DOCSLIB.ORG

Geodynamic Links Between the Transantarctic Mountains and Tethys RASOUL B

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geodynamic Links Between the Transantarctic Mountains and Tethys RASOUL B ated surfaces suggest deposition from wet-based terrestrial gist Range and the All Black Nunataks and at Mount Cerberus glaciers. and Turbidite Hill. Sandstones contain abundant silicified Black shales of the overlying Mackellar Formation are in logs, some of which are contained within large deformed sharp contact with diamictite and sandstone of the Pagoda mudstone clasts. The presence of mudstone clast suggest Formation. Lonestones are extremely rare in these shales and slumping of cutbanks into the adjacent channel. The associ- were observed only in the lower 1.5 m. Two coarsening-upward ated logs were probably transported only a few hundred sequences occur within rocks of the Mackellar Formation. meters or less. Silicified peat and logs in the Nimrod-Byrd These sequences consist of basal shales that grade upward into area occur lower in the Buckley Formation than similar fossils interstratified cross-laminated sandstone (0.01-0.1 m thick) in the Beardmore Glacier region. These fossils may be the old- and shale (0.1-0.5 m thick); the shale in turn grades into hori- est silicified Permian plant material in the central zontally and cross laminated sandstone (1-10 m thick). Sand- Transantarctic Mountains. stone at the top of the lower sequences is in sharp contact with We are grateful to Nicholas Rowe, Shaun Norman, and black shale of the overlying sequence. The second sequence Mike Roberts for their help in the field. Dr. Rowe collected coarsens upward into medium-grained sandstone of the most of the plant fossils reported in this paper. These fossils Fairchild Formation. Shales in the Mackellar were deposited are being examined at the paleobotanical laboratory at the from suspension in a basinal setting. Sandstones were intro- Ohio State University. Logistics in Antarctica were provided duced into this environment as underfiow currents in front of a by Antarctic Support Associates, the U.S. Navy Squadron VXE- prograding deltaic system. The sharp lower contact of the 6, Ken Bork Air Ltd., and the National Science Foundation. Mackellar Formation is a flooding surface and suggests rapid This research was supported by National Science Foundation destruction of the late Paleozoic ice sheets followed by flooding grant OPP 91-18495. of the depositional basin. The sharp contact separating the two coarsening-upward sequences is also a flooding surface and due to its widespread distribution across the Byrd-Nimrod area References indicates a rapid rise in basinal water levels. Barrett, P.J., and B.P. Kohn. 1975. Changing sediment transport direc- Basal medium-grained sandstones of the 150-rn-thick tions from Devonian to Triassic in the Beacon Supergroup of Fairchild Formation contain dipping foreset beds 1-5 rn thick south Victoria Land, Antarctica. In K.S.W. Campbell (Ed.), Gond- These foresets dip at 4-16 0 and grade downward into fine- wana geology. Canberra: Australian National University Press. grained sandstone that interfingers with shale in the underlying Bradshaw, M.A., F.J. Harmsen, and M.P. Kirkbride. 1990. Preliminary Mackellar Formation. Upward, the Fairchild is characterized by results of the 1988-1989 expedition to the Darwin Glacier area. New Zealand Antarctic Record, 10(1), 28-48. sandstone filled channel-form structures. Deltaic sedimenta- Collinson, J.W., J.L. Isbell, D.H. Elliot, M.F. Miller, and J.M.G. Miller. tion characterizes the lower Fairchild, whereas rocks in the In press. Transantarctic Basin. In J.J. Veevers (Ed.), Paleo -Pacific upper portions of the unit were deposited by braided streams. margin of Gondwana (Geological Society of America Memoir). The 250(+) -m-thick Buckley Formation consists predomi- New York: Geological Society of America. nantly of coarse-grained sandstone (5-40 m thick) interstrati- Elliot, D.H. 1975. Gondwana basins in Antarctica. In K.S.W. Campbell (Ed.), Gondwana geology. Canberra: Australian National Univer- fled with shale (0.5-5 rn thick) and coal (0.05-0.3 m thick) sity Press. beds. The sandstones occur as sheets, which contain numer- Grindley, G.W., and M.G. Laird. 