Pedogenic Features of the Chinle Group, Four Corners Region: Evidence of Late Triassic Aridification Lawrence H

Total Page:16

File Type:pdf, Size:1020Kb

Pedogenic Features of the Chinle Group, Four Corners Region: Evidence of Late Triassic Aridification Lawrence H New Mexico Geological Society Downloaded from: http://nmgs.nmt.edu/publications/guidebooks/54 Pedogenic features of the Chinle Group, Four Corners region: Evidence of Late Triassic aridification Lawrence H. Tanner, 2003, pp. 269-280 in: Geology of the Zuni Plateau, Lucas, Spencer G.; Semken, Steven C.; Berglof, William; Ulmer-Scholle, Dana; [eds.], New Mexico Geological Society 54th Annual Fall Field Conference Guidebook, 425 p. This is one of many related papers that were included in the 2003 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. No material from the NMGS website, or printed and electronic publications, may be reprinted or redistributed without NMGS permission. Contact us for permission to reprint portions of any of our publications. One printed copy of any materials from the NMGS website or our print and electronic publications may be made for individual use without our permission. Teachers and students may make unlimited copies for educational use. Any other use of these materials requires explicit permission. This page is intentionally left blank to maintain order of facing pages. New Mexico Geological Society Guidebook, 54th Field Conference, Geology of the Zuni Plateau, 2003, p. 269-280. 269 PEDOGENIC FEATURES OF THE CHINLE GROUP, FOUR CORNERS REGION: EVIDENCE OF LATE TRIASSIC ARIDIFICATION LAWRENCE H. TANNER Department of Geography and Geosciences, Bloomsburg University, Bloomsburg, PA 17815 ABSTRACT.—Paleosols and pedogenic features in formations of the Upper Triassic Chinle Group preserve a record of changing paleoclimate in the Four Corners region. The Carnian mottled strata and Shinarump formations contain strongly gleyed and bioturbated paleosols with a prismatic fabric that formed under the infl uence of a subhumid but (likely) strongly seasonal climate. Thick argillic horizons with epipedons in the overlying Cameron Formation and the Blue Mesa Member of the Petrifi ed Forest Formation, and the prominence of vertic features and calcrete horizons in the Blue Mesa and Painted Desert members suggest that the climate became less humid, but remained strongly seasonal, from late Carnian through early Norian time. Mature calcrete profi les in the middle Norian Owl Rock Formation document continued aridifi ca- tion leading to semiarid conditions. Strata of the Rhaetian Rock Point Formation contain few paleosols other than immature calcretes, but the abundance of eolian and playa facies in this formation suggest increasing aridity through the end of the Triassic. Interformational variations in the carbon-isotope composition of pedogenic carbonate are consistent with this trend of aridifi cation at a time of elevated atmospheric CO2. Although not world-wide, aridifi cation was widespread across Pangea, and possibly resulted from the increasing strength of monsoonal fl ow and the weakening of zonal circulation, particularly at lower latitudes, as the continent drifted northward. INTRODUCTION source areas for these sediments included the Mogollon high- lands, located approximately 500 km to the south and southwest, The spatial and temporal resolution of paleoclimate models the Uncompahgre highlands located 200 to 300 km to the east has improved dramatically since