| In Newark Valley of western White Pine County, Nevada, the Upper Mississippian Diamond Peak Formation contains a sequence of dominantly fluvial coarse clastics. These reworked orogenic sediments were shed eastward off the Antler Highland onto an alluvial plain accumulating a thickness averaging over 1,500 feet.;The Diamond Peak Formation is interpreted to consist predominantly of braided channel fluvial deposits containing three general facies. The lowermost unit is a massive gravel conglomerate, the middle unit a conglomeratic sandstone, and the highest unit a sandstone. Beach deposits and shallow marine carbonate deposits are also present.;Petrographically, the sandstones in the Diamond Peak Formation range from quartzarenites to litharenites with quartz and chert being the major constituents. Excellent potential hydrocarbon reservoir rocks are present in both the quartzarenites and sublitharenites. Diagenesis has enhanced the reservoir characteristics by the formation of secondary porosity, but also has reduced permeability by the creation of iron and clays. |