DOCSLIB.ORG

Facies, Diagenesis, and Mineralogy of the Jurassic Todilto Limestone Member, Grants Uranium District, New Mexico

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Facies, Diagenesis, and Mineralogy of the Jurassic Todilto Limestone Member, Grants Uranium District, New Mexico New Mexico Bureau of Mines & Mineral Resources A DIVISION OF NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY Facies, diagenesis, and mineralogy of the Jurassic Todilto Limestone Member, Grants uranium district, New Mexico Augustus K. Armstrong U.S. Geological Survey, c/o New Mexico Bureau of Mines & Mineral Resources, Socorro, New Mexico 87801 Geotechnical Information Center SOCORRO 1995 11 NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY Daniel H. Lopez, President NEW MEXICO BUREAU OF MINES & MINERAL RESOURCES Charles E. Chapin, Director and State Geologist BOARD OF REGENTS Ex Officio Gary Johnson, Governor of New Mexico Alan Morgan, Superintendent of Public Instruction Appointed J. Michael Kelly, President, 1992-1997, Roswell Steve Torres, Secretary/Treasurer, 1991-1997, Albuquerque Charles Zimmerly, 1991-1997, Socorro Diane D. Denish, 1992-1997, Albuquerque Delilah A. Vega, Student Member, 1995-1997, Socorro BUREAU STAFF ORIN J. ANDERSON, Senior Geologist KATHRYN G. GLESENER, Manager, Cartography Section Virgil LUETH, Mineralogist/Economic Geologist RUBEN ARCHULETA, Metallurgical Lab. Tech. DEBBIE GOERING, Staff Secretary FANG LuO, Research Associate/Petroleum Engineer GEORGE S. AUSTIN, Senior Industrial Minerals Geologist IBRAHIM GUNDILER, Senior Metallurgist DAVID MCCRAW, Cartographer II ALBERT BACA, Maintenance Carpenter II WILLIAM C. HANEBERG, Assistant Director, WILLIAM McIntosh, Volcanologist/Geochronologist JAMES M. BARKER, Assistant Director, Engineering Geologist CHRISTOPHER G. McKEE, X-ray Facility Manager Senior Industrial Minerals Geologist, BRUCE HART, Petroleum Geologist VIRGINIA T MCLEMORE, Senior Economic Geologist Supervisor, Cartography Section JOHN W. HAWLEY, Senior Environmental Geologist, NORMA J. MEEKS, Director of Publications Office PAUL W. BAUER, Field Economic Geologist Manager, Albuquerque Office LISA PETERS, Lab Technician LYNN A. BRANDVOLD, Senior Chemist LYNN HEIZLER, Assistant Curator BARBARA R. POPP, Biotechnologist RON BROADHEAD, Assistant Director, Man HEIZLER, Geochronologist MARSHALL A. REITER, Senior Geophysicist Senior Petroleum Geologist, LYNNE HEMENWAY, Computer Pub./Graphics Spec. CINDIE A. SALISBURY, Cartographer II Head, Petroleum Section CAROL A. HJELLMING, Associate Editor SANDRA SWARTZ, Chemical Lab. Technician RITA CASE, Administrative Secretary (Alb. Office) GRETCHEN K. HOFFMAN, Senior Coal Geologist TERRY TELLES, Technical Secretary STEVEN M. CATHER, Field Economic Geologist GLEN JONES, Manager, Digital Cartography Laboratory REBECCA J. Titus, Senior Cartographer RICHARD CHAMBERLIN, Field Economic Geologist PHILIP KYLE, Geochemist/Petrologist JUDY M. VAIZA, Business Serv. Coordinator RICHARD R. CHAVEZ, Assistant Head, Petroleum Section ANN LANNING, Executive Secretary MANUEL J. VASQUEZ, Mechanic II RUBEN A. CRESPIN, Garage Supervisor ANNABELLE LOPEZ, Petroleum Records Clerk SUSAN J. WELCH, Manager, Geologic Extension Service NELIA DUNBAR, Analytical Geochemist THERESA L. LOPEZ, Receptionist/Staff Secretary MICHAEL WHITWORTH, Chemical Hydrogeologist ROBERT W. EVELETH, Senior Mining Engineer DAVID W. Love, Senior Environmental Geologist MAUREEN Wilks, Bibliographer NANCY S. GILSON, Assistant Editor JANE A. CALVERT LOVE, Editor JIRI ZIDEK, Chief Editor/Senior Geologist ROBERT A. BIEBERMAN, Emeritus Sr. Petroleum Geologist SAMUEL THOMPSON III, Emeritus Sr. Petroleum Geologist FRANK E. KOTTLOWSKI, Emeritus Director/State Geologist ROBERT H. WEBER, Emeritus Senior Geologist JACQUES R. RENAULT, Emeritus Senior Geologist Research Associates WILLIAM L. CHENOWETH, Grand Junction, CO BARRY S. KUES, UNM GLENN R. OSBURN, Washington Univ. CHARLES