the interpretations of Robinson and northeast (Blakey and Gubitosa, 1983; Marzolf, 1994), and (1973), in part through the increasing use of paleosols and pedo- more distant upland areas in Texas (McGowan et al., 1983; Riggs genic features as paleoclimate archives. Indeed, the morphology et al., 1996). Across most of the Colorado Plateau, lowermost and composition of paleosols have long been used to ascertain past Chinle strata were deposited unconformably on Moenkopi Group climate conditions (see Kraus, 1999 for a review). Although com- and older strata (the Tr-3 unconformity) following an interval of paction, erosion, and diagenetic alteration of paleosols may render lowered base-level and incision. The Shinarump and Cameron precise interpretation of the conditions of paleosol formation formations, and Blue Mesa Member of the Petrifi ed Forest For- problematic, many climate-dependent pedogenic features, such as mation, and lateral equivalents, were deposited during late Car- calcrete horizons, gleying, and translocation of clay and sesquiox- nian on this incised surface (Lucas, 1993; Lucas et al., 1997). The ides, have high preservation potential, rendering paleosols a valu- Tr-4 unconformity separates the Sonsela Member of the Petrifi ed able record of paleoclimate. The geochemistry of paleosols, in Forest Formation and the laterally equivalent Moss Back Forma- particular, the stable isotope composition of calcareous nodules in tion from the underlying Blue Mesa strata (Heckert and Lucas, calcretes, has been shown to be useful for the analysis of paleocli- 1996, 2002; Lucas et al., 1997). The Owl Rock Formation was mate and atmospheric composition (Cerling, 1991, 1999; Driese deposited conformably to locally unconformably on the Painted et al., 1992; Driese and Mora, 1993; Caudill et al., 1996; Liu et al., Desert Member of the Petrifi ed Forest Formation during the δ13 1996). The estimation of atmospheric paleo-p(CO2) using C of middle Norian time. The Rhaetian Rock Point Formation uncon- pedogenic carbonate and the diffusion-reaction model developed formably overlies the Owl Rock Formation (Tr-5 unconformity) by Cerling (1991) is now widely considered reliable because and grades vertically to the mainly Hettangian Wingate Forma- values of δ13C do not appear susceptible to diagenetic modifi ca- tion. Previous studies have established the details of the stratigra- tion (Cerling, 1991; Driese and Mora, 1993; Mora et al., 1996), phy and architectural elements of these formations (Stewart et al., and calculated paleo-p(CO2) levels compare favorably with values 1972; Blakey and Gubitosa, 1983; Kraus and Middleton, 1987; from geochemical modeling (Berner, 1993). Dubiel, 1987; Lucas, 1993; Lucas et al., 1997; Tanner, 2000). Geologic Setting and Stratigraphy PEDOGENIC FEATURES OF CHINLE GROUP STRATA The Four Corners region was located at near-equatorial lati- Paleosols have long been recognized as prominent components tudes (less than 10o N) during Late Triassic time (Scotese, 1994; of the Chinle Group formations, and general features of these Molina-Garza et al., 1995; Kent and Olsen, 1997). Late Carnian paleosols have been cited in previous interpretations of Triassic to Rhaetian strata of the Chinle Group, now exposed across much paleoclimate (Dubiel, 1987; Dubiel et al., 1991; Parrish, 1993). of the Colorado Plateau (Fig. 1), were deposited in a continental Yet few studies have examined the pedogenic features and asso- back-arc basin that extended