1969. Sheet 15, Shackleton Coast geo- ous downstream accreting macroforms surfaces and sand- logic map of Antarctica, 1:1,000,000. In Antarctic Map Folio Series, stone-filled channel structures. The Buckley was deposited Plate XfV Folio 12—Geology. New York: American Geographical within a braided stream depositional system. Society. Compression, impression, silicified peat, and silicified Laird, M.G., G.D. Mansergh, and J.M.A. Chappell. 1971. Geology of the central Nimrod Glacier area, Antarctica. New Zealand Journal of logs were collected from the Buckley Formation in the Geolo- Geology and Geophysics, 14(3), 427-468. Geodynamic links between the Transantarctic Mountains and Tethys RASOUL B. SoRIulArn and EDMUND STUMP, Department of Geology, Arizona State University, Tempe, Arizona 85287-1404 he Transantarctic Mountains, extending for approximately antarctic crust, with the mountains forming the shoulder of a T3,500 kilometers, constitute a major morphotectonic rift system on the east antarctic side (e.g., Fitzgerald et al. 1986; boundary between the Precambrian craton of East Antarctica Stern and ten Brink 1989). Therefore, the Transantarctic and the continental "collage" of West Antarctica (figure 1; Mountains do not represent an "orogen" resulting from con- Elliot 1985, pp. 39-61). The genesis of the Transantarctic vergence of tectonic plates but, rather, a "taphrogen" related Mountains has been attributed to an extensional regime in the to fault-block uplifts of a thinning crust. ANTARCTIC JOURNAL - REVIEW 1994 36 (Africa-South America) and East Gondwanaland (Antarctica- (Sbrkneykmnds India-Australia) resulting in the widening of the Weddell Sea. S Shetland Islands (We have followed the review by Lawyer et al. 1991, pp. Sea Weddell 2 IV Maud L OARarcfica 533-539, and references therein for the timing of breakup of Peninsula - - / Gondwanaland). Africa separated from Antarctica around 150 Larson / Enderby /#ct,ner -?- eos million years ago. Initiation of a rapid phase of uplift- \ Ice Shelf -, hackIeton exhumation in the Ellsworth Mountains of West Antarctica Ale shortly before 140 million years ago, as shown by fission-track data, probably records tectonism of the region related to this Sea 901W 1>0 Po .^ S breakup (Fitzgerald and Stump 1991). This was followed by rift-volcanism between Africa and Th.won WEST % ANTARCTICA South America approximately 130 million years ago, a rift that Amurlen Made ultimately led to the opening of the South Atlantic Ocean. Geometrically, the Transantarctic Mountains lie online with Ice shelf edge S- Ross Sea the South Atlantic Mid-Ocean Ridge. Sufficient separation Ice surface elevation in km Vlsi between West and East Gondwanaland possibly prevented 2000m bathyrnetric contour Basin Extent of s bglac at features this sea-floor spreading from extending to the locus of the Generalized area of rock exposure 70 + _. Transantarctic Mountains. Nevertheless, the Transantarctic Transantarcf IC Mountains 0- km Mountains seem to have been affected by the same line of Ellsworth Mountains - - 1000 mites tension. The continuous uplift-exhumation as documented Figure 1. A physiographic map of Antarctica (modified after Elliot by fission-track data in the Ellsworth Mountains may be a 1985, 39-61). (m denotes meter.) pp. record of this extensional event, and we suspect that the Early The Transantarctic Mountains taphrogeny is geodynami- Cretaceous phase of rift-block uplifts was widely spread in the cally related to major plate reorganizations surrounding Transantarctic Mountains. Antarctica. With this view, we suggest here a scenario for the The fragmentation of Gondwanaland seems to have fol- formation of the Transantarctic Mountains in light of the lowed a clockwise (west-east) direction (Behrendt, LeMa- breakup of Gondwanaland and the opening and closure of surier, and Cooper 1992, pp. 315-322) so that after Africa, the the Mesozoic Tethyan Ocean(s) lying between Gondwanaland next continent to break away was India approximately 120 and the northern supercontinent of Laurasia (figure 2). million years ago. Australia separated from Antarctica proba- SengOr et al. (1988, pp. 119-181) have argued that the first bly around 95 million years ago. Separation of these conti- fragments to break away from Gondwanaland were those of nental blocks from the northerly margin of the east antarctic the Cimmerian continent (notably Tibetan, Iranian, and Turk- craton marked phases of uplift-exhumation in the ish plateaus) during Permian times. Evidence for this rifting is Transantarctic Mountains margin of East Antarctica as preserved in, for example, the Panjal Traps of the Himalaya (northern margin of the Indian