DOCSLIB.ORG

The Sheep Pass Formation, a Record of Late Cretaceous and Paleogene Extension Within the Sevier Hinterland, East-Central Nevada

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Sheep Pass Formation, a Record of Late Cretaceous and Paleogene Extension Within the Sevier Hinterland, East-Central Nevada UNLV Theses, Dissertations, Professional Papers, and Capstones 5-2009 The Sheep Pass Formation, a record of late Cretaceous and paleogene extension within the Sevier hinterland, East-Central Nevada Peter Alexander Druschke University of Nevada, Las Vegas Follow this and additional works at: https://digitalscholarship.unlv.edu/thesesdissertations Part of the Geology Commons Repository Citation Druschke, Peter Alexander, "The Sheep Pass Formation, a record of late Cretaceous and paleogene extension within the Sevier hinterland, East-Central Nevada" (2009). UNLV Theses, Dissertations, Professional Papers, and Capstones. 1188. http://dx.doi.org/10.34917/2598944 This Dissertation is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Dissertation in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/or on the work itself. This Dissertation has been accepted for inclusion in UNLV Theses, Dissertations, Professional Papers, and Capstones by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. THE SHEEP PASS FORMATION, A RECORD OF LATE CRETACEOUS AND PALEOGENE EXTENSION WITHIN THE SEVIER HINTERLAND, EAST-CENTRAL NEVADA by Peter Alexander Druschke Bachelor of Science Sonoma State University 1999 Masters of Science University of Nevada, Las Vegas 2003 A dissertation submitted in partial fulfillment of the requirements for the Doctor of Philosophy Degree in Geoscience Department of Geoscience College of Sciences Graduate College University of Nevada, Las Vegas May 2009 UMI Number: 3384002 Copyright 2009 by Druschke, Peter Alexander INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. UMI UMI Microform 3384002 Copyright 2009 by ProQuest LLC All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 P\7^ Dissertation Approval m,^uu,.^^L, The Graduate College University of Nevada, Las Vegas March 2 ,20 09 The Dissertation prepared by Peter Alexander Druschke Entitled THE SHEEP PASS FORMATION, A RECORD OF LATE CRETACEOUS AND PALEOGENE EXTENSION WITHIN THE SEVIER HINTERLAND, EAST-CENTRAL NEVADA is approved in partial fulfillment of the requirements for the degree of Doctor of Philosophy Degree in Geoscience Examination Committee Chair Dean of the Graduate College Examination Committee Member Graduate College Faculty Representative 1017-52 11 ABSTRACT 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 of Geology University of Nevada, Las Vegas The Sevier hinterland of western North America is considered by many to be an ancient proxy for the modern Andean Puna-Altiplano or Tibetan Plateau. However, controversies exist as tectonic setting and overall paleogeography of the Sevier hinterland during the Late Cretaceous and Paleogene. The Sheep Pass Formation type section within the southern Egan Range of east-central Nevada comprises a > 1 km thick sedimentary succession spanning the latest Cretaceous to Eocene, and provides a rare opportunity to test prevailing tectonic and paleogeographic models for the Sevier hinterland. New 1:12,000 scale field mapping in the southern Egan Range indicates that up to three km of stratigraphic throw occurred along the Ninemile fault, a presently low-angle down-to-the- northwest normal fault, during deposition of the Sheep Pass Formation type section. Subsequent reactivation of the Ninemile fault produced an additional ~1 km of stratigraphic