from southwestern Texas to north- ciated climatic implications in substantial detail. Most existing ern Wyoming (Lucas, 1993; Lucas et al., 1997; Lucas, 1999). descriptions have focused on individual formations (Blodgett, Deposition within the Chinle basin was controlled primarily 1988; Lucas and Anderson, 1993; Tanner, 2000; Therrien and by streams fl owing northwest across a broad alluvial plain. The Fastovsky, 2000), or are cursory summaries of the features of the 270 TANNER Field Example: Mottled Strata Near Fort Wingate, New Mexico, over 20 m of strongly mottled mudstone and sandstone beds rest unconformably on strata of the Moenkopi Group (see Stop 1, Day 2 in Roadlogs, this volume; also Lucas and Hayden, 1989). The stratigraphic position of these strata below the coarse sandstones and conglomerates of the Shinarump Formation indicates that they belong to the mottled strata. Pedogenic modifi cation, consisting of some combination of gleying (color mottling), desiccation, or root traces or casts, is evident in all of the strata in the sequence. Mudstone beds are up to 1.5 thick and typically display a crudely prismatic fabric and medium bluish gray (5B 5/1) to light yellowish gray (5Y 8/1) gley mottling in a host that varies from dark reddish brown (10R 3/4) to dark yellow orange (10YR 6/6) (Fig. 2A). Locally, the gley mottling follows a coarse reticulate pattern. Through most of the sequence, the beds are penetrated by near-vertical sandstone cylinders, some up to 1.5 m long. These have a nearly straight
Recommended publications
  • Geologic Studies of Union County, New Mexico
    Bulletin 63 New Mexico Bureau of Mines & Mineral Resources A DIVISION OF NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY Geologic Studies of Union County, New Mexico by Brewster Baldwin and William R. Muehlberger SOCORRO 1959 NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY KENNETH W. FORD, President NEW MEXICO BUREAU OF MINES & MINERAL RESOURCES FRANK E. KOTTLOWSKI, Director GEORGE S. Austin, Deputy Director BOARD OF REGENTS Ex Officio Bruce King, Governor of New Mexico Leonard DeLayo, Superintendent of Public Instruction Appointed William G. Abbott, Secretary-Treasurer, 1961-1985, Hobbs Judy Floyd, President, 1977-1981, Las Cruces Owen Lopez, 1977-1983, Santa Fe Dave Rice, 1972-1983, Carlsbad Steve Torres, 1967-1985, Socorro BUREAU STAFF Full Time MARLA D. ADKINS, Assistant Editor LYNNE MCNEIL, Staff Secretary ORIN J. ANDERSON, Geologist NORMA J. MEEKS, Department Secretary RUBEN ARCHULETA, Technician I ARLEEN MONTOYA, Librarian/Typist WILLIAM E. ARNOLD, Scientific Illustrator SUE NESS, Receptionist ROBERT A. BIEBERMAN, Senior Petrol. Geologist ROBERT M. NORTH, Mineralogist LYNN A. BRANDVOLD, Chemist JOANNE C. OSBURN, Geologist CORALE BRIEBLEY, Chemical Microbiologist GLENN R. OSBURN, Volcanologist BRENDA R. BROADWELL, Assoc. Lab Geoscientist LINDA PADILLA, Staff Secretary FRANK CAMPBELL, Coal Geologist JOAN C. PENDLETON, Associate Editor RICHARD CHAMBERLIN, Economic Geologist JUDY PERALTA, Executive Secretary CHARLES E. CHAPIN, Senior Geologist BARBARA R. Popp, Lab. Biotechnologist JEANETTE CHAVEZ, Admin. Secretary I ROBERT QUICK, Driller's Helper/Driller RICHARD R. CHAVEZ, Assistant Head, Petroleum MARSHALL A. REITER, Senior Geophyicist RUBEN A. CRESPIN, Laboratory Technician II JACQUES R. RENAULT, Senior Geologist Lois M. DEVLIN, Director, Bus.-Pub. Office JAMES M. ROBERTSON, Mining Geologist KATHY C. EDEN, Editorial Technician GRETCHEN H.