plate) (Gansser 1964). The drift- ing Cimmerian continental blocks closed Paleo-Tethys, which then lay between Gond- wanaland and Laurasia and sub- sequently collided with the Eurasian plate during Late Juras- sic times. It is of note that the clo- sure of Paleo-Tethys was coeval with widespread alkaline/tholei- itic magmatism in Gondwana- land (e.g., the Ferrar dolerites of approximately 180 million years ago in the Transantarctic Moun- tains; Kyle, Elliot, and Sutter Laurasia Gondwana-land ftflflj Cimmerian Continent Exotic Blocks 1981, pp. 283-287). The magma- E tism in Gondwanaland ushered Palaeo-Tethayan sutures Atlantic sutures - Non-Tethayan sutures - Neo-Tethyan sutures in other episodes of fragmenta- (Circum-Pacific) (Alpine-Himalayan) tion in Gondwanaland (figure 3). Figure 2. A
Load more

Recommended publications
  • Office of Polar Programs
    DEVELOPMENT AND IMPLEMENTATION OF SURFACE TRAVERSE CAPABILITIES IN ANTARCTICA COMPREHENSIVE ENVIRONMENTAL EVALUATION DRAFT (15 January 2004) FINAL (30 August 2004) National Science Foundation 4201 Wilson Boulevard Arlington, Virginia 22230 DEVELOPMENT AND IMPLEMENTATION OF SURFACE TRAVERSE CAPABILITIES IN ANTARCTICA FINAL COMPREHENSIVE ENVIRONMENTAL EVALUATION TABLE OF CONTENTS 1.0 INTRODUCTION....................................................................................................................1-1 1.1 Purpose.......................................................................................................................................1-1 1.2 Comprehensive Environmental Evaluation (CEE) Process .......................................................1-1 1.3 Document Organization .............................................................................................................1-2 2.0 BACKGROUND OF SURFACE TRAVERSES IN ANTARCTICA..................................2-1 2.1 Introduction ................................................................................................................................2-1 2.2 Re-supply Traverses...................................................................................................................2-1 2.3 Scientific Traverses and Surface-Based Surveys .......................................................................2-5 3.0 ALTERNATIVES ....................................................................................................................3-1
    [Show full text]
  • Reevaluation of the Timing and Extent of Late Paleozoic Glaciation in Gondwana: Role of the Transantarctic Mountains
    Reevaluation of the timing and extent of late Paleozoic glaciation in Gondwana: Role of the Transantarctic Mountains John L. Isbell Department of Geosciences, University of Wisconsin, Milwaukee, Wisconsin 53201, USA Paul A. Lenaker Rosemary A. Askin Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210, USA Molly F. Miller Department of Earth and Environmental Science, Vanderbilt University, Nashville, Tennessee 37235, USA Loren E. Babcock Department of Geological Sciences and Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210, USA ABSTRACT Evidence from Antarctica indicates that a 2000-km-long section of the Transantarctic MountainsÐincluding Victoria Land, the Darwin Glacier region, and the central Transantarctic MountainsÐwas not located near the center of an enormous Car- boniferous to Early Permian ice sheet, as depicted in many paleo- Figure 1. Carboniferous and geographic reconstructions. Weathering pro®les and soft-sediment Permian paleogeographic map deformation immediately below the preglacial (pre-Permian) un- of Gondwana (after Powell and Li, 1994), showing several hy- conformity suggest an absence of ice cover during the Carbonif- pothetical ice sheets. erous; otherwise, multiple glacial cycles would have destroyed these features. The occurrence of glaciotectonite, massive and strat- i®ed diamictite, thrust sheets, sandstones containing dewatering structures, and lonestone-bearing shales in southern Victoria Land and the Darwin Glacier region indicate that Permian sedimenta- tion occurred in ice-marginal, periglacial, and/or glaciomarine set- tings. No evidence was found that indicates the Transantarctic Mountains were near a glacial spreading center during the late Paleozoic. Although these ®ndings do not negate Carboniferous Powell, 1987; Ziegler et al., 1997; Scotese, 1997; Scotese et al., 1999; glaciation in Antarctica, they do indicate that Gondwanan glacia- Veevers, 2000, 2001).