throw during deposition of the Garrett Ranch Group, which unconformably overlies the Sheep Pass Formation type section. New U-Pb and (U-Th)/He detrital zircon dating and U-Pb carbonate age analyses from the Sheep Pass Formation type section iii indicate that the Ninemile fault system was active in latest Cretaceous time, and documents for the first time the presence of surface-breaking, synconvergent normal faults within the Sevier hinterland. New U-Pb detrital zircon and 40Ar/39Ar age analyses from the overlying Garrett Ranch Group document reactivation of the Ninemile fault in the middle to late Eocene, indicating that two discrete episodes of extension affected the Sevier hinterland. Movement along the Ninemile fault was coeval with Late Cretaceous and early Paleogene mid-crustal extension within the Sevier hinterland, and suggests a possible link. Middle to late Eocene extension was coeval with extension in the Sevier foreland of central Utah, and foundering of the Farallon slab. Evidence that extension significantly predated volcanism within the Sevier hinterland invalidates the theory that Paleogene volcanism drove coeval extension. Recognition of synconvergent extensional basins within the Sevier hinterland strengthens comparisons to the modern Puna- Altiplano and Tibetan plateau, where similar processes have been documented. IV TABLE OF CONTENTS ABSTRACT iii LIST OF FIGURES viii ACKNOWLEDGEMENTS ix CHAPTER 1 DISSERTATION OVERVIEW 1 CHAPTER 2 SYNCONVERGENT SURFACE-BREAKING NORMAL FAULTS OF LATE CRETACEOUS AGE WITHIN THE SEVIER HINTERLAND, EAST-CENTRAL NEVADA 6 Abstract 6 Introduction .7 Previous Work: The Sheep Pass Formation 9 Revised Age Control: U-Pb and (U-Th)/He Detrital Zircon Dating 10 Revised Age Control: U-Pb Microbial Carbonate Dating 11 New Structural Interpretations: TheNinemile Fault 12 New Structural Interpretations: Intra-basinal Faulting and Influence on Stratigraphy 13 Discussion and Conclusions 14 Figure Captions : 16 CHAPTER 3 PALEOGEOGRAPHIC ISOLATION OF THE CRETACEOUS TO EOCENE SEVIER HINTERLAND, EAST-CENTRAL NEVADA: INSIGHTS FROM U-Pb AND (U-Th)/He DETRITAL ZIRCON AGES OF HINTERLAND STRATA 20 Abstract : 20 Introduction 21 Geologic Background: Pre-Mesozoic Framework 25 Geologic Background: Mesozoic to Cenozoic Tectonic Framework 26 Cretaceous-Eocene Hinterland Stratigraphy: Newark Canyon Formation 30 Cretaceous-Eocene Hinterland Stratigraphy: Sheep Pass Formation 31 Cretaceous-Eocene Hinterland Stratigraphy: Eocene Volcanism and "Tuffaceous" Sheep Pass Formation 34 Methods: U-Pb Zircon Geochronology 37 Methods: (U-Th)/He Zircon Thermochronology 39 U-Pb Detrital Zircon Geochronology Results: Scotty Wash Sandstone 40 U-Pb Detrital Zircon Geochronology Results: Newark Canyon Formation 41 U-Pb Detrital Zircon Geochronology Results: Sheep Pass Formation Type v Section 42 U-Pb Detrital Zircon Geochronology Results: Stinking Spring Conglomerate 44 U-Pb Detrital Zircon Geochronology Results: "Tuffaceous" Sheep Pass Formation 44 (U-Th)/He Detrital Zircon Thermochronology Results 48 Discussion: Zircon Provenance 48 Discussion: Tectonic and Paleogeographic Interpretations 57 Conclusions 62 Figure Captions 65 CHAPTER 4 STRUCTURAL, STRATIGRAPHIC, AND GEOCHRONOLOGICAL EVIDENCE FOR EXTENSION PREDATING PALEOGENE VOLCANISM IN THE SEVIER HINTERLAND OF EAST-CENTRAL NEVADA 81 Abstract 81 Introduction 82 Regional Tectonic Framework 86 Background: The Sheep Pass Formation 89 40Ar/39Ar Geochronology Methods 93 40Ar/39Ar Geochronology Results: The Egan Range 94 Ar/3 Ar Geochronology Results: The Schell Creek Range 97 Paleocurrent Analysis Methods and Results 