A. FERGUSON, Univ. Alberta, CAN MICHAEL J. KUNK, USGS ALLAN R. SANFORD, NMT JOHN W. GEISSMAN, UNM TIMOTHY F. LAWTON, NMSU JOHN H. SCHILLING, Reno, NV LELAND H. GILE, Las Cruces DAVID V. LEMONS, UTEP WILLIAM R. SEAGER, NMSU CAROL A. HILL, Albuquerque SPENCER G. LUCAS, NMMNH&S EDWARD W Slams, Tesuque BOB JULYAN, Albuquerque GREG H. MACK, NMSU JOHN F SUTTER, USGS SHARI A. KELLEY, SMU NANCY J. MCMILLAN, NMSU RICHARD H. TEDFORD, Amer. Mus. Nat. Hist. WILLIAM E. KING, NMSU HOWARD B. NICKELSON, Carlsbad TOMMY B. THOMPSON, CS U Graduate Students ROBERT APPELT RICHARD ESSER TINA ORTIZ ULVI CETIN JOHN GILLENTINE DAVID J. SIVILS DAVID ENNIS MICHIEL HEYNEKAMP JOE STROUD Plus about 30 undergraduate assistants Original Printing Published by Authority of State of New Mexico, NMSA 1953 Sec. 63-1-4 Printed by University of New Mexico Printing Services, December 1995 Available from New Mexico Bureau of Mines & Mineral Resources, Socorro, NM 87801 Published as public domain, therefore reproducible without permission. Source credit requested. 111 Contents ABSTRACT 5 ACICULAR-CALCITE CEMENT 21 INTRODUCTION 5 DRUSY DOGTOOTH CEMENT 21 ACKNOWLEDGMENTS 5 EQUANT-SPAR CALCITE CEMENT 21 PREVIOUS STUDIES 6 DIAGENETIC MINERALS 21 DOLOMITE ENVIRONMENTS OF DEPOSITION 6 21 LACUSTRINE DEPOSITION 6 HEMATITE 22 MARINE DEPOSITION BARITE 23 7 DETRITAL GRAINS 23 AGE 7 CLAYS 23 REGIONAL PALEOLATITUDE DETRITAL-QUARTZ AND FELDSPAR GRAINS 23 AND PALEOCLIMATES 7 CHERT 23 STRATIGRAPHY 8 X-RAY STUDIES BY CHRISTOPHER MCKEE 23 MEASURED SECTIONS 10 CARBONATE DEPOSITIONAL STRUCTURES 23 LAYERING: Coolidge section 88J-4 10 ORIGINS AND DEPOSITIONAL ENVIRONMENTS OF Continental Divide section 90J-3 11 TODILTO LAMINATIONS 23 Billy the Kid mine section 88J-3 11 INTRAFORMATIONAL FOLDS IN THE TODILTO LIMESTONE Haystack Mountain section 90J-1 12 MEMBER 25 Section Four and Nine mines 92J-1 12 Faulting associated with intraformational folds 27 Zia/La Jara mine section 90J-2 13 Todilto paleokarst 28 CARBONATE PARTICLES 13 Intraformational folds: Previous concepts 29 ORIGINS OF TODILTO LIME MUD 14 Tepee structures 30 CALCAREOUS MICROBIALITES 14 Origin of Todilto intraformational folds 31 NEOMORPHIC PROCESSES Sedimentary features of tepees absent in 14 Todilto folds 32 SKELETAL GRAINS 18 Evidence from this study 32 DASYCLADACEAN ALGAE URANIUM DEPOSITS IN THE TODILTO LIMESTONE 18 MEMBER 33 OSTRACODES 19 CONCLUSIONS 38 COMPOUND GRAINS 19 REFERENCES 38 Figures 1—Distribution of the Todilto Limestone Member in 19—Photomicrographs of sedimentary structures from New Mexico 6 the middle crinkly and upper massive zones 26 2—Jurassic nomenclature for southern San Juan Basin and 20—Diagrammatic illustration of the diagenetic history Gallup and Acoma sags (after Condon, 1989) 7 of typical Todilto ooids 27 3—Middle-Late Jurassic (middle Callovian-middle 21—Calcite pseudomorph of an anhydrite diapir bed on Oxfordian) paleogeography 8 the flank of an intraformational fold 28 4—Regional stratigraphy and correlation, lithology, and 22—Calcite pseudomorphs of diapir beds and laterally facies chart for the Todilto Limestone Member, Grants associated intraformational conglomerate beneath an uranium district, New Mexico 9 intraformational fold 28 5—Outcrop north of Coolidge section 88J-4 10 23—Intraformational fold in the middle crinkly zone, La 6—Highest beds at the Coolidge section 10 Jara mines 29 7—Continental Divide section 90J-3 11 24—Internal structures of the fold shown in Figure 23 8—Sedimentary structures in the Continental Divide sec- 29 tion 90J-3 11 25—Diapiric enterolithic structures in the middle 9—Desiccated microbial mats, Continental Divide crinkly zone 29 section 11 26—Desiccation features and a small intraformational 10—Outcrop on the highwall of Billy the Kid mine sec- fold 30 tion 88J-3 12 27—Desiccation features and flat lime-mudstone 11—Well-developed intraformational fold on the south- pebbles 30 west side of Haystack Mountain 13 28—Intraformational folds, Haystack Mountain 