The Sheep Pass Formation, a record of late Cretaceous and paleogene extension within the Sevier hinterland, East-Central Nevada

摘要: The Sheep Pass Formation, a record of Late Cretaceous and Paleogene extension within the Sevier hinterland, east-central Nevada by Peter Alexander Druschke Dr. Andrew Hanson, Examination Committee Chair Associate Professor Geology University Nevada, Las Vegas hinterland western North America is considered many to be an ancient proxy for modern Andean Puna-Altiplano or Tibetan Plateau. However, controversies exist as tectonic setting overall paleogeography during Paleogene. Formation type section southern Egan Range comprises > 1 km thick sedimentary succession spanning latest Eocene, provides rare opportunity test prevailing paleogeographic models hinterland. New 1:12,000 scale field mapping in indicates that up three stratigraphic throw occurred along Ninemile fault, presently low-angle down-to-thenorthwest normal deposition section. Subsequent reactivation fault produced additional ~1 Garrett Ranch Group, which unconformably overlies U-Pb (U-Th)/He detrital zircon dating carbonate age analyses from