AN INTEGRATED PETROLEUM EVALUATION OF NORTHEASTERN NEVADA |
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Golconda-Antler Thrust and Mesozoic Pluton Domain The Golconda-Antler Thrust and Mesozoic Pluton Domain is characterized by Mesozoic thrusts that appear to be related to emplacement of the Golconda allochthon; minor Paleozoic thrusting related to emplacement of the Roberts Mountains allochthon; large Mesozoic plutons of Jurassic and Cretaceous age that have contact metamorphosed large parts of the northern portion of the domain; abundant, short segment, high-angle normal faults with small to moderate displacement; and a general lack of the well developed high-angle basin bounding normal faults and associated large Cenozoic basins characteristic of much of the rest of the area. The Golconda-Antler Thrust and Mesozoic Pluton Domain encloses much of northern Elko County and is well exposed in the northern Independence and northern Tuscarora Mountains, Double Mountain-Mason Mountain-Haystack Mountain area, Bull Run, Elk, Jarbidge, Copper, and Snake Mountains, HD Range, and Windermere Hills. The domain has a southern boundary along the Independence-Pequop Lineament, a western boundary along the Owyhee Plain Domain, and an eastern border along the eastern segment of the Large-Scale Fold Domain. Mesozoic thrusts are exposed throughout the area and appear to be post Pennsylvanian and Permian and pre-Triassic based upon exposures in the northern Independence, Bull Run, and Snake Mountains, and Mason Mountain area. Antler-age thrusting is present in the HD and Snake Mountains, the Independence Mountains, and in the Enright Hill area of the Mountain City Quadrangle. Perhaps the clearest evidence of Golconda thrusting is present in the northern Independence Mountains where the Late Mississippian to Early Pennsylvanian Schoonover Formation is thrust over the Ordovician Vinini Formation and Permian clastics. Thrusts in the Snake and HD Ranges are somewhat cryptic and appear at least in part to be reactivated Antler thrusts which have been later deformed by Mesozoic thrusting as well as low-angle normal faulting. The northern half of the domain has been strongly contact metamorphosed along large and small Jurassic and Cretaceous silicic and minor basic plutonic bodies. Many of the stratigraphic units exposed in the area are difficult to assign to a given formation as a result of this metamorphism. |
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