    [Show full text]
  • The Neogene Biota of the Transantarctic Mountains
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Related Publications from ANDRILL Affiliates Antarctic Drilling Program 2007 The Neogene biota of the Transantarctic Mountains A. C. Ashworth North Dakota State University, [email protected] A. R. Lewis North Dakota State University, [email protected] D. R. Marchant Boston University, [email protected] R. A. Askin [email protected] D. J. Cantrill Royal Botanic Gardens, [email protected] See next page for additional authors Follow this and additional works at: https://digitalcommons.unl.edu/andrillaffiliates Part of the Environmental Indicators and Impact Assessment Commons Ashworth, A. C.; Lewis, A. R.; Marchant, D. R.; Askin, R. A.; Cantrill, D. J.; Francis, J. E.; Leng, M. J.; Newton, A. E.; Raine, J. I.; Williams, M.; and Wolfe, A. P., "The Neogene biota of the Transantarctic Mountains" (2007). Related Publications from ANDRILL Affiliates. 5. https://digitalcommons.unl.edu/andrillaffiliates/5 This Article is brought to you for free and open access by the Antarctic Drilling Program at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Related Publications from ANDRILL Affiliates by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Authors A. C. Ashworth, A. R. Lewis, D. R. Marchant, R. A. Askin, D. J. Cantrill, J. E. Francis, M. J. Leng, A. E. Newton, J. I. Raine, M. Williams, and A. P. Wolfe This article is available at DigitalCommons@University of Nebraska - Lincoln: https://digitalcommons.unl.edu/ andrillaffiliates/5 U.S. Geological Survey and The National Academies; USGS OF-2007-1047, Extended Abstract.071 The Neogene biota of the Transantarctic Mountains A.
    [Show full text]
  • Fault Kinematic Studies in the Transantarctic Mountains, Southern Victoria Land TERRY J
    studies. Together these data will be used to develop a model to plate tectonic modeling. In R.A. Hodgson, S.P. Gay, Jr., and J.Y. of the structural architecture and motion history associated Benjamins (Eds.), Proceedings of the First International Conference with the Transantarctic Mountains in southern Victoria Land. on the New Basement Tectonics (Publication number 5). Utah Geo- logical Association. We thank Jane Ferrigno for cooperation and advice on Lucchita, B.K., J. Bowell, K.L. Edwards, E.M. Eliason, and H.M. Fergu- image selection; John Snowden, David Cunningham, and son. 1987. Multispectral Landsat images of Antarctica (U.S. Geo- Tracy Douglass at the Ohio State University Center for Map- logical Survey bulletin 1696). Washington, D.C.: U.S. Government ping for help with computer processing; and Carolyn Merry, Printing Office. Gary Murdock, and Ralph von Frese for helpful discussions Wilson, T.J. 1992. Mesozoic and Cenozoic kinematic evolution of the Transantarctic Mountains. In Y. Yoshida, K. Kaminuma, and K. concerning image analysis. This research was supported by Shiraishi (Eds.), Recent progress in antarctic earth science. Tokyo: National Science Foundation grant OPP 90-18055 and by the Terra Scientific. Byrd Polar Research Center of Ohio State University. Wilson, T.J. 1993. Jurassic faulting and magmatism in the Transantarctic Mountains: Implication for Gondwana breakup. In R.H. Findlay, M.R. Banks, R. Unrug, and J. Veevers (Eds.), Gond- References wana 8—Assembly, evolution, and dispersal. Rotterdam: A.A. Balkema. Wilson, T.J., P. Braddock, R.J. Janosy, and R.J. Elliot. 1993. Fault kine- Isachsen, Y.W. 1974.
