Geology of Paleozoic basinal rocks in the northern Fox Range; Washoe County, Nevada

Online access for this thesis was created in part with support from the Institute of Museum and Library Services (IMLS) administered by the Nevada State Library, Archives and Public Records through the Library Services and Technology Act (LSTA). To obtain high a quality image or document please contact the DeLaMare Library at https://unr.libanswers.com/ or call: 775-784-6945.The Fox Range in Northwestern Nevada is a typical Basin and Range fault block mountain range which has been tilted about 30° to the east, accelerating the erosion of Tertiary volcanic rocks along the steep western flanks, and exposing Paleozoic metamorphic rocks. The Paleozoic rocks consist of a very fine grained, siliceous mudstone which was regionally metamorphosed from mid-greenschist to mid-amphibolite facies producing argillite, schist, limestone, quartzite, and gneiss. These Paleozoic rocks exhibit three generations of structures. Di created the schistose and gneissic layering common throughout the range, along with abundant tight to isoclinal folds. D2 structures are dominated by two large, map-scale antiforms and occasional smaller, open to tight, east to northeast trending folds and assorted lineation’s. D3 structures are limited to a few north-south trending, open to gentle folds which affect all pre-Tertiary lithologies. These rocks were previously correlated with Upper Triassic to Lower Jurassic mudstones common in northern Nevada. Lithologic, metamorphic, structural and fossil data suggest this correlation is not valid. Instead, these rocks are Carboniferous, and most probably are correlative with clastic rocks of the upper Paleozoic Golconda allochthon