    [Show full text]
  • Tetrapod Biostratigraphy and Biochronology of the Triassic–Jurassic Transition on the Southern Colorado Plateau, USA
    Palaeogeography, Palaeoclimatology, Palaeoecology 244 (2007) 242–256 www.elsevier.com/locate/palaeo Tetrapod biostratigraphy and biochronology of the Triassic–Jurassic transition on the southern Colorado Plateau, USA Spencer G. Lucas a,⁎, Lawrence H. Tanner b a New Mexico Museum of Natural History, 1801 Mountain Rd. N.W., Albuquerque, NM 87104-1375, USA b Department of Biology, Le Moyne College, 1419 Salt Springs Road, Syracuse, NY 13214, USA Received 15 March 2006; accepted 20 June 2006 Abstract Nonmarine fluvial, eolian and lacustrine strata of the Chinle and Glen Canyon groups on the southern Colorado Plateau preserve tetrapod body fossils and footprints that are one of the world's most extensive tetrapod fossil records across the Triassic– Jurassic boundary. We organize these tetrapod fossils into five, time-successive biostratigraphic assemblages (in ascending order, Owl Rock, Rock Point, Dinosaur Canyon, Whitmore Point and Kayenta) that we assign to the (ascending order) Revueltian, Apachean, Wassonian and Dawan land-vertebrate faunachrons (LVF). In doing so, we redefine the Wassonian and the Dawan LVFs. The Apachean–Wassonian boundary approximates the Triassic–Jurassic boundary. This tetrapod biostratigraphy and biochronology of the Triassic–Jurassic transition on the southern Colorado Plateau confirms that crurotarsan extinction closely corresponds to the end of the Triassic, and that a dramatic increase in dinosaur diversity, abundance and body size preceded the end of the Triassic. © 2006 Elsevier B.V. All rights reserved. Keywords: Triassic–Jurassic boundary; Colorado Plateau; Chinle Group; Glen Canyon Group; Tetrapod 1. Introduction 190 Ma. On the southern Colorado Plateau, the Triassic– Jurassic transition was a time of significant changes in the The Four Corners (common boundary of Utah, composition of the terrestrial vertebrate (tetrapod) fauna.
    [Show full text]
  • Triassic Stratigraphy of the Southeastern Colorado Plateau, West-Central New Mexico Spencer G
    New Mexico Geological Society Downloaded from: https://nmgs.nmt.edu/publications/guidebooks/72 Triassic stratigraphy of the southeastern Colorado Plateau, west-central New Mexico Spencer G. Lucas, 2021, pp. 229-240 in: Geology of the Mount Taylor area, Frey, Bonnie A.; Kelley, Shari A.; Zeigler, Kate E.; McLemore, Virginia T.; Goff, Fraser; Ulmer-Scholle, Dana S., New Mexico Geological Society 72nd Annual Fall Field Conference Guidebook, 310 p. This is one of many related papers that were included in the 2021 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. 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, Color Plates, 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]
  • A Re-Evaluation of the Enigmatic Dinosauriform Caseosaurus Crosbyensis from the Late Triassic of Texas, USA and Its Implications for Early Dinosaur Evolution
    A re-evaluation of the enigmatic dinosauriform Caseosaurus crosbyensis from the Late Triassic of Texas, USA and its implications for early dinosaur evolution MATTHEW G. BARON and MEGAN E. WILLIAMS Baron, M.G. and Williams, M.E. 2018. A re-evaluation of the enigmatic dinosauriform Caseosaurus crosbyensis from the Late Triassic of Texas, USA and its implications for early dinosaur evolution. Acta Palaeontologica Polonica 63 (1): 129–145. The holotype specimen of the Late Triassic dinosauriform Caseosaurus crosbyensis is redescribed and evaluated phylogenetically for the first time, providing new anatomical information and data on the earliest dinosaurs and their evolution within the dinosauromorph lineage. Historically, Caseosaurus crosbyensis has been considered to represent an early saurischian dinosaur, and often a herrerasaur. More recent work on Triassic dinosaurs has cast doubt over its supposed dinosaurian affinities and uncertainty about particular features in the holotype and only known specimen has led to the species being regarded as a dinosauriform of indeterminate position. Here, we present a new diagnosis for Caseosaurus crosbyensis and refer additional material to the taxon—a partial right ilium from Snyder Quarry. Our com- parisons and phylogenetic analyses suggest that Caseosaurus crosbyensis belongs in a clade with herrerasaurs and that this clade is the sister taxon of Dinosauria, rather than positioned within it. This result, along with other recent analyses of early dinosaurs, pulls apart what remains of the “traditional” group of dinosaurs collectively termed saurischians into a polyphyletic assemblage and implies that Dinosauria should be regarded as composed exclusively of Ornithoscelida (Ornithischia + Theropoda) and Sauropodomorpha. In addition, our analysis recovers the enigmatic European taxon Saltopus elginensis among herrerasaurs for the first time.