    [Show full text]
  • 2010-2011 Science Planning Summaries
    Find information about current Link to project web sites and USAP projects using the find information about the principal investigator, event research and people involved. number station, and other indexes. Science Program Indexes: 2010-2011 Find information about current USAP projects using the Project Web Sites principal investigator, event number station, and other Principal Investigator Index indexes. USAP Program Indexes Aeronomy and Astrophysics Dr. Vladimir Papitashvili, program manager Organisms and Ecosystems Find more information about USAP projects by viewing Dr. Roberta Marinelli, program manager individual project web sites. Earth Sciences Dr. Alexandra Isern, program manager Glaciology 2010-2011 Field Season Dr. Julie Palais, program manager Other Information: Ocean and Atmospheric Sciences Dr. Peter Milne, program manager Home Page Artists and Writers Peter West, program manager Station Schedules International Polar Year (IPY) Education and Outreach Air Operations Renee D. Crain, program manager Valentine Kass, program manager Staffed Field Camps Sandra Welch, program manager Event Numbering System Integrated System Science Dr. Lisa Clough, program manager Institution Index USAP Station and Ship Indexes Amundsen-Scott South Pole Station McMurdo Station Palmer Station RVIB Nathaniel B. Palmer ARSV Laurence M. Gould Special Projects ODEN Icebreaker Event Number Index Technical Event Index Deploying Team Members Index Project Web Sites: 2010-2011 Find information about current USAP projects using the Principal Investigator Event No. Project Title principal investigator, event number station, and other indexes. Ainley, David B-031-M Adelie Penguin response to climate change at the individual, colony and metapopulation levels Amsler, Charles B-022-P Collaborative Research: The Find more information about chemical ecology of shallow- USAP projects by viewing individual project web sites.
    [Show full text]
  • Geology of Antarctica
    GEOLOGY OF ANTARCTICA 1. Global context of Antarctica Compared with other continents, the geological evolution of Antarctica is relatively little known, since less than 2% of the land emerges from beneath the thick cover of glacier ice. Yet where rocks are exposed, their pristine nature and lack of vegetation has enabled geologists to unravel many key components of the region’s history. In addition, the use of geophysical and remote sensing techniques, together with drilling on the Continental Shelf, has helped resolve many of the geological questions posed by the limited outcrop. Antarctica is the remotest of the world’s continents, with its nearest neighbour being South America, some 100 km (560 miles) distant. Yet, relatively early on in the geological exploration of Antarctica it was recognized that Antarctica shared a common history with other southern hemisphere continents, such as South America, Africa, Arabia, India and Australasia. However, these early ideas of movement of continents by joining together, followed by splitting apart, were ridiculed by many geologists and geophysicists, until the revolution in geological thinking in the late 1960s that led to the ‘theory of plate tectonics’. This collection of photographs is assembled to capture the spirit of Antarctica’s geological evolution, grouped according to the key events that have shaped the continent. A limited knowledge of geological processes and terms is required to fully appreciate this set. Conditions of use of images 1 Contributors (who retain copyright), to whom requests for reproduction should be sent, are listed after the caption by their initials. In general, reproduction of these relatively low-resolution images is permitted for educational purposes without prior permission, e.g.
    [Show full text]
  • 2020-2021 Science Planning Summaries
    Project Indexes Find information about projects approved for the 2020-2021 USAP field season using the available indexes. Project Web Sites Find more information about 2020-2021 USAP projects by viewing project web sites. More Information Additional information pertaining to the 2020-2021 Field Season. Home Page Station Schedules Air Operations Staffed Field Camps Event Numbering System 2020-2021 USAP Field Season Project Indexes Project Indexes Find information about projects approved for the 2020-2021 USAP field season using the USAP Program Indexes available indexes. Astrophysics and Geospace Sciences Dr. Robert Moore, Program Director Project Web Sites Organisms and Ecosystems Dr. Karla Heidelberg, Program Director Find more information about 2020-2021 USAP projects by Earth Sciences viewing project web sites. Dr. Michael Jackson, Program Director Glaciology Dr. Paul Cutler, Program Director More Information Ocean and Atmospheric Sciences Additional information pertaining Dr. Peter Milne, Program Director to the 2020-2021 Field Season. Integrated System Science Home Page TBD Station Schedules Antarctic Instrumentation & Research Facilities Air Operations Dr. Michael Jackson, Program Director Staffed Field Camps Education and Outreach Event Numbering System Ms. Elizabeth Rom; Program Director USAP Station and Vessel Indexes Amundsen-Scott South Pole Station McMurdo Station Palmer Station RVIB Nathaniel B. Palmer ARSV Laurence M. Gould Special Projects Principal Investigator Index Deploying Team Members Index Institution Index Event Number Index Technical Event Index Other Science Events Project Web Sites 2020-2021 USAP Field Season Project Indexes Project Indexes Find information about projects approved for the 2020-2021 USAP field season using the Project Web Sites available indexes. Principal Investigator/Link Event No.
