DOCSLIB.ORG

Type Section of the Beacon Sandstone of Antarctica

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Type Section of the Beacon Sandstone of Antarctica CD Type Section of the 1C PHI 3 Beacon Sandstone of Antarctica GEOLOGICAL SURVEY PROFESSIONAL PAPER 456-A Prepared on behalf of the National Science Foundation CQ g ^ CQ PQ EH CQ Type Section of the Beacon Sandstone of Antarctica By WARREN HAMILTON and PHILIP T. HAYES CONTRIBUTIONS TO THE GEOLOGY OF ANTARCTICA GEOLOGICAL SURVEY PROFESSIONAL PAPER 456-A Prepared on behalf of the National Science Foundation 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, D.C., 20402 CONTENTS Page Diabase sheets Continued Page Abstract_____-____________________________________ Al Petrology__-___________________________________ A12 Introduction_______________ _ ______________________ 1 Metamorphism of the Beacon Sandstone___________ 12 Type section_______________________________________ 4 Age of diabase-__-__----------___-__--_-___---__ 12 Lower part-___________________________________ 4 Age of the Beacon Sandstone_____-_-----__-__-_______ 12 Middle part.___________________________________ 6 Fossils near type section_____-___________________ 12 Upper part---------------_____-----_-___-_-___- 7 Fossils from the Beacon Sandstone of other areas. __ 14 Correlations between sections------_____-____-___- Age of rocks beneath the Beacon Sandstone ________ 14 Nomenclature._____________________________________ Age of the Beacon Sandstane_-__--___--__-_______ 14 Past nomenclature._____________________________ Conditions of deposition___----______________________ 16 Proposed nomenclature and stratigraphic summary- 9 Crossbedding_ __________________________________ 16 Diabase sheets. ____________________________________ 12 Paleoclimate_ __________________________________ 17 Form________________________________________ 12 References cited_____-_--_._.-_-______.____________ 17 ILLUSTRATIONS Page FIGURE 1. Index map of Antarctica_________________________ Al 2. Index map of west coast of McMurdo Sound_________ 2 3. Geologic map of Beacon Heights__________________ 3 4. New Mountain from the north_____________________ 4 5. Columnar sections of Beacon Sandstone _____________ 5 6. West Beacon Heights from the northeast-___________ 6 7. West wall of Beacon Dry Valley___-_-__________--__ 8 8. West part of Finger Mountain from the north_______. 9 9. Pyramid Mountain from the northeast ______________ 10 10. East end of Finger Mountain from the south_________ 11 11. Molds of burrows.-_-___--____-____-___-_-_______- 13 12. Outcrop of upper part of sandstone of New Mountain- 15 13. Crossbedded strata----__-_____-------_____-__--_- 16 ni CONTRIBUTIONS TO THE GEOLOGY OF ANTARCTICA TYPE SECTION OF THE BEACON SANDSTONE OF ANTARCTICA By WARREN HAMILTON and PHILIP T. HATES ABSTRACT "Gondwana" landmasses of Australia, India, South The Beacon Sandstone of Carboniferous(?), Permian, and Africa (Karroo System), and South America. early Mesozoic(?) age is widely distributed in East Antarctica. The formation was named by Ferrar in 1907 for exposures The Beacon Sandstone was named by Ferrar (1907) in Beacon Heights, near Taylor Glacier west of McMurdo Sound, for exposures on West Beacon Heights on the south but no type section has previously been described. This paper side of upper Taylor Glacier (figs. 2 and 3), South presents a composite section in the type area, assembled from Victoria Land. He estimated that about 2,500 feet of a published description of the basal strata by Zeller and others sandstone are present there but did not describe a type (1961), a previously unpublished description of the middle part by the present authors, and a published description of the section. McKelvey and Webb (1959) presented a de­ upper part by McKelvey and Webb (1959). tailed section of the upper part of the formation in the The Beacon Sandstone in its type area consists largely of type area, and Zeller and others (1961) described the light-colored medium- to coarse-grained sandstone, much of it basal part. These partial sections are here tied to the crossbedded. Beds of fine-grained sandstone and siltstone are section studied by us in the middle part of the forma­ subordinate. 1 Carbonaceous strata bearing constituents of the Glossopteris flora occur high in the formation. The middle tion on West Beacon Heights to give, for the first time, part of the formation consists of cliff-forming sandstone, easily a reasonably accurate type section of the Beacon Sand­ recognizable throughout the region, and is separated from the stone. ledge-forming section beneath by a disconformity. Total thick­ The Ross Sea coast of East Antarctica is bounded by a ness of the Beacon is about 4,000 feet. Intrusive into the range of high mountains, which forms a dam against the Beacon are huge sills and inclined sheets of quartz diabase (the Ferrar Dolerites) of Mesozoic age, which have an aggre­ vast inland ice plateau. Valley outlet glaciers, one of gate thickness of about the same amount. The