to Upper Devonian Lost Burro Formation--here a massive accumulation of dolomite (magnesium carbonate), sandy dolomite, and quartzitic dolomite--all locally fossiliferous with stromatoporoid sponges, brachiopods, and crinoidal material. The extraordarily fossiliferous Lower Mississippian Tin Mountain Limestone is the darker-colored interval about three-quarters the way up the slope at left, directly above the reddish-brown quartzitic dolomites at the very top of the Lost Burro Formation, running along the entire skyline within this view. The Tin Mountain here provides Paleozoic seekers with loads of opportunities to photograph fossil corals, brachiopods, crinoids, bryozoans, and mollusks (gastropods, pelecypods, and ammonoid cephalopods) in situ. This photograph, by the way, was originally snapped with a Nikon 35mm camera. |