    [Show full text]
  • Palynology of the Upper Chinle Formation in Northern New Mexico, U.S.A
    Lindström et al. 1 1 Palynology of the upper Chinle Formation in northern New Mexico, U.S.A.: 2 implications for biostratigraphy and terrestrial ecosystem change during the Late 3 Triassic (Norian–Rhaetian) 4 a* b c d 5 Sofie Lindström , Randall B. Irmis , Jessica H. Whiteside , Nathan D. Smith , Sterling J. e f 6 Nesbitt , and Alan H. Turner 7 a 8 Geological Survey of Denmark and Greenland, Øster Voldgade 10, DK-1350 Copenhagen 9 K, DENMARK, [email protected] b 10 Natural History Museum of Utah and Department of Geology & Geophysics, University of 11 Utah, Salt Lake City, UT 84108-1214, USA c 12 Ocean and Earth Science, National Oceanography Centre Southampton, University of 13 Southampton, European Way, Southampton SO14 3ZH, UNITED KINGDOM d 14 Dinosaur Institute, Natural History Museum of Los Angeles County, Los Angeles, CA 15 90007, USA e 16 Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, 17 Virginia 24601 USA f 18 Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York 19 11794-8081, USA 20 21 Abstract 22 A new densely sampled palynological record from the vertebrate-bearing upper Chinle 23 Formation at Ghost Ranch in the Chama Basin of northwestern New Mexico provides insights 24 into the biostratigraphy and terrestrial ecosystem changes during the Late Triassic of 25 northwestern Pangaea. Spore-pollen assemblages from the Poleo Sandstone, Petrified Forest, Lindström et al. 2 26 and 'siltstone' members are dominated by pollen of corystospermous seed ferns (Alisporites) 27 and voltziacean conifers (Enzonalasporites, Patinasporites). Other abundant taxa include 28 Klausipollenites gouldii and the enigmatic fused tetrad Froelichsporites traversei, whereas 29 spores of ferns and fern allies are generally rare.
    [Show full text]
  • Bulletin No. 6
    Bulletin no. 6 Dr. Robert D. McCord and Debra Boaz, eds. Bulletin number 6 was produced as a companion to the 1999 Southwest Paleontological Symposium hosted by the Mesa Southwest Museum and the Southwest Paleontological Society (SPS). The volume is a collection of papers and descriptive abstracts of the presentations given by professional scientists, students, and avocationists. The subject matter is broad, reflecting the abundance of paleontological resources in the southwestern region. 60 pages. Southwest Paleontological Symposium Proceedings Mesa Southwest Museum Bulletin No. 6 Table of Contents Enigmatic Structures in the Apache Group, 1.2 GA., North‐Central Arizona (abstract) John McClellan and Carol M. Tang Department of Geology Arizona State University Skolithos Piperock in the Bolsa Quartzite (Cambrian), Whetstone Mountains, Arizona (abstract) Carol M. Tang Department of Geology Arizona State University Description of Two Coral Species in the Devonian Martin Formation (Kohl's Ranch, Arizona) (abstract) Lisa Glonek and Carol M. Tang Department of Geology Arizona State University Brachiopod Variation Within the Lower Pennsylvanian Naco Formation, Tonto Creek, Central Arizona (abstract) E.M. Young and Carol M. Tang Department of Geology Arizona State University Lower Chinle Group (Upper Triassic: Upper Carnian) Tetrapods from the Vicinity of Cameron, Arizona (abstract) A. B. Heckert Department of Earth & Planetary Science University of New Mexico S. G. Lucas and J. W. Estep New Mexico Museum of Natural History and Science Additions to the Vertebrate Fauna of the Upper Triassic Blue Mesa Member (Adamanian‐Latest Carnian) of the Petrified Forest Formation in the Blue Hills, Apache County, Arizona (abstract) A. B. Heckert Department of Earth & Planetary Science University of New Mexico S.
