DOCSLIB.ORG

Geology of Bullfrog Quadrangle & Ore Deposits Related to Bullfrog Hills

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geology of Bullfrog Quadrangle & Ore Deposits Related to Bullfrog Hills St119 ~~~~~~~~~~~~~~~st70Ko// 9>X/e,'n /idPf,O/) }~~~~~~~I-- - XlenAa Geology of Bullfrog Quadrangle and Ore Deposits Related to Bullfrog Hills Caldera, Nye County, Nevada and Inyo County, California By HENRY R. CORNWALL and FRANK J. KLEINHAMPL SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 454-J Preparedin cooperation with- the Nevada Bureau of Mines' UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1964 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page Pan A ,-....--------------....-----.b s tra c t Cenozoic rocks and voleanism-Continued Introductron duction..-- JI Bullfrog Hills caldera and associated rocks-Con. Precambrian rocks c k s Chemical composition of the rocks. J 13 Paleozoic rocksc 1 Older gravels. iS Daylight Formation. 2 Recent alluvium . I5 Age and correlation. 2 Structure. 15 Corkscrew Quartzite ..- ----- 3 Tectonic deformation. 15 Age and correlation .----. 3 Relation to Walker Lane and Las Vegas Valley Carrara Formation .- - - - - 4 shear zone ...... 17 Nopah Formation .-- - - --------- 4 Basin-range faulting - .- ... 17 Pogonip Group . ..... 5 Volcanic deformation .. 17 Eureka Quartuite .- -- - 5 Ore deposits associated with the caldera . 19 Ely Springs Dolomite -- .--- -- .- 51 Fluorspar .----.-.-----.-.--- 19 Roberts Mountains Formation ........ 5 Daisy mine .. 20 Lone Mountain Dolomite .......... .......... 5 Geologic setting .. - - 20 Other Paleozoic rocks ---------------.-. _- 6 Structure of the ore deposit. 20 Cenozoic rocks and volcanism. .... ...... 6 Nature of the ore 21 Monolithologic breccia..... 6 Production . 21 Titus Canyon Formation of Stock and Bode (1935). 7 Origin of the deposit .. .. .. 22 Bullfrog Hills caldera and associated rocks .. _._ 8 Gold _-- - -- 22 Description of the volcanic rocks. 9 Origin of the deposits . 23 Ash flowns.----Ash fio ------------------------~~-- 9 Bentonite - .---- --. 23, Air-fall tuffs .... 11 Quicksilver. ----- 23 Rhyolite flows and Intrusives ... 11 Pumicite. -----. 23 Basalt flows and intrusives . 11 Perlite. 24 Latite flows and intrusiveJ ....... 11 References cited ..- -. 24 ILLUSTRATIONS Pa" aV In pade PLArz 1. Geologic map and sections of the Bullfrog quadrangle, Nevada-California. 2. Columnar section of Paleozoic rocks on Bare Mountain. 3. Columnar section of Titus Canyon Formation of Stock and Bode (1935), 1 mile southeast of Daylight Pass, Funeral Mountains. 4. Generalized geologic map of the Bullfrog Hils and Yucca Mountain ealderas. 5. Columnar section of rocks in the Bullfrog Hills ealdera near Beatty. 6. Mine workings of the Daisy duorspar mine. 7. Geologic map of levels 3, 5, 6, and 8, Daisy fluorspar mine. S. Geologic map of levels 9 to 13, Daisy luorspar mine. 9. Longitudinal and crow sections of the Daisy fluorspar mine. Page Fiauzs 1. View of Bonanza King and Nopah Formations in Carrara Canyon, Bare Mountain. J4 2. View of Eureka Quartzite, Ely Springs Dolomite, Roberts Mountains Formation, and Lone Mountain Dolomite in Chuckwalla Canyon, Bare Mountain- ...... ... - 5 3. Rolling hills underlain by Daylight Formation, with small overlying remnant of monolithologic breccia, Grape- vine Mountains .------------------------------- 6 4. View of the Titus Canyon Formation of Stock and Bode (1935) near Daylight Pass, Funeral Mountains . 7 5. Devitrification zone of ash flow (welded tuff) Fluorspar Canyona.. 9 6-8. Photomicrograpbs of- 6. Ash flows-..; ----------- 12 7. Perlitic and spherulitic rhyolite bodies ----- ;----------------------- 14 8. Felsitic rocks. .. -----. .-------------------------- 14 9. Rhyolltic vitrophyre breccia at base of flow, upper part of Bullfrog Hills volcanic sequence ...-- 15 10. Variation diagrams of oxides versus differentiation Index of volcanic rocks In the Beatty area .-_- _-_. 16 l1. Map of major tectonic features of southwestern Nevada ..... .