99 Late Cretaceous to Paleogene Structure and Stratigraphy of the Egan and Schell Creek Ranges: The Blue Spring Fault System 100 Late Cretaceous to Paleogene Structure and Stratigraphy of the Egan and Schell Creek Ranges: The Tectonic Significance of the Basal Garrett Ranch Group in the Southern Egan Range 102 Late Cretaceous to Paleogene Structure and Stratigraphy of the Egan and Schell Creek Ranges: The Shingle Pass Fault 104 Late Cretaceous to Paleogene Structure and Stratigraphy of the Egan and Schell Creek Ranges: The Schell Creek Range 105 Late Cretaceous to Paleogene Structure and Stratigraphy of the Egan and Schell Creek Ranges: Seismites in the Sevier Hinterland? 107 Discussion: Paleogene Extension in the Sevier Hinterland of East-Central Nevada 110 Discussion: Implications for Paleogeography of the Sevier Hinterland 114 Conclusions 118 Figure Captions 121 APPENDIX I U-Pb DETRITAL ZIRCON ANALYSES on cd rom APPENDIX II (U-Th)/He DETRITAL ZIRCON ANALYSES on cd rom APPENDIX III U-Pb CARBONATE ANALYSES on cd rom APPENDIX IV 40Ar/39Ar ANALYSES on cd rom VI APPENDIX V PALEOCURRENT DATA on cd rom REFERENCES CITED 138 VITA 162 vn LIST OF FIGURES CHAPTER 2 Figure 1: Geologic maps of Sevier hinterland and Egan Range 13 Figure 2: Detrital zircon and U-Pb carbonate age plots 13 Figure 3: Detailed geologic maps of Sheep Pass andNinemile Canyons 14 CHAPTER 3 Figure 1: Geologic map of the western U.S. Cordillera 65 Figure 2: Geologic map of Nevada 66 Figure 3: Stratigraphic
Load more

Recommended publications
  • Regional Structural Setting of Yucca Mountain, Southwestern Nevada
    ) i WM RECORD COPY I: // lt- USGS-OFR-84-854 - USGS-OFR-84-854 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY REGIONAL STRUCTURAL SETTING OF YUCCA MOUNTAIN, SOUTHWESTERN NEVADA, AND LATE CENOZOIC RATES OF TECTONIC ACTIVITY IN PART OF THE SOUTHWESTERN GREAT BASIN, NEVADA AND CALIFORNIA by U. J. Carr 06 : . , CD CD. Open-File Report 84-854 Prepared in cooperation with the Nevada Operations Office U.S. Department of Energy (Interagency Agreement DE-AI08-78ET44802) This report is preliminary and has not been reviewed for-conformity with U.S. Geological Survey editorial standards and stratigraphic nomenclature. Company names are for descriptive purposes only and do not constitute endorsement by the U.S. Geological Survey. Denver, Colorado 1984 ~~- ~ - ~~ ___~~~ Copies of this Open-File Report may be purchased from Open-File Services Secton Branch of Distribution U.S. Geological Survey Box 25425, Federal Center Denver, Colorado 80225 PREPAYMENT IS REQUIRED Price information will be published in the monthly listing 'New Publications of the Geological Survey" FOR ADDITIONAL ORDERING INFORMATION CALL: Commercial: (303) 236-7476 FTS: 776-7476 USGS-OFR-84-854 USGS-OFR-84-854 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY Denver, Colorado REGIONAL STRUCTURAL SETTING OF YUCCA MOUNTAIN, SOUTHWESTERN NEVADA, AND LATE CENOZOIC RATES OF TECTONIC ACTIVITY IN PART OF THE SOUTHWESTERN GREAT BASIN, NEVADA AND CALIFORNIA by W. J. Carr CONTENTS Page Abstract................................................................... 1 Introduction.................................................................................................. 4 Structural-physiographic subsections of the southwestern Great Basin ....... 9 Walker Lane belt ........................................ ...... ** 9 Basin-range subsection ..................................................21 Inyo-Mono subsection ............................................................26 Boundary between Inyo-Mono and Walker Lane belt subsections ......
