DOCSLIB.ORG

Aspects of the Late Proterozoic and Paleozoic Geology of the Churchill

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Aspects of the Late Proterozoic and Paleozoic Geology of the Churchill This research was supported in part by National Science palynomorphs from the Buckley Formation on Mount Achernar, Foundation grant DPP 86-11884. The specimens were collected Antarctica. Grana.. by James W. Collinson, John L. Isbell, and the late James M. Kemp, E. 1974. Permian flora from the Beaver Lake area. 1. Palynol- ogical examination of samples. Bureau of Mineral Resources, Geology Schopf of the Byrd Polar Research Center. and Geophysics, Australia Bulletin, 126, 7-12. Kyle, R.A. 1976. Palaeobotanical studies of the Permian and Triassic Victoria Group (Beacon Supergroup) Gf South Victoria Land, Ant- arctica. (Unpublished doctoral dissertation, University of Welling- References ton, New Zealand.) Kyle, R.A. 1977. Palynostratigraphy of the Victoria Group of South Balme, BE., and C. Playford. 1967. Late Permian plant microsossils Victoria Land, Antarctica. New Zealand Journal of Geology and Geo- from the Prince Charles Mountains, Antarctica, Revue de Micropa- physics, 20, 1081-1102. leontologie, 10, 179-192. Kyle, R.A., and J.M. Schopf. 1977. Palynomorph preservation in the Barrett, P.J., D.H. Elliot, and P.J. Lindsay. 1986. The Beacon Super- Beacon Supergroup of the Transantarctic Mountains. Antarctic Jour- group (Devonian-Triassic) and Ferrar Group (Jurassic) in the Beard- nal of the U.S., 12(5), 121-122. more Glacier area, Antarctica. In M.D. Turner and J.F. Splettstoesser Kyle, R.A., and J.M. Schopf. 1982. Permian and Triassic palynostra- (Eds.), Geology of the central Transantarctic Mountains. (Antarctic Re- tigraphy of the Victoria Group, Transantarctic Mountains. In Pro- search Series, Vol. 36.) Washington, D.C.: American Geophysical ceedings of the 3rd Symposium on Antarctic Geology and Geophysics, Madison, Union. Wisconsin, 1977. Dibner, A.F. 1978. Palynocomplexes and age of the Amery Formation Tasch, P. 1978. Permian palynomorphs (Coalsack Bluff, Mount Sirius, deposits, East Antarctica. Pollen et Spores, 20, 504-422. Mount Picciotto) and other studies. Antarctic Journal of the U.S., 13(5), Farabee, M.J., E.L. Taylor, and T.N. Taylor. In press. Upper Permian 19-20. also mapped post-Permian normal faults that confirm sub- Aspects of the late Proterozoic stantial extensional deformation in the central Transantarctic and Paleozoic geology Mountains, and we collected carbonaceous and silicified plant fossils from a new locality (N-87-2; figure, block D) in sand- of the Churchill Mountains, stones of the Beacon Supergroup. southern Victoria Land Our field team consisted of Margaret N. Rees, Albert J. Row- ell, and two field assistants, Sarah Jones and Peter Braddock. We were put into our first field area (figure, block C) by an MARGARET N. REES LC-130 ski-equipped Hercules airplane on the Nicholson Pen- insula (80°42S 159°22E) on 23 November 1987 and picked up Department of Geoscience there on 16 December. The put-in at our second field area University of Nevada at Las Vegas (figure, bock D), the Starshot Glacier (81°54S 158°29E), was Las Vegas, Nevada 89154 on 18 December, and we were pulled out on 6 January. Al- though much was accomplished at localities M, N, and 0 ALBERT J. ROWELL (figure, block D), numerous days of poor visibility resulted in only 1 day at locality P to examine the Starshot Formation, and Department of Geology consequently, the relationships there are still unresolved. University of Kansas Four formations have been referred to the Byrd Group: Lawrence, Kansas 66045 Shackleton Limestone, Dick Formation, Douglas Conglomer- ate, and Starshot Formation (reviewed in Laird 1981). The Lower ERIN D. COLE Cambrian Shackleton Limestone throughout the Churchill Mountains represents only shallow-water carbonate shelf and peritidal deposits (Rees, Rowell, and Pratt 1987; Rees, Pratt, Department of Geoscience University of Nevada at Las Vegas and Rowell in press). The limestone breccia sequence at Crack- Las Vegas, Nevada 89154 ling Cwm (figure, block C), which tentatively was interpreted as a deep-water deposit in the Shackleton by Burgess and Lammerink (1979), we consider to be a younger, very proximal Stratigraphic and structural data collected during our 1987- alluvial fan accumulation. It is fractured, deformed, and faulted 1988 field season in the Churchill Mountains (figure) together against a highly cleaved and isoclinally folded argillite, which with isotopic and geochemical data necessitate a revision in in turn is juxtaposed to deformed Shackleton. The breccia is the stratigraphy of the pre-Devonian Paleozoic Byrd Group clast supported, matrix poor, and extremely poorly sorted with and a reinterpretation of the regional geological history. We clasts ranging from 0.5 centimeters to 10 meters. Most clasts conclude that there is no evidence for deep-water deposition are dark gray mottled or white fenestral limestones; cyano- in the