    [Show full text]
  • The Last Forests on Antarctica: Reconstructing flora and Temperature from the Neogene Sirius Group, Transantarctic Mountains ⇑ Rhian L
    Organic Geochemistry 118 (2018) 4–14 Contents lists available at ScienceDirect Organic Geochemistry journal homepage: www.elsevier.com/locate/orggeochem The last forests on Antarctica: Reconstructing flora and temperature from the Neogene Sirius Group, Transantarctic Mountains ⇑ Rhian L. Rees-Owen a,b, , Fiona L. Gill a, Robert J. Newton a, Ruza F. Ivanovic´ a, Jane E. Francis c, James B. Riding d, Christopher H. Vane d, Raquel A. Lopes dos Santos d a School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK b School of Earth and Environmental Sciences, University of St Andrews, St Andrews KY16 9AL, UK c British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK d British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK article info abstract Article history: Fossil-bearing deposits in the Transantarctic Mountains, Antarctica indicate that, despite the cold nature Received 4 April 2017 of the continent’s climate, a tundra ecosystem grew during periods of ice sheet retreat in the mid to late Received in revised form 2 November 2017 Neogene (17–2.5 Ma), 480 km from the South Pole. To date, palaeotemperature reconstruction has been Accepted 5 January 2018 based only on biological ranges, thereby calling for a geochemical approach to understanding continental Available online 12 January 2018 climate and environment. There is contradictory evidence in the fossil record as to whether this flora was mixed angiosperm-conifer vegetation, or whether by this point conifers had disappeared from the conti- Keywords: nent. In order to address these questions, we have analysed, for the first time in sediments of this age, Antarctica plant and bacterial biomarkers in terrestrial sediments from the Transantarctic Mountains to reconstruct Neogene Sirius Group past temperature and vegetation during a period of East Antarctic Ice Sheet retreat.
    [Show full text]
  • Heterogeneous Upper Mantle Structure Beneath the Ross Sea Embayment and Marie Byrd Land, West Antarctica, Revealed by P-Wave Tomography ∗ Austin L
    Earth and Planetary Science Letters 513 (2019) 40–50 Contents lists available at ScienceDirect Earth and Planetary Science Letters www.elsevier.com/locate/epsl Heterogeneous upper mantle structure beneath the Ross Sea Embayment and Marie Byrd Land, West Antarctica, revealed by P-wave tomography ∗ Austin L. White-Gaynor a, , Andrew A. Nyblade a, Richard C. Aster b, Douglas A. Wiens c, Peter D. Bromirski d, Peter Gerstoft d, Ralph A. Stephen e, Samantha E. Hansen f, Terry Wilson g, Ian W. Dalziel h, Audrey D. Huerta i, J. Paul Winberry i, Sridhar Anandakrishnan a a Department of Geosciences, Pennsylvania State University, United States of America b Department of Geosciences, Warner College of Natural Resources, Colorado State University, United States of America c Department of Earth and Planetary Sciences, Washington University in St. Louis, United States of America d Scripps Institution of Oceanography, University of California, United States of America e Woods Hole Oceanographic Institution, United States of America f Department of Geological Sciences, University of Alabama, United States of America g School of Earth Sciences, Ohio State University, United States of America h Jackson School of Geosciences, University of Texas at Austin, United States of America i Department of Geological Sciences, Central Washington University, United States of America a r t i c l e i n f o a b s t r a c t Article history: We present an upper mantle P-wave velocity model for the Ross Sea Embayment (RSE) region of West Received 29 July 2018 Antarctica, constructed by inverting relative P-wave travel-times from 1881 teleseismic earthquakes Received in revised form 16 January 2019 recorded by two temporary broadband seismograph deployments on the Ross Ice Shelf, as well as by Accepted 10 February 2019 regional ice- and rock-sited seismic stations surrounding the RSE.
