SILURIAN, DEVONIAN, AND MISSISSIPPIAN FORMATIONS OF THE FUNERAL MOUNTAINS IN THE RYAN QUADRANGLE, DEATH VALLEY REGION, CALIFORNIA
By JAMES F. MCALLISTER
A composite section of the Silurian, Devonian, and Mississippian formations in the Funeral Mountains between Death Valley and Amargosa Valley is about 4,700 feet thick. The formations are in the top of a concordant, complexly faulted sequence that is about 25,000 feet thick from the highest part of the Precambrian to the Upper Mississippian. The Silurian and younger formations consist of marine dolomite and limestone that contain some regionally characteristic cherty and siliceous clastic beds as well as widely spaced fossiliferous zones.
The Hidden Valley Dolomite, overlying the Ordovician Ely Springs Dolomite, is 1,440 feet thick except in the southeast end of the area where it is 870 feet thick. Cherty dark dolomite in the lower part of the Hidden Valley contains Silurian (possibly Llandovery, clearly Wenlock, and probably Ludlow) fossils; dolomite in a somewhat argillaceous and silty uppermost part contains Lower Devonian (upper Emsian) fossils.
The Lost Burro Formation, 2,640 feet thick, has Middle Devonian (Givetian) fossils stratigraphically high in the lower part of the formation, which consists of dolomite above the basal Lippincott Member. It has Upper Devonian (Frasnian) fossils midway in the upper part, which consists predominantly of limestone.
The Tin Mountain Limestone, 315 feet thick, contains abundant Lower Mississippian (Kinderhookian and Osagean) fossils.
The Perdido Formation, which is incomplete and no more than 500 feet thick under unconformable Cenozoic continental rocks, consists mostly of limestone, chert, and siltstone. Fossils, which are scarce, include Upper Mississippian (Meramecian) microfossils 205 feet above the base of the Perdido.
Last Updated: 23-Jun-2009