Charles Lawrence Fair
Published: 2012
Total Pages: 184
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Abstract: The Roberts Mountains allochthon (RMA), the underlying autochthonous rocks, and post-orogenic strata were mapped in the Three Bar Ranch Quadrangle, Eureka County Nevada. This study demonstrates that the Ordovician Vinini Formation was structurally emplaced above the Devonian Woodruff Formation, which, in turn, was structurally emplaced over the Mississippian Webb Formation. This is consistent with the hypothesis that the RMA was emplaced on two major, telescoping thrust surfaces during the Antler orogeny. Furthermore, imbricate thrusting with the RMA further interleaved the Woodruff and Vinini formations during emplacement. Large outliers of Devonian carbonate strata of the autochthon that stand topographically above surrounding strata of the RMA were thrust into place as pieces in the lower part of the upper plate of a post-Antler east-vergent thrust, the Henderson Creek thrust fault, a post-Antler, east-vergent thrust that duplicated the structural-stratigraphic package of the RMA.