------- 18 12. Geologic plan of the Vanderbilt bentonite mine ....... :. ------------------- 24 ms nMWJaAS0--0 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGY OF BULLFROG QUADRANGLE AND ORE DEPOSITS RELATED TO BULLFROG HILLS CALDERA, NYE COUNTY, NEVADA, AND INYO COUNTY, CALIFORNIA By Hait R. ComvrwA and FRANK J. KLRIXHAxPL ABSTRACT operation with the Nevada Bureau of Mines during The Bullfrog quadrangle In southern Ny County. Nev., the period 1958-81. The Bare Mountain quadrangle, and eastern Inyo County. Calif., east of Death Valley, is which adjoins the Bullfrog on the east, was also underlain by Tertiary volcanic rocks, mainly In the northern part. and by Paleozole sedimentary rocks, mainly In the mapped by the present authors (Cornwall and Klein- southwestern part. hampl, 1960a, b; 1961b). The volcanic rocks are believed to have been derived from Published references to the geology of the Bullfrog a caldera, measuring 10 by 13 mites, that covers The northern quadrangle include an areal reconnaissance by Ball half of the quadrangle Rhyolitle ash flows (welded tuffs) (1907), a detailed study of the geology and ore deposits and air-fall tuffs predominate In the volcanic sequence, which also Includes extrusions and Intrusions of rhyollte, latite, ba- of the Bullfrog district by Ransoms and others (1910), salt, and basanite. The volume of ash flows (83 cubic miles) and a description of mammal-bearing sedimentary Is roughly equal to the estinated subsidence in the caldera, beds of early Oligocene age by Stock and Bode (1935). and It is probable that the violent eruption of these rocks Members of the U.S. Geological Survey identified resulted to the subsidence of the caldera because the erup- fossils collected by the authors during fieldwork. tion removed magma from an underlying chamber. A grabenlike structure extends northeaft tangentially from the Cambrian faunas were identified by Helen Duncan, south rim of the caldera and may also have resulted from C. A. Nelson, and A. R. Palmer; Ordovician, by R. J. subjacent removal of magma during the volcanic activity. Ross, Jr.; Oligocene, by D. W. Taylor. The older rocks range from Precambrian through Missis- sipplan; the section is fragmentary because of poor exposures PR.CAMBRAN ROCKS and intense deformation. These rocks have been folded and Intensely faulted, mainly by bedding-plane thrusts that moved Rocks of older Precambrian age crop out in a small northeast or southwest This deformation to considered to be area near the center of the quadrangle (pl. 1) in sec 13, related to the development of the Las Vegs Valley shear T. 12 S., R. 45 E. Quartz-muscovite-feldspar gneiss zone, which probably posses diagonally across the center of and quartz-muscovite-biotite schist have been intruded the quadrangle from southeast to northwest. Monolithologle by irregular bodies of gneissic pegmatitic granite. The breccia of dolomite and limestone In the southwestern part gneiss is light of the quadrangle probably formed by landslide of the front gray and is composed mainly of quartz of the main thrust Tertiary to Recent basin-range faults and feldspar, whereas the schist is nearly black and have moderately disrupted the rocks. contains abundant biotite and muscovite with lesser Ore mineralization appears to be concentrated near the amounts of quartz and a little feldspar. The granite margins of the subsidence structuree The three known most is nearly white, very coarse grained, and consists promising gold-silver deposits are located on the east rim of mainly the Bullfrog Hills caldera. A substanal fluorspar deposit of quartz and feldspar with minor muscovite. and a small mercury deposit ar just south of the grabenlike PALEOZOIC ROCKS structure extending east from the alders acrom the north end of Bare 'Mountain. A smll bentonite deposit is also just Cambrian rocks crop out in the southwestern part south of this struture near the calder The ore deposits of the Bullfrog quadrangle in the Grapevine and Fu- are In fracture zones, which probably served an channels for neral Mountains (pl. 1). Smaller exposures emanations from underlying magma bodiea of these and other Paleozoic rocks occur near the middle, IETRODUCTION northeast comer, and east-central margin of the quad- The Bullfrog quadrangle is in southern Nye County, rangle. Most or all of the Paleozoic rocks identified Nev., and eastern Inyo County, Calif. (fig. 11). The on Bare Mountain (Cornwall and Kleinhampl, Bullfrog Hills are in the northern half of the quad- 1961b), except for the Fluorspar Canyon Formation rangle. The Grapevine and Funeral Mountains, sepa- of Devonian age, have been found in the Bullfrog rated by Boundary Canyon, occupy the southwestern