    [Show full text]
  • Mesozoic Stratigraphy at Durango, Colorado
    160 New Mexico Geological Society, 56th Field Conference Guidebook, Geology of the Chama Basin, 2005, p. 160-169. LUCAS AND HECKERT MESOZOIC STRATIGRAPHY AT DURANGO, COLORADO SPENCER G. LUCAS AND ANDREW B. HECKERT New Mexico Museum of Natural History and Science, 1801 Mountain Rd. NW, Albuquerque, NM 87104 ABSTRACT.—A nearly 3-km-thick section of Mesozoic sedimentary rocks is exposed at Durango, Colorado. This section con- sists of Upper Triassic, Middle-Upper Jurassic and Cretaceous strata that well record the geological history of southwestern Colorado during much of the Mesozoic. At Durango, Upper Triassic strata of the Chinle Group are ~ 300 m of red beds deposited in mostly fluvial paleoenvironments. Overlying Middle-Upper Jurassic strata of the San Rafael Group are ~ 300 m thick and consist of eolian sandstone, salina limestone and siltstone/sandstone deposited on an arid coastal plain. The Upper Jurassic Morrison Formation is ~ 187 m thick and consists of sandstone and mudstone deposited in fluvial environments. The only Lower Cretaceous strata at Durango are fluvial sandstone and conglomerate of the Burro Canyon Formation. Most of the overlying Upper Cretaceous section (Dakota, Mancos, Mesaverde, Lewis, Fruitland and Kirtland units) represents deposition in and along the western margin of the Western Interior seaway during Cenomanian-Campanian time. Volcaniclastic strata of the overlying McDermott Formation are the youngest Mesozoic strata at Durango. INTRODUCTION Durango, Colorado, sits in the Animas River Valley on the northern flank of the San Juan Basin and in the southern foothills of the San Juan and La Plata Mountains. Beginning at the northern end of the city, and extending to the southern end of town (from north of Animas City Mountain to just south of Smelter Moun- tain), the Animas River cuts in an essentially downdip direction through a homoclinal Mesozoic section of sedimentary rocks about 3 km thick (Figs.
    [Show full text]
  • Magnetostratigraphy of the Upper Triassic Chinle Group of New Mexico: Implications for Regional and Global Correlations Among Upper Triassic Sequences
    Magnetostratigraphy of the Upper Triassic Chinle Group of New Mexico: Implications for regional and global correlations among Upper Triassic sequences Kate E. Zeigler1,* and John W. Geissman2,* 1Department of Earth and Planetary Sciences, MSC 03-2040 Northrop Hall, University of New Mexico, Albuquerque, New Mexico 87131, USA 2Department of Earth and Planetary Sciences, MSC 03-2040 Northrop Hall, University of New Mexico, Albuquerque, New Mexico 87131, USA, and Department of Geosciences, ROC 21, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080-3021, USA ABSTRACT polarity chronologies from upper Chinle graphic correlations (e.g., Reeve, 1975; Reeve and strata in New Mexico and Utah suggest that Helsley, 1972; Bazard and Butler, 1989, 1991; A magnetic polarity zonation for the strata considered to be part of the Rock Point Molina-Garza et al., 1991, 1993, 1996, 1998a, Upper Triassic Chinle Group in the Chama Formation in north-central New Mexico are 1998b, 2003; Steiner and Lucas, 2000). Conse- Basin, north-central New Mexico (United not time equivalent to type Rock Point strata quently, the polarity record of the mudstones and States), supplemented by polarity data from in Utah or to the Redonda Formation of east- claystones, which are the principal rock types in eastern and west-central New Mexico (Mesa ern New Mexico. the Chinle Group, is largely unknown. Redonda and Zuni Mountains, respectively), In our study of Triassic strata in the Chama provides the most complete and continuous INTRODUCTION Basin of north-central New Mexico, we sam- magnetic polarity chronology for the Late pled all components of the Chinle Group, with Triassic of the American Southwest yet avail- The Upper Triassic Chinle Group, prominent a focus on mudstones and claystones at Coyote able.