    [Show full text]
  • Late Cenozoic Paleogeographic Evolution of Northeastern Nevada: Evidence from the Sedimentary Basins
    Late Cenozoic paleogeographic evolution of northeastern Nevada: Evidence from the sedimentary basins Alan R. Wallace* U.S. Geological Survey, MS 176, Mackay School of Earth Sciences and Engineering, University of Nevada, Reno, Nevada 89557, USA Michael E. Perkins* Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA Robert J. Fleck* U.S. Geological Survey, 345 Middlefi eld Road, Menlo Park, California 94025, USA ABSTRACT lier faults are more pronounced east of the hot-spring deposits formed at and near the Tuscarora Mountains, possibly refl ecting a paleosurface in the Chimney, Ivanhoe, and Field and geochronologic studies of Neo- hanging-wall infl uence related to uplift of the Carlin basins as those basins were forming. gene sedimentary basins in northeastern Ruby Mountains-East Humboldt core com- The Neogene geologic and landscape evolu- Nevada document the paleogeographic and plex on the east side of the Elko basin. The tion had variable effects on all of these depos- geologic evolution of this region and the later faults are concentrated along the north- its, including uplift, weathering, supergene effects on major mineral deposits. The broad northwest–trending northern Nevada rift enrichment, erosion, and burial, depending area that includes the four middle Miocene west of the Tuscarora Mountains. The area on the events at any particular deposit. As basins studied—Chimney, Ivanhoe, Car- west of the rift contains major tilted horsts such, this study documents the importance of lin, and Elko, from west to east—was an and alluvium-fi lled grabens, and differential evaluating post-mineralization processes at upland that underwent prolonged middle extension between this more highly extended both regional and local scales when exploring Tertiary exposure and moderate erosion.
    [Show full text]
  • (1987): "Tectonomagmatic Evolution of Cenozoic Extension in the North American Cordillera"
    Downloaded from http://sp.lyellcollection.org/ by Frances J Cooper on January 21, 2013 Geological Society, London, Special Publications Tectonomagmatic evolution of Cenozoic extension in the North American Cordillera Brian P. Wernicke, Philip C. England, Leslie J. Sonder and Robert L. Christiansen Geological Society, London, Special Publications 1987, v.28; p203-221. doi: 10.1144/GSL.SP.1987.028.01.15 Email alerting click here to receive free e-mail alerts when service new articles cite this article Permission click here to seek permission to re-use all or request part of this article Subscribe click here to subscribe to Geological Society, London, Special Publications or the Lyell Collection Notes © The Geological Society of London 2013 Downloaded from http://sp.lyellcollection.org/ by Frances J Cooper on January 21, 2013 Tectonomagmatic evolution of Cenozoic extension in the North American Cordillera B.P. Wernicke, R.L. Christiansen, P.C. England & L.J. Sonder SUMMARY: The spatial and temporal distributions of Cenozoic extension and magmatism in the Cordillera suggest that the onset of major crustal extension at a particular latitude was confined to a relatively narrow belt (< 100 km, pre-extension) and followed the onset of intermediate and silicic magmatism by no more than a few million years. Extension began in early Eocene time in southern British Columbia, northern Washington, Idaho and Montana. Farther S, extension began at about the Eocene- Oligocene boundary in the Great Basin and slightly later in the Mojave-Sonora Desert region. The intervening area, at the latitude of Las Vegas, remained quiescent until mid- Miocene time. Compositional and isotopic characteristics of most pre-Miocene magmas are consistent with their containing major components of melted continental crust.