Shackleton Limestone, that the Dick Formation is part bacteria-archaeocyathan boundstone clasts are very rare. Bed- of the basin-fill phase of sedimentation formed subsequent to ding within large blocks is obvious, but within the breccia the initial episode of Paleozoic deformation, and that there is sequence it can be traced laterally only a few meters. No fine- no evidence for volcanic activity in the area during deposition grained, marine basin or slope interbeds nor clasts derived of the group. Although not the focus of our field work, we from such occur in the sequence. This breccia sequence may 1988 REVIEW 23 159 160 V V Z% J7 +1 crac J kling - A% 0 5 165 -- 17 —J Km Mt I co Fig I/ Dick— \ L NP be - 7( Ross / N Ice Shelf \ .c fr Fig "-I U, H LI \ F H Ii. Darley A. )G Hills lie a 1 0 5 I 15Y Beacon Supergroup a Km p- Farrar Group 4.. \t Starspiot Formation + 4, Dick Formation b %^ Shack l.ton Limestone \ N 51 Douglas Conglomerate •e2. Fault Landing Cite P^ HE 0 Camp Snowmobile route 7n I>] Location of the two field areas between the Byrd and Nimrod glaciers in the central Transantarctic Mountains. The bold letters and numbers In 1C and 10 are localities visited during the 1987-1988 field season and are discussed in the text. The geology illustrated in C and D is generalized to show only outcrop distribution and major faults. The multiple phases of folding are not shown or implied. In C, outlines of nunataks A through F are approximated In part from pace-and-compass maps and oblique air photographs. Their scale bars equal ap- proximately 100 meters. In D, the geology is modified from Laird, Mansergh, and Chappell (1971). be correlative, at least in part, with the Douglas Conglomerate, C) interpreted as braid-plain deposits, is typically a massive, which elsewhere in the Churchill Mountains is of similar lith- crudely planar-, or trough-cross-stratified pebble-to-cobble ology (Rees and Rowell in press). conglomerate with thin interbedded cross-stratified and rip- The Douglas Conglomerate at locality M (figure, block D) pled sandstone. It is composed predominantly of limestone, unconformably overlies highly deformed Shackleton Lime- dolomite, and sandstone clasts with lesser amounts of mafic stone (Rees, Rowell, and Pratt 1987; Rowell et al. in press); volcanic and granitic clasts that collectively represent a recycled however, at its type locality (Locality B, figure, block C; Skinner orogen provenance (sensu Dickinson and Suczek 1979). 1964, 1965), it gradationally overlies the fine-grained Dick For- We interpret the Dick Formation to represent fine-grained mation. The Douglas at localities A, B, C, and I (figure, block fluvial to marginal marine deposits and to be genetically related 24 ANTARCTIC JOURNAL to the Douglas not the Shackleton. The Dick at its type locality This study has been supported by National Science Foundation (Locality B, figure, block C; Skinner 1964, 1965) is composed grants DPP 85-18157 and DPP 87-44459 to the University of of rippled and cross-bedded sandstones; abundant parallel- Nevada, Las Vegas, and DPP 85-19722 to the University of bedded shales with rare mudcracks and rare horizontal traces; Kansas. rippled siltstones; and, near its top, thin conglomerate beds. References Its style and sequence of deformation is similar to that recorded in the Douglas near Mount Hamilton (Rees et al. in press). Burgess, C.J., and W. Lammerink. 1979. Geology of the Shackleton The Dick at locality E (figure, block C) is tectonically juxtaposed Limestone (Cambrian) in the Byrd Glacier area. New Zealand Antarctic to the Shackleton Limestone along a folded, sheared, and prob- Record, 2, 12-16. ably faulted contact. At that locality, thin polymictic limestone Dickinson, W.R., and C. A. Suczek. 1979. Plate tectonics and sandstone conglomerates with compositions similar to those in the Doug- composition. American Association of Petroleum Geologists Bulletin, 63, las are interbedded with the Dick. These carbonate-rich beds 2164-2182. are depositionally unrelated to the Shackleton. Laird, M.G. 1981. Lower Palaeozoic rocks of Antarctica. In C.H. Hol- land (Ed.), Lower Paleozoic of the Middle East, Eastern and Southern Snow bounded outcrops of volcanics at localities 17 and J Africa, and Antarctica. New York: John Wiley and Sons Ltd. (figure, block C), initially included in the Dick Formation (Skin- Laird, M. G., G. D. Mansergh, and J.M.A. Chappell. 1971. Geology of ner 1964, 1965), are pillow basalts that have a minimum age the central Nimrod Glacier area, Antarctica. New Zealand Journal of of 586 ± 20 million years based on potasium/argon dates. As Geology and Geophysics, 14, 427-468. such, they are not related to the Byrd Group. Major, trace, Rees, MN., G.H. Girty, S.K. Panttaja, and P. Braddock. 1987. Multiple and rare-earth elemental data suggest that the basalts were phases of early Paleozoic deformation in the central Transantarctic generated by partial melting of mantle slightly enriched in light Mountains. Antarctic Journal of the U.S., 22(5), 33-35.