quadrangle, but due to the limited exposures and com- quarter; the town of Beatty is at the eastern edge. plex deformation, the section revealed here is frag- The geology of this quadrangle was mapped in co- mentary and far from complete. The section that was - Jo~~~~~~~~~~~~~~~~1 n2 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY measured on Bare Mountain (Cornwall and Klein- brown, oolitic to pisolitic limestone and dolomite. The hampl, 1961b) is shown on plate 2. Detailed de- coarser grained oolitic and pisolitic beds commonly scriptions of the Paleozoic rocks will not be given contain abundant archaeocyathids and pelmatozoan here except where they differ from the section already debris. The oolitic limestone or dolomite is a per- described on Bare Mountain (Cornwall and Klein- sistent marker zone; it occurs about 800 feet
Load more

Recommended publications
  • Hecastocleideae (Hecastocleidoideae)
    Chapter 16 Hecastocleideae (Hecastocleidoideae) Vicki A. Funk and D.J. Nicholas Hind HISTORICAL OVERVIEW AND MORPHOLOGY Carduoideae—'rest of the family' split (see Chapters 12 and 44) and this placement has 100% bootstrap support. Hecastodeis shockleyi A. Gray was described in 1882 and its Its current position is supported by its distinct morphol- unusual morphology and restricted distribution has made ogy and strong support from molecular data. Its near- it sought after for herbarium specimens. This shrub is est downstream neighbor, however, is somewhat tenu- easily identified because of its single flowered heads that ous, because the position of the branch just below it are re-aggregated on a receptacle in groups of one to five (Gochnatieae) has only 65% bootstrap support (Panero heads; each group of heads is subtended by a relatively and Funk 2008) and might collapse into a polytomy large spiny whitish or greenish bract (Fig. 16.1). Gray with Mutisieae s.str. If one does the phylogenetic analysis (1882) commented that is was "a remarkable addition without Hecastodeis, there is no change in the phylogeny to the few known North American Mutisieae, to stand of the family. near Ainsliaea DC. but altogether sui generis and of pecu- liar habit." According to Williams (1977) the generic name Hecastodeis, "... comes from the Greek roots, ekastos TAXONOMY meaning 'each' and kleio meaning 'to shut up'", referring to each flower having its own involucre. The species The genus is monotypic and has always been recognized was named after William H. Shockley one of the first as such since its original description by Gray (1882).
    [Show full text]
  • Discovery of Bilaterian-Type Through-Guts in Cloudinomorphs from the Terminal Ediacaran Period
    ARTICLE https://doi.org/10.1038/s41467-019-13882-z OPEN Discovery of bilaterian-type through-guts in cloudinomorphs from the terminal Ediacaran Period James D. Schiffbauer 1,2*, Tara Selly 1,2*, Sarah M. Jacquet 1, Rachel A. Merz3, Lyle L. Nelson4, Michael A. Strange5, Yaoping Cai6 & Emily F. Smith 4 The fossil record of the terminal Ediacaran Period is typified by the iconic index fossil Cloudina and its relatives. These tube-dwellers are presumed to be primitive metazoans, but resolving 1234567890():,; their phylogenetic identity has remained a point of contention. The root of the problem is a lack of diagnostic features; that is, phylogenetic interpretations have largely centered on the only available source of information—their external tubes. Here, using tomographic analyses of fossils from the Wood Canyon Formation (Nevada, USA), we report evidence of recog- nizable soft tissues within their external tubes. Although alternative interpretations are plausible, these internal cylindrical structures may be most appropriately interpreted as digestive tracts, which would be, to date, the earliest-known occurrence of such features in the fossil record. If this interpretation is correct, their nature as one-way through-guts not only provides evidence for establishing these fossils as definitive bilaterians but also has implications for the long-debated phylogenetic position of the broader cloudinomorphs. 1 Department of Geological Sciences, University of Missouri, Columbia, MO 65211, USA. 2 X-ray Microanalysis Core, University of Missouri, Columbia, MO 65211, USA. 3 Biology Department, Swarthmore College, Swarthmore, PA 19081, USA. 4 Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA.