    [Show full text]
  • Deformation of Intrasalt Competent Layers in Different Modes of Salt Tectonics Mark G
    Solid Earth Discuss., https://doi.org/10.5194/se-2019-49 Manuscript under review for journal Solid Earth Discussion started: 25 March 2019 c Author(s) 2019. CC BY 4.0 License. Deformation of intrasalt competent layers in different modes of salt tectonics Mark G. Rowan1, Janos L. Urai2, J. Carl Fiduk3, Peter A. Kukla4 1Rowan Consulting, Inc., Boulder, CO 80302, USA 5 2Institute for Structural Geology, Tectonics and Geomechanics, RWTH Aachen University, 52056 Aachen, Germany 3Fiduk Consulting LLC, Houston, TX 77063, USA 4Geological Institute, Energy and Mineral Resources, RWTH Aachen University, 52056 Aachen, Germany Correspondence to: Mark G. Rowan ([email protected]) 10 Abstract. Layered evaporite sequences (LES) comprise interbedded weak layers (halite and, commonly, bittern salts) and strong layers (anhydrite and usually non-evaporite rocks such as carbonates and siliciclastics). This results in a strong rheological stratification, with a range of effective viscosity up to a factor of 105. We focus here on the deformation of competent intrasalt beds in different modes of salt tectonics using a combination of conceptual, numerical and analog models, and seismic data. In bedding-paralell extension, boudinage of the strong layers forms ruptured stringers, within a 15 halite matrix, that become increasingly isolated with increasing strain. In bedding-parallel shortening, competent layers tend to maintain coherency while forming harmonic, disharmonic, and polyharmonic folds, with the rheological stratification leading to buckling and fold growth by bedding-parallel shear. In differential loading, extension and the resultant stringers dominate beneath suprasalt depocenters while folded competent beds characterize salt pillows. Finally, in tall passive diapirs, stringers generated by intrasalt extension are rotated to near vertical in tectonic melanges during upward flow of salt.
    [Show full text]
  • Tectonic Denudation of Mesozoic Contractile Structures by a Low-Angle Normal Fault and Associated Faults, Southern White Pine Range, Nevada" (1995)
    UNLV Theses, Dissertations, Professional Papers, and Capstones 12-1995 Tectonic denudation of Mesozoic contractile structures by a low- angle normal fault and associated faults, southern White Pine Range, Nevada Holly Langrock University of Nevada, Las Vegas Follow this and additional works at: https://digitalscholarship.unlv.edu/thesesdissertations Part of the Geology Commons, and the Tectonics and Structure Commons Repository Citation Langrock, Holly, "Tectonic denudation of Mesozoic contractile structures by a low-angle normal fault and associated faults, southern White Pine Range, Nevada" (1995). UNLV Theses, Dissertations, Professional Papers, and Capstones. 1420. http://dx.doi.org/10.34917/3339725 This Thesis is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Thesis in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Thesis has been accepted for inclusion in UNLV Theses, Dissertations, Professional Papers, and Capstones by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. TECTONIC DENUDATION OF MESOZOIC CONTRACTILE STRUCTURES BY A LOW-ANGLE NORMAL FAULT AND ASSOCIATED FAULTS, SOUTHERN WHITE PINE RANGE, NEVADA by Holly Langrock A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Geology Department of Geoscience University of Nevada, Las Vegas December 1995 The thesis of Holly Langrock for the degree of Master of Science in Geology is approved.
    [Show full text]
  • DIVISION C—OTHER PROVISIONS TITLE III—WHITE PINE COUNTY CON- SERVATION, RECREATION, and DE- VELOPMENT Subtitle A—Land Disp
    G:\COMP\109\WHITE PINE COUNTY CONSERVATION, RECREATION, A....XML White Pine County Conservation, Recreation, and Development Act of 2006 [Title III of division C of Public Law 109–432] [As Amended Through P.L. 116–9, Enacted March 12, 2019] øCurrency: This publication is a compilation of the text of Public Law 109–432. It was last amended by the public law listed in the As Amended Through note above and below at the bottom of each page of the pdf version and reflects current law through the date of the enactment of the public law listed at https:// www.govinfo.gov/app/collection/comps/¿ øNote: While this publication does not represent an official version of any Federal statute, substantial efforts have been made to ensure the accuracy of its contents. The official version of Federal law is found in the United States Statutes at Large and in the United States Code. The legal effect to be given to the Statutes at Large and the United States Code is established by statute (1 U.S.C. 112, 204).¿ AN ACT To amend the Internal Revenue Code of 1986 to extend expiring provisions, and for other purposes. Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, * * * * * * * DIVISION C—OTHER PROVISIONS * * * * * * * TITLE III—WHITE PINE COUNTY CON- SERVATION, RECREATION, AND DE- VELOPMENT SEC. 301. AUTHORIZATION OF APPROPRIATIONS. There are authorized to be appropriated such sums as are nec- essary to carry out this title. SEC. 302. ø16 U.S.C. 1241 note¿ SHORT TITLE This title may be cited as the ‘‘White Pine County Conserva- tion, Recreation, and Development Act of 2006’’.