Load more

Recommended publications
  • HN.Tflrcitiici
    HN.TflRCiTiICi A NEWS BULLETIN published quarterly by the NEW ZEALAND ANTARCTIC SOCIETY (INC) 4 !*y/. A New Zealand/West German/American geological field party in Northern Victoria Land unloads equipment from a United States Navy ski-equipped Hercules at Crosscut Peak in the Millen Range. Antarctic Division photo \/nl»«• ■ 1ftIU, blf\I1U. ftO RegisteredWellington, Newat PostZealand, Office as Headquarters,a magazine. UCV/CII nfiromhor lUCI , 1 I Qfl/1oOH SOUTH GEORGIA SOUTH SANDWICH li' / S O U T H O R K N E Y I s ' \ e#2?KS /o Orcadas arg v rt FALKLAND Ij /6SignyluK y SajiMsA^^^qyoUiarevilaya > K 6 0 " W / SOUTH AMERICA * /' ,\ {/ Boiga / nJ^L^T. \w\ 4 s o u t h , * / w e d d e l l \ 3 S A / % T ^ & * ^ V SHETLAND J J!*, ,' / Hallev Bavof DRONNING MAUD LANO ENDERBY ^ / , s A V V ' ' / S E A u k T J C O A T S L d I / L A N D , , - Druzhnaya ^General Belgrano arg u s s r , < 6 V > ^ - " ^ ~ ^ I / K \ M a w s o n ANTARCTIC -tSS^ MAC ROBERTSON LAND\ '. *usi /PENINSULA'^ (sn map belowl ' 'Sobral arg Davis ausi L Siple. USA Amundsen-Scon OUEEN MARY LAND <!MimY ELLSWORTH i , J j U S S R LAND /x. ' / vostok° Vo s t o kussr/ u s s r / rrv > . MARIE BYRD Ice Shelf V>^ \^ / * L LAND \ W I L K E S L A N D ^ - / ' Rossr?#Vanda?' / y^\/ SEA IV^r/VICTORIA .TERRE A 7 ■ 4F&/ LMO \/ kOtU^y/ Ax ( G E O R G E V \ A .
    [Show full text]
  • Hnjtflrcilild
    HNjTflRCililD A NEWS BULLETIN published quarterly by the NEW ZEALAND ANTARCTIC SOCIETY (INC) Drillers on the Ross Ice Shelf last season used a new hot water system to penetrate fc. 416m of ice and gain access to the waters of the Ross Sea. Here the rig is at work on an access hole for a Norwegian science rproject. ' U . S . N a v y p h o t o Registered ol Post Office Headquarters, Vol. 8, No. 9. Wellington. New Zealand, as a magazine. SOUTH GEORGIA. •.. SOUTH SANDWICH Is' ,,r circle / SOUTH ORKNEY Is' \ $&?-""" "~~~^ / "^x AFAtKtANOis /^SiJS?UK*"0.V" ^Tl~ N^olazarevskayauss« SOUTH AMERICA / /\ ,f Borg°a ~7^1£^ ^.T, \60'E, /? cnirru „ / \ if sa / anT^^^Mo odezhnaya V/ x> SOUTH 9 .» /WEDDELL \ .'/ ' 0,X vr\uss.aT/>\ & SHETtAND-iSfV, / / Halley Bay*! DRONNING MAUD LAND ^im ^ >^ \ - / l s * S Y 2 < 'SEA/ S Euk A J COATSu k V ' tdC O A T S t d / L A N D ! > / \ Dfu^naya^^eneral Belgrano^RG y\ \ Mawson ANTARCTIC SrV MAC ROBERTSON LAND\ \ aust /PENINSULA'^ (see map below) Sobral arg / t Davis aust K- Siple ■■ [ U S A Amundsen-Scott / queen MARY LAND <JMirny AJELLSWORTH Vets') LAND °Vostok ussr MARIE BYRDNs? vice ShelA^ WIIKES tAND , ? O S S ^ . X V a n d a N z / SEA I JpY/VICTORIA .TERRE ,? ^ P o V t A N D V ^ / A D H J E j / V G E O R G E V L d , , _ / £ ^ . / ,^5s=:»iv-'s«,,y\ ^--Dumont d Urville france Leningradskaya \' / USSB_,^'' \ / -""*BALLENYIs\ / ANTARCTIC PENINSULA 1 Teniente Matienzo arg 2 Esperanza arg 3 Almirante Brown arg 4 Petrel arg 5 Decepcion arg.
