Structure and stratigraphy of the Potosi Mountain area, Southern Spring Mountains, Nevada

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dc.contributor.advisorBurchfiel, B. C.en_US
dc.creatorCameron, Christopher Scotten_US
dc.date.accessioned2018-12-18T21:25:34Zen_US
dc.date.available2018-12-18T21:25:34Zen_US
dc.date.issued1978en_US
dc.description.abstractThe Potosi Mountain area is located 25 miles southwest of Las Vegas, Nevada, along the eastern margin of the Cordilleran foreland thrust belt. Three structural blocks are exposed, including, from lowest to highest, the autochthon, the Contact thrust plate and the Keystone thrust plate. Both thrust plates contain a similar sequence of Middle Cambrian through Permian shelf carbonates. The presence of the Upper Ordovician (?) Mountain Springs Formation in both indicates a similar marginal miogeoclinal paleogeographic affinity. Triassic to Latest Jurassic (?) strata of cratonic facies are exposed in the autochthonous block. The Contact thrust, exposed east of Potosi Mountain, carries Paleozoic carbonate rocks east-northeastward over autochthonous Jurassic Aztec Sandstone, or locally, Latest Jurassic (?) synorogenic conglomerates. The Contact thrust plate is truncated north of Potosi Mountain by the northwest trending Cottonwood fault. The Keystone thrust plate overrides the Contact thrust plate south of this fault, and the autochthon to the north. The Cottonwood fault downdrops the Keystone thrust only 2 feet. The following sequence of structural events was deduced: 1) inferred high angle faulting of the autochthon; 2) east vergent folding within the future Contact thrust plate; 3) emplacement of the Contact and intraplate Potosi thrusts; 4) high angle faulting of the autochthon and Contact thrust plates (development of Cottonwood fault and Ninetynine fault zone); 5) emplacement of the Keystone thrust; 6) minor high angle faulting; and 7) minor gravity sliding. Event 1 probably predates Latest Jurassic (?) synorogenic conglomerates. Event 3 postdates these deposits and probably correlates with a folding and thrusting event dated at 135±5 M.Y.B.P. in the Clark Mountains (Burchfiel and Davis, 1971). Event 5 predates a 95±5 M.Y.B.P. post-tectonic pluton in the Clark Mountains (Burchfiel and Davis, 1971). The Keystone thrust is localized near the base of the Banded Mountain Member of the Middle Cambrian Bonanza King Formation, and similar stratigraphic control is inferred for the Contact thrust in subsurface. Cross sections indicate thrust faulting has produced a minimum 1 miles of shortening of miogeoclinal rocks in the Potosi Mountain area. The occurrence of synorogenic chert and quartzite pebble conglomerate restricted to a zone below the Contact thrust and unconformably overlying Aztec Sandstone is interpreted as evidence that the Contact thrust plate moved over an erosional surface.en_US
dc.format.digitalOriginreformatted digitalen_US
dc.format.extent102 ppen_US
dc.identifier.callnoThesis Geol. 1978 Cameronen_US
dc.identifier.citationCameron, Christopher Scott. "Structure and stratigraphy of the Potosi Mountain area, Southern Spring Mountains, Nevada." (1978) Master’s Thesis, Rice University. <a href="https://hdl.handle.net/1911/104563">https://hdl.handle.net/1911/104563</a>.en_US
dc.identifier.digitalRICE2198en_US
dc.identifier.urihttps://hdl.handle.net/1911/104563en_US
dc.language.isoengen_US
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.en_US
dc.titleStructure and stratigraphy of the Potosi Mountain area, Southern Spring Mountains, Nevadaen_US
dc.typeThesisen_US
dc.type.materialTexten_US
thesis.degree.departmentEarth Scienceen_US
thesis.degree.disciplineNatural Sciencesen_US
thesis.degree.grantorRice Universityen_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Artsen_US
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