31 12—SEM photomicrographs of Todilto carbonates 15 29—Intraformational folds, Haystack Mountain 31 13—SEM photomicrographs of Todilto carbonates 16 30—Small intraformational fold, La Jara mines 32 14—Photomicrographs of dasycladacean algae and 31—Intraformational fold in a natural exposure, Zia/La ostracodes from the upper limestone beds of the Jara mines area 33 Coolidge section 88J-4 17 32—Penecontemporaneous, soft-sediment deformation, 15—Photomicrographs of Todilto ostracodes 18 flank of intraformational fold, Bunny mine 33 16—Photomicrographs of Todilto fossils and textures 20 33—"Massive" intraformational fold in a natural outcrop, 17—Photomicrographs of Todilto ooids 22 middle crinkly and upper massive zones, La Jara 18—Naturally weathered outcrop of the Todilto Lime- claim number 9 33 stone Member 25 34—Intraformational fold developed over an Entrada iv Sandstone paleohigh 34 38—Open pit and intraformational fold illustrating the com- 35—Open pit and tunnel into intraformational folds and plex relationship between the Todilto and Beclabito associated small fault, Bunny mine, Section Four Members, Section Nine, unnamed mine 35 area 34 39—High wall of open pit, south face, showing limestone 36—Open pit and tunnel into intraformational fold, facies relationships, karst surface, sinkholes, and Bunny mine 35 breccias, Section Nine, unnamed mine 36 37—Open pit and tunnel into intraformational fold with 40—Solution cavities and breccia, Section Nine, sinkhole, Bunny mine 35 unnamed mine 37 Table 1—X-ray diffraction analysis of mineralogy 24 5 Abstract—The Todilto Limestone Member, the basal member of the Wanakah Formation of the Grants uranium district, is 1-30 ft (0.3-9.1 m) thick and records the change in depositional environment from a restricted marine embayment with an ephemeral connection to the Curtis-Summerville Sea to a completely enclosed salina/playa and shrinking body of gypsifer- ous water. The salina measured 300 mi (483
Load more

Recommended publications
  • Hydrogeology of Jurassic and Triassic Wetlands in the Colorado Plateau and the Origin of Tabular Sandstone Uranium Deposits
    Hydrogeology of Jurassic and Triassic Wetlands in the Colorado Plateau and the Origin of Tabular Sandstone Uranium Deposits U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1548 AVAILABILITY OF BOOKS AND MAPS OF THE U.S. GEOLOGICAL SURVEY Instructions on ordering publications of the U.S. Geological Survey, along with prices of the last offerings, are given in the current-year issues of the monthly catalog "New Publications of the U.S. Geological Survey." Prices of available U.S. Geological Survey publications re­ leased prior to the current year are listed in the most recent annual "Price and Availability List." Publications that may be listed in various U.S. Geological Survey catalogs (see back inside cover) but not listed in the most recent annual "Price and Availability List" may no longer be available. Reports released through the NTIS may be obtained by writing to the National Technical Information Service, U.S. Department of Commerce, Springfield, VA 22161; please include NTIS report number with inquiry. Order U.S. Geological Survey publications by mail or over the counter from the offices listed below. BY MAIL OVER THE COUNTER Books Books and Maps Professional Papers, Bulletins, Water-Supply Papers, Tech­ Books and maps of the U.S. Geological Survey are available niques of Water-Resources Investigations, Circulars, publications over the counter at the following U.S. Geological Survey offices, all of general interest (such as leaflets, pamphlets, booklets), single of which are authorized agents of the Superintendent of Docu­ copies of Earthquakes & Volcanoes, Preliminary Determination of ments. Epicenters, and some miscellaneous reports, including some of the foregoing series that have gone out of print at the Superintendent of Documents, are obtainable by mail from • ANCHORAGE, Alaska-Rm.