three major units of the Beacon Sandstone in its type area are here referred to as the sandstone of New Mountain (the lower ledge-forming unit), the sandstone of Pyramid Mountain (the middle cliff-forming unit), and the sandstone of Finger Mountain (the upper ledge-forming fossiliferous unit). A thin sequence of diverse rocks, described by Zeller and others (1961), beneath the sandstone of New Mountain may not prop­ erly belong to the Beacon Sandstone. Although several authors have proposed recently that the Beacon be elevated to group status, they have not established mappable formations within the Beacon; consequently, their proposals are premature. Because geologic fieldwork is' likely to be of reconnaissance character and in widely separated areas for some time to come, it seems preferable for the present to maintain formation status for the Beacon Sandstone and to subdivide it into local formal members only when the utility of these is demonstrated by detailed work. INTRODUCTION The Beacon Sandstone of Carboniferous(?), Per­ mian, and early Mesozoic( ?) age forms a discontinuous cover upon much of East Antarctica, the large part of the continent lying mainly in east longitudes (fig. 1). FIGURE 1. Index map of Antarctica. Asterisk indicates location of The sandstone carries a Glossopteris flora and shares Beacon Sandstone type locality. Localities mentioned in text are many features with correlative rocks of the other Priestley Glacier, P; Mount Gran, M; Beardmore Glacier, B ; Mount Weaver, W; Horlick Mountains, H; and Amery locality, A. Al A2 CONTRIBUTIONS TO THE GEOLOGY OF ANTARCTICA 160" 161* 162" 163* 164° 165° 78° 10 MILES 20 KILOMETERS FIGURE 2. Index map of mountains west of McMurdo Sound. Hatched line outlines area of geologic map (fig. 3). which is Taylor Glacier, flow across these mountains which we were flown by a U.S. Navy ski-equipped air­ from the plateau toward the sea through the major plane, as part of our study of the Taylor Glacier-Taylor transverse valleys. Pre-Devonian granitic and meta- Dry Valley region (Hamilton and Hayes, 1960). morphic rocks form the coastal foothills and lower areas We are much indebted to L. H. Daugherty, S. H. in the central part of the range. Above these basement Mamay, J. J. Mulligan, and J. M. Schopf for permitting rocks in the central part of the range, and forming us to cite some of their unpublished data on the pale- nearly all the exposed rock of the western part of the obotany of the Beacon Sandstone. To Schopf in partic­ range, is the almost undef ormed Beacon Sandstone and ular must also go much of the credit for the discussion the diabase sheets intruded into it. of paleobotany and age of the Beacon. Our fieldwork on the type section was done during This work was carried out on behalf of the National November 1958, from a camp on Taylor Glacier, to Science Foundation. TYPE SECTION OF BEACON SANDSTONE OF ANTARCTICA A3 EXPLANATION Plutonic basement complex Fault Mountain peak 3 MILES 4 KILOMETERS FIGCEE 3. Geologic map -of Beacon Heights and vicinity. Map prepared by photogrammetric methods from vertical aerial photographs, sup­ plemented by field observations and by ground and oblique aerial photographs. Dashed contacts modified from McKelvey and Webb (1959). Arrows show direction of ice flow. A4 CONTRIBUTIONS TO THE GEOLOGY OF ANTARCTICA TYPE SECTION the northwest. McKelvey and Webb (1959) described The Beacon Sandstone of the type area (fig. 3) is the upper part of the sandstone 3 miles farther west. about 4,000 feet thick and dips 2°-4° westward. The All but the basal strata of the Beacon are divisible few faults are short and of small displacement. Injec­ into three easily recognized units in the type area and ted into the sandstone are huge sills and inclined sheets the surrounding region. The lower unit, here referred of quartz diabase with an aggregate thickness of about to as the sandstone of New Mountain, is ledge-forming 4,000 feet, so that the total thickness of sandstone and sandstone. The middle unit, the sandstone of Pyramid diabase is about 8,000 feet. The local relief is but 4,000 Mountain, is thick bedded and cliff forming. The upper feet, and it is necessary to define a composite type section unit, the sandstone of Finger Mountain, is ledge forming from separate traverses. and includes much siltstone and carbonaceous strata. The base of the Beacon Sandstone crops out at the These units are defined more fully on page 10. southeast end of the mountain mass of the type area, and here Zeller and others (1961) described the lower LOWER PART part of the formation. We measured the middle part The base and lower part of the Beacon Sandstone of the formation at West Beacon Heights, 7 miles to were examined by Zeller and others (1961) on the FIGURE 4. New Mountain, seen from the north, showing the lower part of the Beacon Sandstone. Pre-Devonian basement rocks crop out at base of bluffs by Windy Gully. A thick diabase sill lies near the base of the Beacon, and another is at the top of New Mountain.
