| Description |
West dipping sedimentary beds in the Cherry Creek District, northern White Pine County, Nevada, range in age from latest Precambrian(?) to Permian. In the central and northern part of the area the beds exposed are principally of late Precambrian(?), Cambrian and Ordovician age. The section exposed is an exceptionally complete one composed of over 6,500 feet of basal quartzite and related rocks, nearly 9,000 feet of Camrian limestones, dolomites and shales, and approximately 3,700 feet of Ordovician limestones, shales, and quartzites and dolomites. Younger sediments are exposed at the south end of the district but were not studied in detail. The sedimentary beds are cut by several ages of faults, the earliest of which are bedding plane faults and northeast and northwest trending "tansverse" faults. A later group of structures developed following the emplacement of a large body of quartz monzonite and a smaller body of quartz diorite. The earliest post-intrusive structures to develop were north-south trending normal faults (having very low angles of dip to the east) and thrust faults. The youngest structures in the area are high-angle normal faults produced by relatively recent Basin-Range deformation. The quartz monzonite and its associated facies are exposed over a north-south length of 10 miles along the east front of the Cherry Creek and Egan Mountain Range. The igneous rock is in normal, unfaulted contact only with beds of the Cambrian-Precambrian(?) Prospect Mountain formation. Younger beds are in thrust contact with it at the south end of the area. The large quartz monzonite body and a smaller isolated quartz diorite body appear in places to have replaced up to 5000 feet of the lower Prospect Mountain formation without disturbing the overlying beds in any way. So completely absent are features suggesting forceful intrustion that some other mode of emplacement must be called upon. Magmatic stoping or metasomatic replacement are two equally tenable possibilities. Gold, silver and tungsten deposits have been mined in the Cherry Creek District during various periods since 1861. Production has come entirely from veins and bedding replacement deposits. The veins have been most productive when they cut the Prospect Mountain quartzite. The bedding replacement deposits occur exclusively in restricted horizons of the Cambrian carbonate and shale section. Total value of metals produced to date from the Cherry Creek District likely is near $6,500,00. Accompanying map available at https://collections.lib.utah.edu/ark:/87278/s6034qb7 |