    [Show full text]
  • Upper Paleozoic and Cretaceous Stratigraphy of the Hidalgo County Area, New Mexico Eugene Greenwood, F
    New Mexico Geological Society Downloaded from: http://nmgs.nmt.edu/publications/guidebooks/21 Upper Paleozoic and Cretaceous stratigraphy of the Hidalgo County area, New Mexico Eugene Greenwood, F. E. Kottlowski, and A. K. Armstrong, 1970, pp. 33-44 in: Tyrone, Big Hatchet Mountain, Florida Mountains Region, Woodward, L. A.; [ed.], New Mexico Geological Society 21st Annual Fall Field Conference Guidebook, 176 p. This is one of many related papers that were included in the 1970 NMGS Fall Field Conference Guidebook. Annual NMGS Fall Field Conference Guidebooks Every fall since 1950, the New Mexico Geological Society (NMGS) has held an annual Fall Field Conference that explores some region of New Mexico (or surrounding states). Always well attended, these conferences provide a guidebook to participants. Besides detailed road logs, the guidebooks contain many well written, edited, and peer-reviewed geoscience papers. These books have set the national standard for geologic guidebooks and are an essential geologic reference for anyone working in or around New Mexico. Free Downloads NMGS has decided to make peer-reviewed papers from our Fall Field Conference guidebooks available for free download. Non-members will have access to guidebook papers two years after publication. Members have access to all papers. This is in keeping with our mission of promoting interest, research, and cooperation regarding geology in New Mexico. However, guidebook sales represent a significant proportion of our operating budget. Therefore, only research papers are available for download. Road logs, mini-papers, maps, stratigraphic charts, and other selected content are available only in the printed guidebooks. Copyright Information Publications of the New Mexico Geological Society, printed and electronic, are protected by the copyright laws of the United States.
    [Show full text]
  • Geology and Mineral Resources of Sierra Nacimiento and Vicinity, New
    iv Contents ABSTRACT 7 TERTIARY-QUATERNARY 47 INTRODUCTION 7 QUATERNARY 48 LOCATION 7 Bandelier Tuff 48 PHYSIOGRAPHY 9 Surficial deposits 48 PREVIOUS WORK 9 PALEOTECTONIC SETTING 48 ROCKS AND FORMATIONS 9 REGIONAL TECTONIC SETTING 49 PRECAMBRIAN 9 STRUCTURE 49 Northern Nacimiento area 9 NACIMIENTO UPLIFT 49 Southern Nacimiento area 15 Nacimiento fault 51 CAMBRIAN-ORDOVICIAN (?) 20 Pajarito fault 52 MISSISSIPPIAN 20 Synthetic reverse faults 52 Arroyo Peñasco Formation 20 Eastward-trending faults 53 Log Springs Formation 21 Trail Creek fault 53 PENNSYLVANIAN 21 Antithetic reverse faults 53 Osha Canyon Formation 23 Normal faults 53 Sandia Formation 23 Folds 54 Madera Formation 23 SAN JUAN BASIN 55 Paleotectonic interpretation 25 En echelon folds 55 PERMIAN 25 Northeast-trending faults 55 Abo Formation 25 Synclinal bend 56 Yeso Formation 27 Northerly trending normal faults 56 Glorieta Sandstone 30 Antithetic reverse faults 56 Bernal Formation 30 GALLINA-ARCHULETA ARCH 56 TRIASSIC 30 CHAMA BASIN 57 Chinle Formation 30 RIΟ GRANDE RIFT 57 JURASSIC 34 JEMEZ VOLCANIC FIELD 59 Entrada Sandstone 34 TECTONIC EVOLUTION 60 Todilto Formation 34 MINERAL AND ENERGY RESOURCES 63 Morrison Formation 34 COPPER 63 Depositional environments 37 Mineralization 63 CRETACEOUS 37 Origin 67 Dakota Formation 37 AGGREGATE 69 Mancos Shale 39 TRAVERTINE 70 Mesaverde Group 40 GYPSUM 70 Lewis Shale 41 COAL 70 Pictured Cliffs Sandstone 41 ΗUMΑTE 70 Fruitland Formation and Kirtland Shale URANIUM 70 undivided 42 GEOTHERMAL ENERGY 72 TERTIARY 42 OIL AND GAS 72 Ojo Alamo Sandstone
    [Show full text]