Load more

Recommended publications
  • A Palaeoenvironmental Reconstruction of the Middle Jurassic of Sardinia (Italy) Based on Integrated Palaeobotanical, Palynological and Lithofacies Data Assessment
    Palaeobio Palaeoenv DOI 10.1007/s12549-017-0306-z ORIGINAL PAPER A palaeoenvironmental reconstruction of the Middle Jurassic of Sardinia (Italy) based on integrated palaeobotanical, palynological and lithofacies data assessment Luca Giacomo Costamagna1 & Evelyn Kustatscher2,3 & Giovanni Giuseppe Scanu1 & Myriam Del Rio1 & Paola Pittau1 & Johanna H. A. van Konijnenburg-van Cittert4,5 Received: 15 May 2017 /Accepted: 19 September 2017 # The Author(s) 2017. This article is an open access publication Abstract During the Jurassic, Sardinia was close to con- diverse landscape with a variety of habitats. Collection- tinental Europe. Emerged lands started from a single is- and literature-based palaeobotanical, palynological and land forming in time a progressively sinking archipelago. lithofacies studies were carried out on the Genna Selole This complex palaeogeographic situation gave origin to a Formation for palaeoenvironmental interpretations. They evidence a generally warm and humid climate, affected occasionally by drier periods. Several distinct ecosystems can be discerned in this climate, including alluvial fans This article is a contribution to the special issue BJurassic biodiversity and with braided streams (Laconi-Gadoni lithofacies), paralic ^ terrestrial environments . swamps and coasts (Nurri-Escalaplano lithofacies), and lagoons and shallow marine environments (Ussassai- * Evelyn Kustatscher [email protected] Perdasdefogu lithofacies). The non-marine environments were covered by extensive lowland and a reduced coastal Luca Giacomo Costamagna and tidally influenced environment. Both the river and the [email protected] upland/hinterland environments are of limited impact for Giovanni Giuseppe Scanu the reconstruction. The difference between the composi- [email protected] tion of the palynological and palaeobotanical associations evidence the discrepancies obtained using only one of those Myriam Del Rio [email protected] proxies.
    [Show full text]
  • Cretaceous Deposits and Flora of the Muravyov Amurskii Peninsula
    ISSN 08695938, Stratigraphy and Geological Correlation, 2015, Vol. 23, No. 3, pp. 281–299. © Pleiades Publishing, Ltd., 2015. Original Russian Text © E.B. Volynets, 2015, published in Stratigrafiya. Geologicheskaya Korrelyatsiya, 2015, Vol. 23, No. 3, pp. 50–68. Cretaceous Deposits and Flora of the MuravyovAmurskii Peninsula (Amur Bay, Sea of Japan) E. B. Volynets Institute of Biology and Soil Science, Far East Branch, Russian Academy of Sciences, pr. 100letiya Vladivostoka 159, Vladivostok, 690022 Russia email: [email protected] Received August 21, 2013; in final form, March 24, 2014 Abstract—The Cretaceous sections and plant macrofossils are investigated in detail near Vladivostok on the MuravyovAmurskii Peninsula of southern Primorye. It is established that the Ussuri and Lipovtsy forma tions in the reference section of the Markovskii Peninsula rest with unconformity upon Upper Triassic strata. The continuous Cretaceous succession is revealed in the Peschanka River area of the northern Muravyov Amurskii Peninsula, where plant remains were first sampled from the lower and upper parts of the Korkino Group, which are determined to be the late Albian–late Cenmanian in age. The taxonomic composition of floral assemblages from the Ussuri, Lipovtsy, and Galenki formations is widened owing to additional finds of plant remains. The Korkino Group received floral characteristics for the first time. The Cretaceous flora of the peninsula is represented by 126 taxa. It is established that ferns and conifers are dominant elements of the Ussuri floral assemblage, while the Lipovtsy Assemblage is dominated by ferns, conifers, and cycadphytes. In addition, the latter assemblage is characterized by the highest taxonomic diversity. The Galenki Assemblage is marked by the first appearance of rare flowering plants against the background of dominant ferns and coni fers.