    [Show full text]
  • 1 Running Head: SEQUENCE STRATIGRAPHY of TEXAS
    Running Head: SEQUENCE STRATIGRAPHY OF TEXAS MIDDLE PERMIAN PLATFORM CARBONATES OUTCROP-BASED CHARACTERiZATION OF LEONARDIAN PLATFORM CARBONATE IN WEST TEXAS: IMPLICATIONS FOR SEQUENCE STRATIGRAPHIC STYLES IN TRANSITIONAL ICEHOUSE-GREENHOUSE SETTINGS Stephen C. Ruppel, W. Bruce Ward1, and Eduardo E. Ariza Bureau of Economic Geology The University of Texas at Austin 1 Current address: Earthworks LLC, P.O. Box 178, Newtown, CT 06470-0178 1 ABSTRACT The Sierra Diablo Mountains of West Texas contain world class exposures of lower and middle Permian platform carbonates. As such these outcrops offer key insights into the products of carbonate deposition in the transitional icehouse/greenhouse setting of the early-mid Permian that are available in few other places in the world. They also afford an excellent basis for examing how styles of facies and sequence development vary between platform tops and platform margins. Using outcrop data and observations from over 2 mi (3 km) of continuous exposure, we collected detailed data on the facies composition and architecture of high frequency (cycle-scale) and intermediate frequency (high frequency sequence scale) successions within the Leonardian. We used these data to define facies stacking patterns along depositional dip across the platform in both low and high accommodation settings and to document how these patterns vary systematically between and within sequences . These data not only provide a basis for interpreting similar Leonardian platform successions from less well constrained outcrop and subsurface data sets but also point out some important caveats that should be considered serve as an important model for understanding depositional processes during the is part of the Permian worldwide.
    [Show full text]
  • Upper Neogene Stratigraphy and Tectonics of Death Valley — a Review
    Earth-Science Reviews 73 (2005) 245–270 www.elsevier.com/locate/earscirev Upper Neogene stratigraphy and tectonics of Death Valley — a review J.R. Knott a,*, A.M. Sarna-Wojcicki b, M.N. Machette c, R.E. Klinger d aDepartment of Geological Sciences, California State University Fullerton, Fullerton, CA 92834, United States bU. S. Geological Survey, MS 975, 345 Middlefield Road, Menlo Park, CA 94025, United States cU. S. Geological Survey, MS 966, Box 25046, Denver, CO 80225-0046, United States dTechnical Service Center, U. S. Bureau of Reclamation, P. O. Box 25007, D-8530, Denver, CO 80225-0007, United States Abstract New tephrochronologic, soil-stratigraphic and radiometric-dating studies over the last 10 years have generated a robust numerical stratigraphy for Upper Neogene sedimentary deposits throughout Death Valley. Critical to this improved stratigraphy are correlated or radiometrically-dated tephra beds and tuffs that range in age from N3.58 Ma to b1.1 ka. These tephra beds and tuffs establish relations among the Upper Pliocene to Middle Pleistocene sedimentary deposits at Furnace Creek basin, Nova basin, Ubehebe–Lake Rogers basin, Copper Canyon, Artists Drive, Kit Fox Hills, and Confidence Hills. New geologic formations have been described in the Confidence Hills and at Mormon Point. This new geochronology also establishes maximum and minimum ages for Quaternary alluvial fans and Lake Manly deposits. Facies associated with the tephra beds show that ~3.3 Ma the Furnace Creek basin was a northwest–southeast-trending lake flanked by alluvial fans. This paleolake extended from the Furnace Creek to Ubehebe. Based on the new stratigraphy, the Death Valley fault system can be divided into four main fault zones: the dextral, Quaternary-age Northern Death Valley fault zone; the dextral, pre-Quaternary Furnace Creek fault zone; the oblique–normal Black Mountains fault zone; and the dextral Southern Death Valley fault zone.