  • Havasu Canyon Watershed Rapid Watershed Assessment Report June, 2010
    Havasu Canyon Watershed Rapid Watershed Assessment Report June, 2010 Prepared by: USDA Natural Resources Conservation Service University of Arizona, Water Resources Research Center In cooperation with: Coconino Natural Resource Conservation District Arizona Department of Agriculture Arizona Department of Environmental Quality Arizona Department of Water Resources Arizona Game & Fish Department Arizona State Land Department USDA Forest Service USDA Bureau of Land Management Released by: Sharon Megdal David L. McKay Director State Conservationist University of Arizona United States Department of Agriculture Water Resources Research Center Natural Resources Conservation Service Principle Investigators: Dino DeSimone – NRCS, Phoenix Keith Larson – NRCS, Phoenix Kristine Uhlman – Water Resources Research Center Terry Sprouse – Water Resources Research Center Phil Guertin – School of Natural Resources The United States Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, gender, religion, age, disa bility, po litica l be lie fs, sexua l or ien ta tion, an d mar ita l or fam ily s ta tus. (No t a ll prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at 202-720-2600 (voice and TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326W, Whitten Building, 14th and Independence Avenue, SW, Washington, D.C., 20250-9410 or call (202) 720-5964 (voice or TDD). USDA is an equal employment opportunity provider and employer. Havasu Canyon Watershed serve as a platform for conservation 15010004 program delivery, provide useful 8-Digit Hydrologic Unit information for development of NRCS Rapid Watershed Assessment and Conservation District business plans, and lay a foundation for future cooperative watershed planning.
    [Show full text]
  • Stromatolites in the Todilto Formation? Dana S
    New Mexico Geological Society Downloaded from: http://nmgs.nmt.edu/publications/guidebooks/56 Stromatolites in the Todilto Formation? Dana S. Ulmer-Scholle, 2005, pp. 380-388 in: Geology of the Chama Basin, Lucas, Spencer G.; Zeigler, Kate E.; Lueth, Virgil W.; Owen, Donald E.; [eds.], New Mexico Geological Society 56th Annual Fall Field Conference Guidebook, 456 p. This is one of many related papers that were included in the 2005 NMGS Fall Field Conference Guidebook. Annual NMGS Fall Field Conference Guidebooks Every fall since 1950, the New Mexico Geological Society (NMGS) has held an annual Fall Field Conference that explores some region of New Mexico (or surrounding states). Always well attended, these conferences provide a guidebook to participants. Besides detailed road logs, the guidebooks contain many well written, edited, and peer-reviewed geoscience papers. These books have set the national standard for geologic guidebooks and are an essential geologic reference for anyone working in or around New Mexico. Free Downloads NMGS has decided to make peer-reviewed papers from our Fall Field Conference guidebooks available for free download. Non-members will have access to guidebook papers two years after publication. Members have access to all papers. This is in keeping with our mission of promoting interest, research, and cooperation regarding geology in New Mexico. However, guidebook sales represent a significant proportion of our operating budget. Therefore, only research papers are available for download. Road logs, mini-papers, maps, stratigraphic charts, and other selected content are available only in the printed guidebooks. Copyright Information Publications of the New Mexico Geological Society, printed and electronic, are protected by the copyright laws of the United States.