    [Show full text]
  • The Geology of Quail Creek State Park Itself, the Park Is Surrounded by a Landscape of Enormous Geological and Human Interest
    TT HH EE G E O L OO GG Y OO FF Q UU AA II LL C R E E K SS T A TT EE PP A R K T H E G E O L O G Y O F Q U A I L C R E E K S T A T E P A R K T H E GEOLO G Y O F Q UA IL CREEK STAT E PA R K by Robert F. Biek Introduction . 1 Layers of Rock. 3 Regional overview . 3 Moenkopi Formation . 4 Shnabkaib Member . 6 Upper red member . 7 Chinle Formation . 7 Shinarump Conglomerate Member . 7 Petrified Forest Member . 8 Surficial deposits . 9 Talus deposits . 9 Mixed river and slopewash deposits . 9 Landslides. 9 The Big Picture . 10 Geological Highlights . .14 Virgin anticline . .14 Faults . .14 Gypsum . .14 “Picture stone” . .15 Boulders from the Pine Valley Mountains . .16 Catastrophic failure of the Quail Creek south dike . .17 Acknowledgments . .19 References . .19 T H E G E O L O G Y O F Q U A I L C R E E K S T A T E P A R K I N T R O D U C T I O N The first thing most visitors to Quail Creek State Park notice, apart from the improbably blue and refreshing waters of the reservoir itself, are the brightly colored, layered rocks of the surrounding cliffs. In fact, Quail Creek State Park lies astride one of the most remarkable geologic features in southwest- ern Utah. The park lies cradled in the eroded core of the Virgin anticline, a long upwarp of folded rock that trends northeast through south-central Washington County.
    [Show full text]
  • Earliest Jurassic U-Pb Ages from Carbonate Deposits in the Navajo Sandstone, Southeastern Utah, USA Judith Totman Parrish1*, E
    https://doi.org/10.1130/G46338.1 Manuscript received 3 April 2019 Revised manuscript received 10 July 2019 Manuscript accepted 11 August 2019 © 2019 The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license. Published online 4 September 2019 Earliest Jurassic U-Pb ages from carbonate deposits in the Navajo Sandstone, southeastern Utah, USA Judith Totman Parrish1*, E. Troy Rasbury2, Marjorie A. Chan3 and Stephen T. Hasiotis4 1 Department of Geological Sciences, University of Idaho, P.O. Box 443022, Moscow, Idaho 83844, USA 2 Department of Geosciences, Stony Brook University, Stony Brook, New York 11794, USA 3 Department of Geology and Geophysics, University of Utah, 115 S 1460 E, Room 383, Salt Lake City, Utah 84112-0102, USA 4 Department of Geology, University of Kansas, 115 Lindley Hall, 1475 Jayhawk Boulevard, Lawrence, Kansas 66045-7594, USA ABSTRACT with the lower part of the Navajo Sandstone New uranium-lead (U-Pb) analyses of carbonate deposits in the Navajo Sandstone in across a broad region from southwestern Utah southeastern Utah (USA) yielded dates of 200.5 ± 1.5 Ma (earliest Jurassic, Hettangian Age) to northeastern Arizona (Blakey, 1989; Hassan and 195.0 ± 7.7 Ma (Early Jurassic, Sinemurian Age). These radioisotopic ages—the first re- et al., 2018). The Glen Canyon Group is under- ported from the Navajo erg and the oldest ages reported for this formation—are critical for lain by the Upper Triassic Chinle Formation, understanding Colorado Plateau stratigraphy because they demonstrate that initial Navajo which includes the Black Ledge sandstone (e.g., Sandstone deposition began just after the Triassic and that the base of the unit is strongly Blakey, 2008; Fig.