    [Show full text]
  • The Lower Cretaceous Flora of the Gates Formation from Western Canada
    The Lower Cretaceous Flora of the Gates Formation from Western Canada A Shesis Submitted to the College of Graduate Studies and Research in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Department of Geological Sciences Univ. of Saska., Saskatoon?SI(, Canada S7N 3E2 b~ Zhihui Wan @ Copyright Zhihui Mian, 1996. Al1 rights reserved. National Library Bibliothèque nationale 1*1 of Canada du Canada Acquisitions and Acquisitions et Bibliographic Services services bibliographiques 395 Wellington Street 395. rue Wellington Ottawa ON KlA ON4 Ottawa ON K1A ON4 Canada Canada The author has granted a non- L'auteur a accordé une licence non exclusive licence allowing the exclusive permettant à la National Libraxy of Canada to Bibliothèque nationale du Canada de reproduce, loan, distribute or sell reproduire, prêter, distribuer ou copies of this thesis in microfom, vendre des copies de cette thèse sous paper or electronic formats. la fome de microfiche/nlm, de reproduction sur papier ou sur foxmat électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts fiom it Ni la thèse ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. College of Graduate Studies and Research SUMMARY OF DISSERTATION Submitted in partial fulfillment of the requirernents for the DEGREE OF DOCTOR OF PHILOSOPHY ZHIRUI WAN Depart ment of Geological Sciences University of Saskatchewan Examining Commit tee: Dr.
    [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]
  • A Stable Isotopic Investigation of Resource Partitioning Among Neosauropod Dinosaurs of the Upper Jurassic Morrison Formation
    A stable isotopic investigation of resource partitioning among neosauropod dinosaurs of the Upper Jurassic Morrison Formation Benjamin T. Breeden, III SID: 110305422 [email protected] GEOL394H University of Maryland, College Park, Department of Geology 29 April 2011 Advisors: Dr. Thomas R. Holtz1, Jr., Dr. Alan Jay Kaufman1, and Dr. Matthew T. Carrano2 1: University of Maryland, College Park, Department of Geology 2: National Museum of Natural History, Department of Paleobiology ABSTRACT For more than a century, morphological studies have been used to attempt to understand the partitioning of resources in the Morrison Fauna, particularly between members of the two major clades of neosauropod (long-necked, megaherbivorous) dinosaurs: Diplodocidae and Macronaria. While it is generally accepted that most macronarians fed 3-5m above the ground, the feeding habits of diplodocids are somewhat more enigmatic; it is not clear whether diplodocids fed higher or lower than macronarians. While many studies exploring sauropod resource portioning have focused on differences in the morphologies of the two groups, few have utilized geochemical evidence. Stable isotope geochemistry has become an increasingly common and reliable means of investigating paleoecological questions, and due to the resistance of tooth enamel to diagenetic alteration, fossil teeth can provide invaluable paleoecological and behavioral data that would be otherwise unobtainable. Studies in the Ituri Rainforest in the Democratic Republic of the Congo, have shown that stable isotope ratios measured in the teeth of herbivores reflect the heights at which these animals fed in the forest due to isotopic variation in plants with height caused by differences in humidity at the forest floor and the top of the forest exposed to the atmosphere.