    [Show full text]
  • Draft DRECP and EIR/EIS CHAPTER II.4
    Draft DRECP and EIR/EIS CHAPTER II.4. ALTERNATIVE 1 II.4 ALTERNATIVE 1 Alternative 1 is one of five action alternatives considered and analyzed in the Desert Renewable Energy Conservation Plan (DRECP or Plan) and Environmental Impact Report/Environmental Impact Statement (EIR/EIS). The description of Alternative 1 is first provided at an interagency level (Section II.4.1), which describes all Plan elements of the alternative. After the interagency description, the individual elements of the alternative are described, including the Bureau of Land Management (BLM) Land Use Plan Amendment (LUPA) elements of the DRECP (Section II.4.2), the Natural Community Conservation Plan (NCCP) elements of the DRECP (Section II.4.3), and the General Conservation Plan (GCP) elements of the DRECP (Section II.4.4). II.4.1 Interagency Description of Alternative 1 The interagency description of Alternative 1 includes the following main sections: Overview of Alternative 1, Conservation Strategy, Monitoring and Adaptive Management Program, Description of the Covered Activities, and Plan Implementation. The description of Alternative 1 for the DRECP and EIR/EIS encompasses the overall conservation strategy and description of Covered Activities on federal and nonfederal lands (i.e., state, county, city, and privately owned lands) within the Plan Area. II.4.1.1 Overview of Alternative 1 The following provides a Plan-wide overview of Alternative 1. Alternative 1 integrates the renewable energy and resource conservation with other existing uses in the Plan Area and includes BLM LUPA elements, NCCP elements, and GCP elements. Under Alternative 1 for the DRECP, an interagency conservation strategy for the Plan Area would be established that includes a streamlined process for the permitting of renewable energy and transmission development on both federal and nonfederal lands and a BLM LUPA providing Conservation and Management Actions (CMAs) for resources throughout the Plan Area on BLM-administered lands.
    [Show full text]
  • Hydrologic Basin Death Valley California
    Hydrologic Basin Death Valley California GEOLOGICAL SURVEY PROFESSIONAL PAPER 494-B Hydrologic Basin Death Valley California By CHARLES B. HUNT, T. W. ROBINSON, WALTER A. BOWLES, and A. L. WASHBURN GENERAL GEOLOGY OF DEATH VALLEY, CALIFORNIA GEOLOGICAL SURVEY PROFESSIONAL PAPER 494-B A! description of the hydrology, geochemistry, and patternedground of the saltpan UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1966 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page Page Abstract BI Hydrology-Continued Hydrology, by Charles B. Hunt and T. W. Robinson_ - 3 Descriptions and discharges of springs and of Introduction- 3 marshes-Continued Fieldwork- 3 Discharge of springs in the Furnace Creek fault Climate- 5 zone B35 Rainfall 5 Evapotranspiration discharge from the valley floor Evaporation 7 above the saltpan 37 Temperature- 8 Divisions of the valley according to sources of Humidity- 10 ground water 37 Wind- 11 Possible sources of water at Cottonball Marsh- 37 Rock types in the Death Valley hydrologic basin --- 11 Possible source of water at springs along Fur- Hard-rock formations 12 nace Creek fault zone 38 Unconsolidated Quaternary deposits 13 Geochemistry of the saltpan by Charles B. Hunt 40 Gravel deposits 13 General features 40 Fine-grained alluvial and playa deposits - 15 Fieldwork and acknowledgments 41 Salt deposits and saliferous playa deposits- 15 Geologic
    [Show full text]
  • Death Valley National Park
    COMPLIMENTARY $3.95 2019/2020 YOUR COMPLETE GUIDE TO THE PARKS DEATH VALLEY NATIONAL PARK ACTIVITIES • SIGHTSEEING • DINING • LODGING TRAILS • HISTORY • MAPS • MORE OFFICIAL PARTNERS T:5.375” S:4.75” PLAN YOUR VISIT WELCOME S:7.375” In T:8.375” 1994, Death Valley National SO TASTY EVERYONE WILL WANT A BITE. Monument was expanded by 1.3 million FUN FACTS acres and redesignated a national park by the California Desert Protection Act. Established: Death Valley became a The largest national park below Alaska, national monument in 1933 and is famed this designation helped focus protection for being the hottest, lowest and driest on one the most iconic landscapes in the location in the country. The parched world. In 2018 nearly 1.7 million people landscape rises into snow-capped mountains and is home to the Timbisha visited the park, a new visitation record. Shoshone people. Death Valley is renowned for its colorful Land Area: The park’s 3.4 million acres and complex geology. Its extremes of stretch across two states, California and elevation support a great diversity of life Nevada. and provide a natural geologic museum. Highest Elevation: The top of This region is the ancestral homeland Telescope Peak is 11,049 feet high. The of the Timbisha Shoshone Tribe. The lowest is -282 feet at Badwater Basin. Timbisha established a life in concert Plants and Animals: Death Valley with nature. is home to 51 mammal species, 307 Ninety-three percent of the park is bird species, 36 reptile species, two designated wilderness, providing unique amphibian species and five fish species.