    [Show full text]
  • The Transantarctic Mountains These Watercolor Paintings by Dee Molenaar Were Originally Published in 1985 with His Map of the Mcmurdo Sound Area of Antarctica
    The Transantarctic Mountains These watercolor paintings by Dee Molenaar were originally published in 1985 with his map of the McMurdo Sound area of Antarctica. We are pleased to republish these paintings with the permission of the artist who owns the copyright. Gunter Faure · Teresa M. Mensing The Transantarctic Mountains Rocks, Ice, Meteorites and Water Gunter Faure Teresa M. Mensing The Ohio State University The Ohio State University School of Earth Sciences School of Earth Sciences and Byrd Polar Research Center and Byrd Polar Research Center 275 Mendenhall Laboratory 1465 Mt. Vernon Ave. 125 South Oval Mall Marion, Ohio 43302 Columbus, Ohio 43210 USA USA [email protected] [email protected] ISBN 978-1-4020-8406-5 e-ISBN 978-90-481-9390-5 DOI 10.1007/978-90-481-9390-5 Springer Dordrecht Heidelberg London New York Library of Congress Control Number: 2010931610 © Springer Science+Business Media B.V. 2010 No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Cover illustration: A tent camp in the Mesa Range of northern Victoria Land at the foot of Mt. Masley. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) We dedicate this book to Lois M. Jones, Eileen McSaveny, Terry Tickhill, and Kay Lindsay who were the first team of women to conduct fieldwork in the Transantarctic Mountains during the 1969/1970 field season.
    [Show full text]
  • Ross Island Trail System Mcmurdo Station & Scott Base, Antarctica
    Ross Island Trail System McMurdo Station & Scott Base, Antarctica Ross Island Trail System Recreational Routes CAL Seasonal Trail Please visit the McMurdo Intranet eFoot Plan site for further route information (route marked with trail signs) markers in mi (km): e.g. 1.22 (1.96) CRL Castle Rock Loop Trail & CRS Castle Rock Summit Trail (9.65 mi / 15.53 km) (0.1 mi / 0.17 km) IR Access Road (shared with vehicles) CRS This trip leads to the prominent landform called Castle Rock, named for its buttress-like shape. The Castle Rock routes are the most ambitious hikes, ski or runs in the McMurdo area. As you traverse across the snow and ice field, you see the prominent 0.11 (0.17) landform of Castle Rock ahead, spectacular views to the north, and the Transantarctic Mountains to the east. The route is also Castle Rock a large loop that extends to Castle Rock and ends at Scott Base. More adventurous hikers may want to attempt the Castle Rock Restricted Road Summit route. This route entails scrambling, exposed rock faces and the use of a fixed line as a handhold and should never be (no recreational travel) attempted without an experienced person in your group. The Castle Rock Summit is only open at certain periods due to safety CASTLE ROCK FALL CRL concerns. January 30, 1995 Check-in/Check-out 1 death (Building 182 Firehouse) HPR Hut Point Ridge Loop Trail 1.33 (2.13) (2.63 mi / 4.24 km) The Hut Point Ridge Loop Trail is one of the newest additions to recreation opportunities in the Ross Island area.
    [Show full text]
  • An Active Neoproterozoic Margin: Evidence from the Skelton Glacier Area, Transantarctic Mountains
    Journal of the Geological Society, London, Vol. 1511, 1993, pp. 677-682, figs. 4 Printed in Northern Ireland An active Neoproterozoic margin: evidence from the Skelton Glacier area, Transantarctic Mountains A. J. ROWELL l, M. N. REES 2, E. M. DUEBENDORFER 2, E. T. WALLIN 2, W. R. VAN SCHMUS l, & E. I. SMITH 2 1Department of Geology, University of Kansas, Lawrence, KS 66045, USA 2Department of Geoscience, University of Nevada, Las Vegas, NV 89154, USA Abstract: Metamorphosed supracrustal rocks in the central Ross Sea sector of the Transantarctic Mountains are of Neoproterozoic age and not Cambrian. They include pillow basalts with a mantle separation age of 700-800 Ma. In the Skelton Glacier area, these rocks experienced two strong phases of deformation that produced folds and associated foliations. Both rocks and structures are cut by a 551 4-4 Ma unfoliated quartz syenite (late Neoproterozic). The deformation and limited geochemical data suggest an active Antarctic plate margin whose late Neoproterozoic history is markedly different from that of the temporally equivalent rift to drift transition recorded along the autochthonous western margin of Laurentia. If these two cratons were ever contiguous, separation occurred by c. 700-800 Ma. The Transantarctic Mountains are the product of late and renamed numerous times subsequently (Findlay 1990; Palaeogene-Neogene uplift (Webb 1991) along a line Smillie 1992). Metasedimentary strata in the Skelton Glacier subparallel to the boundary between the East Antarctic area are typically at greenschist facies and consist of the craton and the Ross orogen. Cambro-Ordovician granitoids Anthill Limestone overlain by the Cocks Formation (c.
    [Show full text]