    [Show full text]
  • Dr. Sahanaj Jamil Associate Professor of Botany M.L.S.M. College, Darbhanga
    Subject BOTANY Paper No V Paper Code BOT521 Topic Taxonomy and Diversity of Seed Plant: Gymnosperms & Angiosperms Dr. Sahanaj Jamil Associate Professor of Botany M.L.S.M. College, Darbhanga BOTANY PG SEMESTER – II, PAPER –V BOT521: Taxonomy and Diversity of seed plants UNIT- I BOTANY PG SEMESTER – II, PAPER –V BOT521: Taxonomy and Diversity of seed plants Classification of Gymnosperms. # Robert Brown (1827) for the first time recognized Gymnosperm as a group distinct from angiosperm due to the presence of naked ovules. BENTHAM and HOOKSER (1862-1883) consider them equivalent to dicotyledons and monocotyledons and placed between these two groups of angiosperm. They recognized three classes of gymnosperm, Cyacadaceae, coniferac and gnetaceae. Later ENGLER (1889) created a group Gnikgoales to accommodate the genus giankgo. Van Tieghem (1898) treated Gymnosperm as one of the two subdivision of spermatophyte. To accommodate the fossil members three more classes- Pteridospermae, Cordaitales, and Bennettitales where created. Coulter and chamberlain (1919), Engler and Prantl (1926), Rendle (1926) and other considered Gymnosperm as a division of spermatophyta, Phanerogamia or Embryoptyta and they further divided them into seven orders: - i) Cycadofilicales ii) Cycadales iii) Bennettitales iv) Ginkgoales v) Coniferales vi) Corditales vii) Gnetales On the basis of wood structure steward (1919) divided Gymnosperm into two classes: - i) Manoxylic ii) Pycnoxylic The various classification of Gymnosperm proposed by various workers are as follows: - i) Sahni (1920): - He recognized two sub-divison in gymnosperm: - a) Phylospermae b) Stachyospermae BOTANY PG SEMESTER – II, PAPER –V BOT521: Taxonomy and Diversity of seed plants ii) Classification proposed by chamber lain (1934): - He divided Gymnosperm into two divisions: - a) Cycadophyta b) Coniterophyta iii) Classification proposed by Tippo (1942):- He considered Gymnosperm as a class of the sub- phylum pteropsida and divided them into two sub classes:- a) Cycadophyta b) Coniferophyta iv) D.
    [Show full text]
  • Biodiversity and the Reconstruction of Early Jurassic Flora from the Mecsek
    Acta Palaeobotanica 51(2): 127–179, 2011 Biodiversity and the reconstruction of Early Jurassic fl ora from the Mecsek Mountains (southern Hungary) MARIA BARBACKA Hungarian Natural History Museum, Department of Botany, H-1476, P.O. Box 222, W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Kraków, Poland; e-mail: [email protected] Received 15 June 2011; accepted for publication 27 October 2011 ABSTRACT. Rich material from Hungary’s Early Jurassic (the Mecsek Mts.) was investigated in a palaeoen- vironmental context. The locality (or, more precisely, area with a number of fossiliferous sites) is known as a delta plain, showing diverse facies, which suggest different landscapes with corresponding plant assemblages. Taphonomical observations proved that autochthonous and parautochthonous plant associations were present. The reconstruction of the biomes is based on the co-occurrence of taxa and their connection with the rock matrix and sites in the locality, as well as the environmental adaptation of the plants expressed in their morphology and cuticular structure. The climatic parameters were confi rmed as typical for the Early Jurassic by resolution of a palaeoatmospheric CO2 level based on the stomatal index of one of the common species, Ginkgoites mar- ginatus (Nathorst) Florin. Plant communities were differentiated with the help of Detrended Correspondence Analysis (DCA); the rela- tionship between taxa and sites and lithofacies and sites, were analysed by Ward’s minimal variance and cluste- red with the help
    [Show full text]
  • Terra Antartica Reports No. 16