    [Show full text]
  • Paleozoic Rocks Antelope Valley Eureka and Nye Counties Nevada
    :It k 'I! ' Paleozoic Rocks Antelope Valley Eureka and Nye Counties Nevada GEOLOGICAL SURVEY PROFESSIONAL PAPER 423 Paleozoic Rocks of Antelope Valley Eureka and Nye Counties Nevada By CHARLES W. MERRIAM GEOLOGICAL SURVEY PROFESSIONAL PAPER 423 P,rinciples of stratigraphy applied in descriptive study of the Central Great Basin Paleozoic column UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1963 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.C. CONTENTS Page Page Silurian system ____________________________________ _ Abstract------------------------------------------- 1 36 Introduction. _____________________________________ _ 2 General features-------------------------------- 36 Geologic setting ______________ ------ ___ --------- 2 Roberts Mountains formation ___________________ _ 37 History of investigation ________________________ _ 5 Lone Mountain dolomite ______ ---_-------------- 39 Purpose and scope _____________ -- ______ ------ --- 6 Devonian system ______________ ---- __ - _- ___ - _------- 41 Acknowledgments ______________________________ _ 6 General features _____________ - ___________ -_----- 41 Geologic structure as related to stratigraphy __________ _ 6 Western Helderberg age limestones of the Monitor Paleontologic studies ______ ..:. _______ ~ ________________ _ 9 · Range ______ - _.- ___ --------------------------- 42 The Paleozoic column at Antelope Valley
    [Show full text]
  • Distribution of the Middle Ordovician Copenhagen Formation and Its Trilobites in Nevada
    Distribution of the Middle Ordovician Copenhagen Formation and its Trilobites in Nevada GEOLOGICAL SURVEY PROFESSIONAL PAPER 749 Distribution of the Middle Ordovician Copenhagen Formation and its Trilobites in Nevada By REUBEN JAMES ROSS, JR., and FREDERICK C. SHAW GEOLOGICAL SURVEY PROFESSIONAL PAPER 749 Descriptions of Middle Ordovician trilobites belonging to 21 genera contribute to correlations between similar strata in Nevada) California) and 0 klahoma UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1972 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. lVIOR TON, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director Library of Congress catalog-card No. 78-190301 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 70 cents (paper cover) Stock Number 2401-2109 CONTENTS Page Page Abstract ______________________________ -------------------------------------------------- 1 Descriptions of trilobites __________________________________________________ _ 14 Introduction ________________________________________________________________________ _ 1 Genus T1·iarth1·us Green, 1832 .... ------------------------------ 14 Previous investigations _____________________________________________ _ 1 Genus Carrickia Tripp, 1965 ____________________________________ _ 14 Acknowledgments-------------------------------------------------------· 1 Genus Hypodicranotus Whittington, 1952 _____________ _ 15 Geographic occurrences of the Copenhagen Genus Robergia Wiman, 1905·----------------------------------
    [Show full text]
  • Paleozoic Geology of the Dobbin Summit-Clear Creek Area, Monitor
    AN ABSTRACT OF THE THESIS OF DIANE CAROL WISE for the degree of MASTER OF SCIENCE in Geology presented on August 13, 1976 Title: PALEOZOIC GEOLOGY OF THE DOBBIN SUMMIT- CLEAR CREEK AREA, MONITOR RANGE, NYiE COUNTY, NEVADA Abstract approved: Redacted for Privacy son Paleozoic limestones, dolomites, quartz arenites, and other clastic rocks were mapped in the vicinity of Dobbin Summit and Clear Creek in the central Monitor Range. Sedimentary rock units present in this area represent the shallow-shelf eastern assemblage and basin and also the basin-slope facies of the traditional limestone- clastic assemblage. The four oldest, Ordovician, units were deposited in shallow shelf environments. The Lower Ordovician Goodwin Formation is composed of about 1200 feet of calcareous shales and thin-bedded limestones. The overlying Antelope Valley Limestone is about 500 feet thick and consists of wackestones, packstones, and