    [Show full text]
  • Bibliography of Arizona Vertebrate Paleontology
    Heckert, A.B., and Lucas, S.G., eds., 2005, Vertebrate Paleontology in Arizona. New Mexico Museum of Natural History and Science Bulletin No. 29. 168 BIBLIOGRAPHY OF ARIZONA VERTEBRATE PALEONTOLOGY CALEB LEWIS1, ANDREW B. HECKERT2 and SPENCER G. LUCAS1 1New Mexico Museum of Natural History and Science, 1801 Mountain Road NW, Albuquerque, NM 87104-1375; 2Department of Geology, Appalachian State University, ASU Box 32067, Boone, NC 28608-2067 Abstract—We provide a bibliography of Arizona vertebrate paleontology that consits of approximately 625 references covering vertebrate occurrences ranging in age from Devonian to Holocene. Not surpris- ingly, references to Triassic and Neogene vertebrates are the most numerous, reflecting the particular strengths of the Arizona record. We break the bibliography down into various taxic groups and provide a complete, unified bibliography at the end of the paper. Keyworks: Arizona, bibliography, fossil, vertebrate, paleontology INTRODUCTION tracks from the Paleozoic and Mesozoic of the state. The Lower Permian Coconino and Lower Jurassic Navajo sandstones in Our aim in presenting a bibliography of Arizona vertebrate northern Arizona are especially known for their vertebrate and paleontology is to provide a valuable research tool for all those invertebrate trackways. conducting vertebrate paleontology research in Arizona. This Abstracts were generally omitted from the bibliography bibliography will also be made available as individual, download - partly to save space, but also due to the difficulty in tracking able Endnote® libraries on the New Mexico Museum of Natural down all published abstracts, many of which exist only in the History and Science paleontological resources website (www. “gray literature” and are duplicated by subsequent full-length nmfossils.org).
    [Show full text]
  • Distribution and Significance of Mesozoic Vertebrate Trace Fossil
    Lockley et al.: Distribution and Significance of Mesozoic Vertebrate Trace Fossil DISTRIBUTION AND SIGNIFICANCE OF MESOZOIC VERTEBRATE TRACE FOSSILS IN DINOSAUR NATIONAL MONUMENT • MARTIN LOCKLEY +KELLY CONRAD +MARC PAQUETTE GEOLOGY DEPARTMENT + UNIVERSITY OF COLORADO DENVER • INTRODUCTION • - FIELD METHODS Dinosaur National Monument (DNM) During the summer of 1991 (end of year one encompasses a large area with surface exposures of and start of year two), reconaissance exploration for. Mesozoic rocks. Although only one isolated footprint vertebrate tracks at DNM was undertaken by Martin (from an unknown locality) had previously been Lockley, Kelly Conrad and Mark Paquette in June, discovered at DNM, there is a high potential for July and August. Following our initial success with preservation of fossil footprints in this area, as has tracksite discovery in the late Triassic Chinle/Popo been proven by discoveries in similar rocks in the Agie beds of the western part of DNM, we continued -region around DNM, and during research activity at to survey this unit throughout DNM. Tracks were DNM. As reported by Lockley et al. (1990), the found at all but the last locality. At all sites where purpose of this research is to seek, document and exposure permitted, we also measured the interpret vertebrate trace fossils in any of the ten stratigraphic position of trackbearing layers. potentially track-bearing Mesozoic stratigraphic units in which footprints might be discovered. We also began a collecting and replicating program that resulted in the acquisition of 27 original During the course of the first ·year (6/90-6/91) specimens · and replicas. Tracks were molded from the University of Colorado at Denver Research Group original specimens in the field using latex rubber, documented 11 localities where tracks were then replicated in the lab using plaster of Paris.
    [Show full text]