    © Terra Antartica Publication Terra Antartica Reports No. 16 Geothematic Mapping of the Italian Programma Nazionale di Ricerche in Antartide in the Terra Nova Bay Area Introductory Notes to the Map Case Editors C. Baroni, M. Frezzotti, A. Meloni, G. Orombelli, P.C. Pertusati & C.A. Ricci This case contains four geothematic maps of the Terra Nova Bay area where the Italian Programma Nazionale di Ricerche in Antartide (PNRA) begun its activies in 1985 and the Italian coastal station Mario Zucchelli was constructed. The production of thematic maps was possible only thanks to the big financial and logistical effort of PNRA, and involved many persons (technicians, field guides, pilots, researchers). Special thanks go to the authors of the photos: Carlo Baroni, Gianni Capponi, Robert McPhail (NZ pilot), Giuseppe Orombelli, Piero Carlo Pertusati, and PNRA. This map case is dedicated to the memory of two recently deceased Italian geologists who significantly contributed to the geological mapping in Antarctica: Bruno Lombardo and Marco Meccheri. Recurrent acronyms ASPA Antarctic Specially Protected Area GIGAMAP German-Italian Geological Antarctic Map Programme HSM Historical Site or Monument NVL Northern Victoria Land PNRA Programma Nazionale di Ricerche in Antartide USGS United States Geological Survey Terra anTarTica reporTs, no. 16 ISBN 978-88-88395-13-5 All rights reserved © 2017, Terra Antartica Publication, Siena Terra Antartica Reports 2017, 16 Geothematic Mapping of the Italian Programma Nazionale di Ricerche in Antartide in the Terra Nova
    [Show full text]
  • Cotnparison Between Glacier Ice Velocities Inferred Frotn GPS and Sequential Satellite Itnages
    Annals ifGlaciology 27 1998 © International Glaciological Society Cotnparison between glacier ice velocities inferred frotn GPS and sequential satellite itnages MASSIMO FREZZOTTI/ ALEsSANDRO CAPRA,2 LUCA VITTUARI2 I ENEA Dip. Ambiente, CRE Casaccia, PO. Box 2400, 1-00100 Rome AD, Italy 2 DISTART, University ifBologna, Viale Risorgimento 2, 1-40136 Bologna, Italy ABSTRACT. Measurements derived from remote-sensing research and field surveys have provided new ice-velocity data for David Glacier--Drygalski Ice Tongue and Priest­ ley and Reeves Glaciers, Antarctica. Average surface velocities were determined by track­ ing crevasses and other patterns moving with the ice in two sequential satellite images. Velocity measurements were made for different time intervals (1973- 90, 1990- 92, etc.) using images from various satellite sensors (Landsat 1 MSS, LandsatTM, SPOT XS). In a study of the dynamics ofDavid Glacier- Drygalski Ice Tongue and Priestley and Reeves G laciers, global positioning system (GPS) measurements were made between 1989 and 1994. A number of points were measured on each glacier: five points on David Glacier, three on Drygalski Ice Tongue, two on Reeves Glacier- Nansen Ice Sheet and two on Priestley Glacier. Comparison of the results from GPS data and feature-tracking in areas close to image tie-points shows that errors in measured average velocity from the feature­ tracking may be as little as ± 15-20 m a I. In areas far from tie-points, such as the outer part of Drygalski Ice Tonpue, comparison of the two types of measurements shows differ­ ences of about ± 70 m a - . INTRODUCTION ments from field surveys (Bindschadler and others, 1994, 1996).
    [Show full text]
  • Taylorsville Region, California
    DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIRECTOR 353 GEOLOGY OF THE TAYLORSVILLE REGION, CALIFORNIA BY J. S. DILLER WASHINGTON GOVERNMENT PRINTING OFFICE 1908 t f CONTENTS. Page Introduction.............................................................. 7 Location and extent................................................... 7 Outline of geography and geology of region.............................. 7 Topography............................................................... 9 Relief. ............................................................... 9 Diamond Mountain block.......................................... 9 The escarpment. .............................................. 10 The plateau slope.............................................. 10 Valleys on southwest border.................................... 10 Genesee Valley............................................. 10 Indian Valley............................................. 10 Mountain Meadows........................................ 11 Jura Valley................................................ 11 Grizzly Mountain block........................................... 11 Crest line and escarpment..................................... 11 Southwest slope............................................... .12 Drainage.............................................................. 12 Descriptive geology........................................................ 13 General statement........'............................................... 13 Sedimentary rocks....................................................