    [Show full text]
  • CONTROLS on DOLOMITIZATION of the UPPER ORDOVICIAN TRENTON LIMESTONE in SOUTH-CENTRAL KENTUCKY COLLIN JAMES GRAY Department Of
    CONTROLS ON DOLOMITIZATION OF THE UPPER ORDOVICIAN TRENTON LIMESTONE IN SOUTH-CENTRAL KENTUCKY COLLIN JAMES GRAY Department of Geological Sciences APPROVED: Dr. Katherine Giles, Ph.D., Chair Dr. Richard Langford, Ph.D. Dr. Matthew Johnston, Ph.D. Charles Ambler, Ph.D. Dean of the Graduate School Copyright © by Collin James Gray 2015 Dedication I dedicate my thesis work to my family. My dedicated and loving parents, Michael and Deborah Gray have always supported me and provided words of encouragement during the struggles of my research. The support provided was second to none and I could not imagine reaching this point in my education without them. I also dedicate this thesis to my two brothers, Michael and Nathan Gray and my sister Nicole Gray. Without these role models I cannot imagine where my education would have ended. I will always appreciate the support provided by all three of you and consider you to be role models that I can always look up to. CONTROLS ON DOLOMITIZATION OF THE UPPER ORDOVICIAN TRENTON LIMESTONE IN SOUTH-CENTRAL KENTUCKY by COLLIN JAMES GRAY, B.S. GEOLOGY THESIS Presented to the Faculty of the Graduate School of The University of Texas at El Paso in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE Department of Geological Sciences THE UNIVERSITY OF TEXAS AT EL PASO December 2015 Acknowledgements I wish to thank my committee whose time and expertise provided excellent input into my research. Dr. Katherine Giles, my M.S. supervisor provided guidance and provided endless suggestions and recommendations throughout my research while continuously motivating me to continue my education.
    [Show full text]
  • The Geology of New Mexico As Understood in 1912: an Essay for the Centennial of New Mexico Statehood Part 2 Barry S
    Celebrating New Mexico's Centennial The geology of New Mexico as understood in 1912: an essay for the centennial of New Mexico statehood Part 2 Barry S. Kues, Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico, [email protected] Introduction he first part of this contribution, presented in the February Here I first discuss contemporary ideas on two fundamental areas 2012 issue of New Mexico Geology, laid the groundwork for an of geologic thought—the accurate dating of rocks and the move- exploration of what geologists knew or surmised about the ment of continents through time—that were at the beginning of Tgeology of New Mexico as the territory transitioned into statehood paradigm shifts around 1912. Then I explore research trends and in 1912. Part 1 included an overview of the demographic, economic, the developing state of knowledge in stratigraphy and paleontol- social, cultural, and technological attributes of New Mexico and its ogy, two disciplines of geology that were essential in understand- people a century ago, and a discussion of important individuals, ing New Mexico’s rock record (some 84% of New Mexico’s surface institutions, and areas and methods of research—the geologic envi- area is covered by sediments or sedimentary rocks) and which were ronment, so to speak—that existed in the new state at that time. advancing rapidly through the first decade of the 20th century. The geologic time scale and age of rocks The geologic time scale familiar to geologists working in New The USGS did not adopt the Paleocene as the earliest epoch of the Mexico in 1912 was not greatly different from that used by modern Cenozoic until 1939.