    [Show full text]
  • Ni 43-101 Technical Report South Railroad Valley
    NI 43-101 TECHNICAL REPORT on the SOUTH RAILROAD VALLEY LITHIUM PROPERTY Nye County, Nevada by Edward Lyons, P.Geo. TEKHNE RESEARCH INC. Victoria, BC for BLUE EAGLE LITHIUM INC. Henderson, NV Effective Date 11 October 2018 Issue Date 15 October 2018 CERTIFICATE OF AUTHOR I, Edward Lyons, P.Geo., as an author of the technical report entitled “NI 43-101 Technical Report: South Railroad Valley Lithium Property, Nye County, Nevada” dated 15 October 2018 with the effective date of 11 October 2018 and prepared for Blue Eagle Lithium Inc. (the “Issuer”), do hereby certify that: I am currently employed as a Geological Consultant and Director of Tekhne Research Inc. with offices at 1067 Portage Road, Victoria, BC V8Z 1L1. 1) I graduated with a Bachelor of Science (Honours) degree in Geology from the University of Missouri at Rolla in 1970. 2) I am a Professional Geoscientist enrolled with the Association of Professional Engineers and Geoscientists of British Columbia (APEGBC) (Member # 122136), the Ordre des géologues du Quebec (OGQ) (Member # 701), and the Professional Engineers and geoscientist of Newfoundland and Labrador (PEGNL) (Member # 05711). 3) I have worked as a geologist for a total of 46 years since my graduation from university. My experience has included exploration and technical management on base-metal sulphide deposits in Canada for over 30 years and base-metal oxide deposits in Chile and Mexico (four years), precious metal (Au-Ag) in Canada and Mexico (six years), graphite in Canada (14 years, including as Qualified Person for ten NI 43-101 reports), and iron deposits in BC, QC, and NL (seven years, including acting as Qualified Person on five NI 43-101 reports).
    [Show full text]
  • Salt Tectonics and Its Effect on Sediment Structure and Gas Hydrate Occurrence in the Northwestern Gulf of Mexico from 2D Multichannel Seismic Data
    A Publication of the Gulf Coast Association of Geological Societies www.gcags.org SALT TECTONICS AND ITS EFFECT ON SEDIMENT STRUCTURE AND GAS HYDRATE OCCURRENCE IN THE NORTHWESTERN GULF OF MEXICO FROM 2D MULTICHANNEL SEISMIC DATA Dan’l Lewis and William Sager Department of Oceanography, Texas A&M University, MS 3146, College Station, Texas 77843–3146, U.S.A. ABSTRACT This study was undertaken to investigate mobile salt and its effect on fault structures and gas hydrate occurrence in the northwestern Gulf of Mexico. Industry 2D multichannel seismic data were used to investigate the effects of salt within an area of 7577 mi2 (19,825 km2) on the Texas continental slope in the northwestern Gulf of Mexico. The western half of the study area is characterized by a thick sedimentary wedge and isolated salt diapirs whereas the eastern half is characterized by a massive and nearly continuous salt sheet topped by a thin sedimentary section. This difference in salt characteristics marks the edge of the continuous salt sheets of the central Gulf of Mexico and is likely a result of westward decline of original salt volume. Be- neath the sedimentary wedge in the western part of the survey, an anomalous sedimentary package was found, that is described here as the diapiric, gassy sediment package (DGSP). The DGSP is highly folded at the top and is marked by tall, diapiric fea- tures. It may be either deformed shale or the toe of a complex thrust zone detaching the sedimentary wedge from deeper layers. The dataset was searched for the occurrence of bottom simulating reflectors (BSRs) because they are widely accepted as a geo- physical indicator of gas trapped beneath gas hydrate deposits that are known to occur farther east in the Gulf.