rare algal grainstones.The Copenhagen Formation (135 feet thick) is the highest regressive deposit of sandstone, siltstone, and limestone below the transgressive Eureka Quartzite.The Eureka is a quartz arenite 181 feet thick, with an intercalated shallow marine dolomite member. The transition from shallow to deep water conditions can be seen in the change from algal boundstones to laminated lime mud- stones in the Hanson Creek Formation (190 feet thick).The super- jacent Roberts Mountains Formation (285 feet thick) is composed of lime mudstones and allodapic beds deposited in basinal, deep water conditions.During earliest Devonian
    [Show full text]
  • The Evolution of Trilobite Body Patterning
    ANRV309-EA35-14 ARI 20 March 2007 15:54 The Evolution of Trilobite Body Patterning Nigel C. Hughes Department of Earth Sciences, University of California, Riverside, California 92521; email: [email protected] Annu. Rev. Earth Planet. Sci. 2007. 35:401–34 Key Words First published online as a Review in Advance on Trilobita, trilobitomorph, segmentation, Cambrian, Ordovician, January 29, 2007 diversification, body plan The Annual Review of Earth and Planetary Sciences is online at earth.annualreviews.org Abstract This article’s doi: The good fossil record of trilobite exoskeletal anatomy and on- 10.1146/annurev.earth.35.031306.140258 togeny, coupled with information on their nonbiomineralized tis- Copyright c 2007 by Annual Reviews. sues, permits analysis of how the trilobite body was organized and All rights reserved developed, and the various evolutionary modifications of such pat- 0084-6597/07/0530-0401$20.00 terning within the group. In several respects trilobite development and form appears comparable with that which may have charac- terized the ancestor of most or all euarthropods, giving studies of trilobite body organization special relevance in the light of recent advances in the understanding of arthropod evolution and devel- opment. The Cambrian diversification of trilobites displayed mod- Annu. Rev. Earth Planet. Sci. 2007.35:401-434. Downloaded from arjournals.annualreviews.org ifications in the patterning of the trunk region comparable with by UNIVERSITY OF CALIFORNIA - RIVERSIDE LIBRARY on 05/02/07. For personal use only. those seen among the closest relatives of Trilobita. In contrast, the Ordovician diversification of trilobites, although contributing greatly to the overall diversity within the clade, did so within a nar- rower range of trunk conditions.
    [Show full text]
  • Southern Exposures
    Searching for the Pliocene: Southern Exposures Robert E. Reynolds, editor California State University Desert Studies Center The 2012 Desert Research Symposium April 2012 Table of contents Searching for the Pliocene: Field trip guide to the southern exposures Field trip day 1 ���������������������������������������������������������������������������������������������������������������������������������������������� 5 Robert E. Reynolds, editor Field trip day 2 �������������������������������������������������������������������������������������������������������������������������������������������� 19 George T. Jefferson, David Lynch, L. K. Murray, and R. E. Reynolds Basin thickness variations at the junction of the Eastern California Shear Zone and the San Bernardino Mountains, California: how thick could the Pliocene section be? ��������������������������������������������������������������� 31 Victoria Langenheim, Tammy L. Surko, Phillip A. Armstrong, Jonathan C. Matti The morphology and anatomy of a Miocene long-runout landslide, Old Dad Mountain, California: implications for rock avalanche mechanics �������������������������������������������������������������������������������������������������� 38 Kim M. Bishop The discovery of the California Blue Mine ��������������������������������������������������������������������������������������������������� 44 Rick Kennedy Geomorphic evolution of the Morongo Valley, California ���������������������������������������������������������������������������� 45 Frank Jordan, Jr. New records
    [Show full text]