    [Show full text]
  • Michael Kenney Paleozoic Stratigraphy of the Grand Canyon
    Michael Kenney Paleozoic Stratigraphy of the Grand Canyon The Paleozoic Era spans about 250 Myrs of Earth History from 541 Ma to 254 Ma (Figure 1). Within Grand Canyon National Park, there is a fragmented record of this time, which has undergone little to no deformation. These still relatively flat-lying, stratified layers, have been the focus of over 100 years of geologic studies. Much of what we know today began with the work of famed naturalist and geologist, Edwin Mckee (Beus and Middleton, 2003). His work, in addition to those before and after, have led to a greater understanding of sedimentation processes, fossil preservation, the evolution of life, and the drastic changes to Earth’s climate during the Paleozoic. This paper seeks to summarize, generally, the Paleozoic strata, the environments in which they were deposited, and the sources from which the sediments were derived. Tapeats Sandstone (~525 Ma – 515 Ma) The Tapeats Sandstone is a buff colored, quartz-rich sandstone and conglomerate, deposited unconformably on the Grand Canyon Supergroup and Vishnu metamorphic basement (Middleton and Elliott, 2003). Thickness varies from ~100 m to ~350 m depending on the paleotopography of the basement rocks upon which the sandstone was deposited. The base of the unit contains the highest abundance of conglomerates. Cobbles and pebbles sourced from the underlying basement rocks are common in the basal unit. Grain size and bed thickness thins upwards (Middleton and Elliott, 2003). Common sedimentary structures include planar and trough cross-bedding, which both decrease in thickness up-sequence. Fossils are rare but within the upper part of the sequence, body fossils date to the early Cambrian (Middleton and Elliott, 2003).
    [Show full text]
  • Dolomite: Occurrence, Evolution and Economically Important Associations
    Earth-Science Reviews 52Ž. 2000 1±81 www.elsevier.comrlocaterearscirev Dolomite: occurrence, evolution and economically important associations John Warren Department Petroleum Geosciences, UniÕersity Brunei Darussalam, Tungku Link, Bandar Seri Begawan, Brunei Received 14 October 1999; accepted 7 July 2000 Abstract Dolomite is not a simple mineral; it can form as a primary precipitate, a diagenetic replacement, or as a hydrothermalrmetamorphic phase, all that it requires is permeability, a mechanism that facilitates fluid flow, and a sufficient supply of magnesium. Dolomite can form in lakes, on or beneath the shallow seafloor, in zones of brine reflux, and in early to late burial settings. It may form from seawater, from continental waters, from the mixing of basinal brines, the mixing of hypersaline brine with seawater, or the mixing of seawater with meteoric water, or via the cooling of basinal brines. Bacterial metabolism may aid the process of precipitation in settings where sulfate-reducing species flourish and microbial action may control primary precipitation in some hypersaline anoxic lake settings. Dolomite is a metastable mineral, early formed crystals can be replaced by later more stable phases with such replacements repeated a number of times during burial and metamorphism. Each new phase is formed by the partial or complete dissolution of an earlier dolomite. This continual re-equilibration during burial detracts from the ability of trace elements to indicate depositional conditions and resets the oxygen isotope signature of the dolomite at progressively higher temperatures. Because subsurface dolomite evolves via dissolution and reprecipitation, a bed of dolomite can retain or create porosity and permeability to much greater burial depths and into higher temperature realms than a limestone counterpart.
    [Show full text]
  • Igneous and Metamorphic Reservoirs | by E
    UNICORNS IN THE GARDEN OF GOOD AND EVIL: Part 8 – Igneous and Metamorphic Reservoirs | By E. R. (Ross) Crain, P.Eng. Unicorns are beautiful, mythical beasts, much sought after by us mere mortals. The same is true for petrophysical models for unconventional reservoirs. This is the eighth in a series of review articles outlining the simple beauty of some practical methods for log analysis of the unusual. IGNEOUS AND METAMORPHIC BASICS Igneous and metamorphic rocks form reservoirs in many parts of the world. Reservoir quality varies and most benefit from natural fractures. Although some geologists believe the hydrocarbons in some Figure 1. Eyjafjallajokull volcano, Iceland, 2010. granite reservoirs comes from deep in the earth, the majority of these reservoirs can Igneous rocks are classified in several ways Parent Rock Metamorphic be shown to contain hydrocarbons that – by composition, texture, and method of Equivalent migrated from conventional sedimentary emplacement. Generally speaking, the Sandstone Quartzite sources. composition (mineral mixture) determines Limestone, Dolomite Marble the log response, the texture determines the As a generalization, metamorphic rocks are name used for the mineral mixture, and the Basalt Schist or Amphibolite rocks that have been exposed to high heat method of emplacement determines the Shale Slate and pressure. The main causes are: texture and internal porosity structure (if any). Granite Schist • Contact metamorphism – changes in the rock due to heat from a nearby magma Intrusive igneous rocks are formed inside the Rhyolite Schist source. earth. This type of igneous rock cools very Table 1. Metamorphic rock origins. • Regional metamorphism – changes slowly and is produced by magma from the caused by widespread elevated heat and interior of the earth.