    [Show full text]
  • Reconstructing Paleoclimate and Landscape History in Antarctica and Tibet with Cosmogenic Nuclides
    Research Collection Doctoral Thesis Reconstructing paleoclimate and landscape history in Antarctica and Tibet with cosmogenic nuclides Author(s): Oberholzer, Peter Publication Date: 2004 Permanent Link: https://doi.org/10.3929/ethz-a-004830139 Rights / License: In Copyright - Non-Commercial Use Permitted This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library DISS ETH NO. 15472 RECONSTRUCTING PALEOCLIMATE AND LANDSCAPE HISTORY IN ANTARCTICA AND TIBET WITH COSMOGENIC NUCLIDES A dissertation submitted to the SWISS FEDERAL INSTITUTE OF TECHNOLOGY ZURICH For the degree of Doctor of Sciences presented by PETER OBERHOLZER dipl. Natw. ETH born 14. 08.1969 citizen of Goldingen SG and Meilen ZH accepted on the recommendation of Prof. Dr. Rainer Wieler, examiner Prof. Dr. Christian Schliichter, co-examiner Prof. Dr. Carlo Baroni, co-examiner Dr. Jörg M. Schäfer, co-examiner Prof. Dr. Philip Allen, co-examiner 11 Contents 1 Introduction 1 1.1 Climate and landscape evolution 2 1.2 Archives of the paleoclimate 2 1.3 Antarctica and Tibet - key areas of global climate 3 1.4 Surface exposure dating 3 2 Method 7 2.1 A brief history 8 2.2 Principles of surface exposure dating 8 2.3 Sampling 14 2.4 Sample preparation 17 2.5 Noble gas extraction and measurements 18 2.6 Non-cosmogenic noble gas fractions 20 3 Antarctica 27 3.1 Introduction 28 3.2 Relict ice in Beacon Valley 32 3.3 Vernier Valley moraines 42 3.4 Mount Keinath 51 3.5 Erosional surfaces in Northern Victoria Land 71 4 Tibet 91 4.1 Introduction 92 4.2 Tibet: The MIS 2 advance 98 4.3 Tibet: The MIS 3 denudation event 108 5 Europe 127 5.1 Lower Saxony 128 5.2 The landslide of Kofels 134 6 Conclusions 137 6.1 Conclusions 138 6.2 Outlook 139 iii Contents A Appendix 155 A.l Additional samples 156 A.2 Sample weights 158 A.3 Sample codes of Mt.
    [Show full text]
  • Caytoniales Name of Teacher – Smt
    Subject – Gymnosperms Topic – Caytoniales Name of teacher – Smt . Sibi O.S. Academic year – 2020 – 2021 ➢ Caytoniales were a small group of extinct gymnospermic plants. ➢ First described by Hamshaw Thomas in 1925 from late Triassic period. ➢ Caytonia is a berry like cupules with numerous small seeds. Examples of Caytoniales ➢ Leaves : Sagenopteris ➢ Microsporophyll : Caytonanthus ➢ Megasporophylls: Caytonia and Gristhorpia General characteristics ➢ Caytoniales were small branched trees or shrubs. ➢ Leaves ( Sagenopteris ). ➢ Leaves petiolate. ➢ Petiole slender with 3 to 6 terminal leaflets. ➢ Leaflets arrangement was palmate in pairs. Sagenopteris ➢ Each leaflet with distinct midrib. ➢ Leaf margin smooth with an acute apex. ➢ Venation similar to glossopteris. ➢ Upper and lower epidermis with thick cuticle. ➢ Stomatal development haplocheilic. ➢ Mesophyll differentiated into palisade and transfusion tissue. ➢ Leaflets fall by the formation of abscission layers , it is an Angiospermic character . ➢ Caytoniales had fertile branches with seed bearing cupules. ➢ Ovules were located inside the fleshy cupules with tough outer cuticle . ➢ Outer layers of the cupules were fleshy and fruit – like. ➢ Individual ovules had an apical tube like structure called micropylar canal. ➢ Mature ovule resembles a blueberry fruit. ➢ The extra protection of seeds in Caytoniales indicates they were predecessors of angiosperms Microsporophyll ➢ Example : Caytonanthus ➢ Microsporophyll consists of dorsi – ventral and pinnate rachis. ➢ Each rachis bears pinnate on either side. ➢ Each pinnae branches irregularly. ➢ The ultimate branches of pinnae bear the synangia. ➢ Each branch bears two sporangia terminally. ➢ Each sporangium was with four pollen sacs . ➢ Pollen grains were produced in the pollen sacs in groups of four. ➢ Pollen grains were small , shape similar to that of pine trees ➢ Pollen grains winged. ➢ Pollination is achieved through the wind.
    [Show full text]