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Paleozoic stratigraphy and kinematics of the Roberts Mountains allochthon in the Independence Mountains, northern Nevada

May 14, 2010

New biostratigraphic, stratigraphic, and structural data from deformed lower Paleozoic sedimentary units of the Roberts Mountains allochthon (RMA), Independence Mountains, Nevada, have enabled the identification of stratigraphic units within the allochthon that range in age from Late Cambrian through Late Devonian. The McAfee thrust fault emplaced a relatively thick (>200 m) sheet of Ordovician Valmy quartzite (locally termed the McAfee Quartzite) on complexly deformed units of the RMA (locally termed the Snow Canyon Formation) comprised of the Vinini Formation, Elder Sandstone, and Slaven Chert. The rocks were affected by multiple phases of deformation during and after the Devonian-Mississippian Antler orogeny, including: emplacement of the Roberts Mountains allochthon with south-vergent folding and faulting of the upper and lower plate rocks to the Roberts Mountains thrust; emplacement of Upper Mississippian (324 Ma) basalt dikes that cross-cut the upper (allochthonous) and lower (para-autochthonous) plate rocks and south-vergent folds; emplacement of the McAfee Quartzite; and upright north-trending folding after the deposition of Antler overlap rocks. Recognition of this history is required to determine the internal structure and thickness of the allochthon and location of high-angle structures within it that, respectively, may conceal and localize Carlin-type gold deposits in underlying carbonate rocks.

Publication Year 2011
Title Paleozoic stratigraphy and kinematics of the Roberts Mountains allochthon in the Independence Mountains, northern Nevada
Authors Christopher S. Holm-Denoma, Albert H. Hofstra, Stephen A. Leslie, Paula J. Noble
Publication Type Conference Paper
Publication Subtype Conference Paper
Index ID 70004424
Record Source USGS Publications Warehouse
USGS Organization Geology, Geophysics, and Geochemistry Science Center