    [Show full text]
  • GRAND CANYON GUIDE No. 6
    GRAND CANYON GUIDE no. 6 ... excerpted from Grand Canyon Explorer … Bob Ribokas AN AMATEUR'S REVIEW OF BACKPACKING TOPICS FOR THE T254 - EXPEDITION TO THE GRAND CANYON - MARCH 2007 Descriptions of Grand Canyon Layers Grand Canyon attracts the attention of the world for many reasons, but perhaps its greatest significance lies in the geologic record that is so beautifully preserved and exposed here. The rocks at Grand Canyon are not inherently unique; similar rocks are found throughout the world. What is unique about the geologic record at Grand Canyon is the great variety of rocks present, the clarity with which they're exposed, and the complex geologic story they tell. Paleozoic Strata: Kaibab depositional environment: Kaibab Limestone - This layer forms the surface of the Kaibab and Coconino Plateaus. It is composed primarily of a sandy limestone with a layer of sandstone below it. In some places sandstone and shale also exists as its upper layer. The color ranges from cream to a greyish-white. When viewed from the rim this layer resembles a bathtub ring and is commonly referred to as the Canyon's bathtub ring. Fossils that can be found in this layer are brachiopods, coral, mollusks, sea lilies, worms and fish teeth. Toroweap depositional environment Toroweap Formation - This layer is composed of pretty much the same material as the Kaibab Limestone above. It is darker in color, ranging from yellow to grey, and contains a similar fossil history. Coconino depositional environment: Coconino Sandstone - This layer is composed of pure quartz sand, which are basically petrified sand dunes. Wedge-shaped cross bedding can be seen where traverse-type dunes have been petrified.
    [Show full text]
  • Grand Canyon
    U.S. Department of the Interior Geologic Investigations Series I–2688 14 Version 1.0 4 U.S. Geological Survey 167.5 1 BIG SPRINGS CORRELATION OF MAP UNITS LIST OF MAP UNITS 4 Pt Ph Pamphlet accompanies map .5 Ph SURFICIAL DEPOSITS Pk SURFICIAL DEPOSITS SUPAI MONOCLINE Pk Qr Holocene Qr Colorado River gravel deposits (Holocene) Qsb FAULT CRAZY JUG Pt Qtg Qa Qt Ql Pk Pt Ph MONOCLINE MONOCLINE 18 QUATERNARY Geologic Map of the Pleistocene Qtg Terrace gravel deposits (Holocene and Pleistocene) Pc Pk Pe 103.5 14 Qa Alluvial deposits (Holocene and Pleistocene) Pt Pc VOLCANIC ROCKS 45.5 SINYALA Qti Qi TAPEATS FAULT 7 Qhp Qsp Qt Travertine deposits (Holocene and Pleistocene) Grand Canyon ၧ DE MOTTE FAULT Pc Qtp M u Pt Pleistocene QUATERNARY Pc Qp Pe Qtb Qhb Qsb Ql Landslide deposits (Holocene and Pleistocene) Qsb 1 Qhp Ph 7 BIG SPRINGS FAULT ′ × ′ 2 VOLCANIC DEPOSITS Dtb Pk PALEOZOIC SEDIMENTARY ROCKS 30 60 Quadrangle, Mr Pc 61 Quaternary basalts (Pleistocene) Unconformity Qsp 49 Pk 6 MUAV FAULT Qhb Pt Lower Tuckup Canyon Basalt (Pleistocene) ၣm TRIASSIC 12 Triassic Qsb Ph Pk Mr Qti Intrusive dikes Coconino and Mohave Counties, Pe 4.5 7 Unconformity 2 3 Pc Qtp Pyroclastic deposits Mr 0.5 1.5 Mၧu EAST KAIBAB MONOCLINE Pk 24.5 Ph 1 222 Qtb Basalt flow Northwestern Arizona FISHTAIL FAULT 1.5 Pt Unconformity Dtb Pc Basalt of Hancock Knolls (Pleistocene) Pe Pe Mၧu Mr Pc Pk Pk Pk NOBLE Pt Qhp Qhb 1 Mၧu Pyroclastic deposits Qhp 5 Pe Pt FAULT Pc Ms 12 Pc 12 10.5 Lower Qhb Basalt flows 1 9 1 0.5 PERMIAN By George H.
    [Show full text]