    [Show full text]
  • Three-Dimensional Evolution of Salt-Controlled Minibasins: Interactions, Folding, and Megaflap Development
    1 Aapg Bulletin Achimer September 2016, Volume 100 Issue 9 Pages 1419-1442 http://dx.doi.org/10.1306/03101614087 http://archimer.ifremer.fr http://archimer.ifremer.fr/doc/00352/46328/ © 2016. The American Association of Petroleum Geologists. All rights reserved. Three-dimensional evolution of salt-controlled minibasins: Interactions, folding, and megaflap development Callot Jean-Paul 1, *, Salel Jean-Francois 2, *, Letouzey Jean 3, *, Daniel Jean-Marc 4, *, Ringenbach Jean-Claude 5, * 1 Univ Pau & Pays Adour, Ave Univ, F-64013 Pau, France. 2 Total E&P USA, 1201 Louisiana St,Suite 1800, Houston, TX 77002 USA. 3 Univ Paris 06, Univ Paris 04, Inst Sci Terre Paris iSTeP, 4 Pl Jussieu, F-75005 Paris, France. 4 IFREMER, F-29280 Plouzane, France. 5 Total SA, Ctr Sci & Tech Jean Feger, Ave Larribau, F-64000 Pau, France. * Corresponding authors email addresses : [email protected] ; [email protected] ; [email protected] ; [email protected] ; [email protected] ; Abstract : A megaflap, or an overturned, folded, sedimentary-basin edge, is a classic feature of salt-controlled basins, formed during the inception of salt allochthony. To illustrate the relative importance of the balance between salt and sediment inputs, basin rheology, and tectonism resulting from basin interactions in the development of megaflaps, a set of analog experiments were performed in a computed tomography scanner. Sediments are modeled using both granular material and a mix of granular and viscous material and salt as purely viscous material. Uneven sedimentary loading and associated salt flow localize primary minibasins, which then migrate and expand laterally until sufficient thickness is reached to pin the downbuilding phase.
    [Show full text]
  • Carlin-Type Gold Deposits in Nevada: Critical Geologic Characteristics and Viable Models
    ©2005 Society of Economic Geologists, Inc. Economic Geology 100th Anniversary Volume pp. 451–484 Carlin-Type Gold Deposits in Nevada: Critical Geologic Characteristics and Viable Models JEAN S. CLINE,† University of Nevada, Las Vegas, 4505 Maryland Parkway, Box 454010, Las Vegas, Nevada 89154-4010 ALBERT H. HOFSTRA, Mineral Resources Program, U.S. Geological Survey, Mail Stop 973, Box 25046, Denver, Colorado 80225 JOHN L. MUNTEAN, Nevada Bureau of Mines and Geology, Mail Stop 178, University of Nevada, Reno, Nevada 89557-0088 RICHARD M. TOSDAL, AND KENNETH A. HICKEY Mineral Deposit Research Unit, University of British Columbia, 6339 Stores Road, Vancouver, British Columbia, Canada V6T 1Z4 Abstract Carlin-type Au deposits in Nevada have huge Au endowments that have made the state, and the United States, one of the leading Au producers in the world. Forty years of mining and numerous studies have pro- vided a detailed geologic picture of the deposits, yet a comprehensive and widely accepted genetic model re- mains elusive. The genesis of the deposits has been difficult to determine owing to difficulties in identifying and analyzing the fine-grained, volumetrically minor, and common ore and gangue minerals, and because of postore weathering and oxidation. In addition, other approximately contemporaneous precious metal deposits have overprinted, or are overprinted by, Carlin-type mineralization. Recent geochronological studies have led to a consensus that the Nevada deposits formed ~42 to 36 m.y. ago, and the deposits can now be evaluated in the context of their tectonic setting. Continental rifting and deposi- tion of a passive margin sequence followed by compressional orogenies established a premineral architecture of steeply dipping fluid conduits, shallow, low dipping “traps” and reactive calcareous host rocks.
    [Show full text]
  • Railroad Valley As a Result of the Survey
    State of Nevada WATER PLANNING REPORT Prepared by the State Engineer's Office, the Agricultural Experiment Station ­ University of Nevada, Reno and the Soil Conservation Service, U.S.D.A. MAY 1971 1'1.WO ). DeMICCO ROlAND D. WESTERGAJlD D_ ..... - 89701 ~AUComm~b u.. Stole ~. D1.'O"Woft ofWCller~ TO THE CITIZENS OF THE STATE OF NEVADA This Report constitutes a part of the State Water Planning effort and was prepared cooperatively by the Division of Water Resources, the Agricultural Experiment Station, University of Nevada, Reno, and the soil Conser­ vation Service, United States Department of Agriculture. The statewide reconnaissance soil survey is designed to furnish basic soil data needed to evaluate a variety of potential uses. Soil Hydrologic Groups, Soil Materials Sources, Soil Erosion Potential and Soil Irrigability Classes are among the several interpretive evaluations made in Railroad Valley as a result of the survey. The soils of the Railroad Valley area were identified~ mapped, and named according to the U. S. Comprehensive System of Soil Classi­ fication. In addition to being used in the development of the State Water Plan, the progressive reconnaissance soil sur­ vey will also contribute to an eventual soil map of Nevada which will be a basic resource data source for state, re­ gional and local land evaluation and development planning. Respectfully, (J jl J~ ~~~we~tergar~11.0 KJZ} State Engineer LIST OF TABLES TABLE 1. Temperature and Precipitation Data for Diablo Highway Maintenance Station (1959·19691 .... 25 TABLE 2. Temperature and Precipitation Data for Currant Highway Maintenance Station (1963-19691 .. 26 TABLE 3.
    [Show full text]
  • Lunar Crater Volcanic Field (Reveille and Pancake Ranges, Basin and Range Province, Nevada, USA)
    Research Paper GEOSPHERE Lunar Crater volcanic field (Reveille and Pancake Ranges, Basin and Range Province, Nevada, USA) 1 2,3 4 5 4 5 1 GEOSPHERE; v. 13, no. 2 Greg A. Valentine , Joaquín A. Cortés , Elisabeth Widom , Eugene I. Smith , Christine Rasoazanamparany , Racheal Johnsen , Jason P. Briner , Andrew G. Harp1, and Brent Turrin6 doi:10.1130/GES01428.1 1Department of Geology, 126 Cooke Hall, University at Buffalo, Buffalo, New York 14260, USA 2School of Geosciences, The Grant Institute, The Kings Buildings, James Hutton Road, University of Edinburgh, Edinburgh, EH 3FE, UK 3School of Civil Engineering and Geosciences, Newcastle University, Newcastle, NE1 7RU, UK 31 figures; 3 tables; 3 supplemental files 4Department of Geology and Environmental Earth Science, Shideler Hall, Miami University, Oxford, Ohio 45056, USA 5Department of Geoscience, 4505 S. Maryland Parkway, University of Nevada Las Vegas, Las Vegas, Nevada 89154, USA CORRESPONDENCE: gav4@ buffalo .edu 6Department of Earth and Planetary Sciences, 610 Taylor Road, Rutgers University, Piscataway, New Jersey 08854-8066, USA CITATION: Valentine, G.A., Cortés, J.A., Widom, ABSTRACT some of the erupted magmas. The LCVF exhibits clustering in the form of E., Smith, E.I., Rasoazanamparany, C., Johnsen, R., Briner, J.P., Harp, A.G., and Turrin, B., 2017, overlapping and colocated monogenetic volcanoes that were separated by Lunar Crater volcanic field (Reveille and Pancake The Lunar Crater volcanic field (LCVF) in central Nevada (USA) is domi­ variable amounts of time to as much as several hundred thousand years, but Ranges, Basin and Range Province, Nevada, USA): nated by monogenetic mafic volcanoes spanning the late Miocene to Pleisto­ without sustained crustal reservoirs between the episodes.
    [Show full text]