    [Show full text]
  • Depositional History of Pre-Devonian Strata and Timing of Ross Orogenic Tectonism in the Central Transantarctic Mountains, Antarctica
    Depositional history of pre-Devonian strata and timing of Ross orogenic tectonism in the central Transantarctic Mountains, Antarctica Paul M. Myrow* Department of Geology, Colorado College, Colorado Springs, Colorado 80903, USA Michael C. Pope Department of Geology, Washington State University, Pullman, Washington 99164, USA John W. Goodge Department of Geological Sciences, Southern Methodist University, Dallas, Texas 75275, USA Woodward Fischer Department of Geology, Colorado College, Colorado Springs, Colorado 80903, USA Alison R. Palmer Institute for Cambrian Studies, 445 North Cedarbrook Road, Boulder, Colorado 80304-0417, USA ABSTRACT small fraction of its previous extent. The into trilobite- and hyolithid-bearing calcar- basal unit of the Byrd GroupÐthe predom- eous siltstone of the Starshot Formation A combination of ®eld mapping, detailed inantly carbonate ramp deposits of the and alluvial-fan deposits of the Douglas sedimentology, carbon isotope chemostra- Shackleton LimestoneÐrest with presumed Conglomerate. Trilobite fauna from the tigraphy, and new paleontological ®nds unconformity on the restricted Goldie For- lowermost siltstone deposits of the Starshot provides a signi®cantly improved under- mation. Paleontological data and carbon Formation date the onset of this transition standing of the depositional and tectonic isotope stratigraphy indicate that the Low- as being late Botomian. history of uppermost Neoproterozoic and er Cambrian Shackleton Limestone ranges The abrupt transition from the Shackle- lower Paleozoic strata of the central Trans- from lower Atdabanian through upper ton Limestone to a large-scale, upward- antarctic Mountains. On the basis of these Botomian. coarsening siliciclastic succession records data, we suggest revision of the existing This study presents the ®rst description deepening of the outer platform and then stratigraphy, including introduction of new of a depositional contact between the deposition of an eastward-prograding mo- formations, as follows.
    [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]
  • Tectonic Model for Development of the Byrd Glacier Discontinuity and Surrounding Regions of the Transantarctic Mountains During the Neoproterozoic – Early Paleozoic
    Published in: Fütterer, D K, Damaske, D, Kleinschmidt, G, Miller, H & Tessensohn, F (eds.), Antarctica: contributions to global earth sciences, Springer, Berlin, Heidelberg, New York, 45-54 http://dx.doi.org/10.1007/3-540-32934-X The original publication is available at http://www.springerlink.com see http://dx.doi.org/10.1007/3-540-32934-X_22 Data are available at: http://dx.doi.org/10.1594/PANGAEA.611703 Tectonic Model for Development of the Byrd Glacier Discontinuity and Surrounding Regions of the Transantarctic Mountains during the Neoproterozoic – Early Paleozoic Edmund Stump1 · Brian Gootee1 · Franco Talarico2 1 Department of Geological Sciences, Arizona State University, Tempe, Arizona AZ 85287-1404, USA 2 Dipartimento di Scienze della Terra, Università di Siena, Via del Laterino 8, 53100 Siena, Italy Abstract. The Byrd Glacier discontinuity is a major tectonic boundary crossing the Ross Orogen, with crystalline rocks to the north and primarily sedimentary rocks to the south. Most models for the tectonic development of the Ross Orogen in the central Transantarctic Mountains consist of two-dimensional transects across the belt, but do not address the major longitudinal contrast at Byrd Glacier. This paper presents a tectonic model centering on the Byrd Glacier discontinuity. Rifting in the Neoproterozoic produced a crustal promontory in the craton margin to the north of Byrd Glacier. Oblique convergence of a terrane (Beardmore microcontinent) during the latest Neoproterozoic and Early Cambrian was accompanied by subduction along the craton margin of East Antarctica. New data presented herein in support of this hypothesis are U-Pb dates of 545.7 ±6.8 Ma and 531.0 ±7.5 Ma on plutonic rocks from the Britannia Range, directly north of Byrd Glacier.
    [Show full text]
  • 1 Compiled by Mike Wing New Zealand Antarctic Society (Inc) Volume 1-36: Feb 2019 Vessel Names Are Shown Viz: “Aconcagua”. S
    ANTARCTIC1 Compiled by Mike Wing 12: 190, 19: 144, 22: 5, New Zealand Antarctic Society (Inc) Injury, 1: 340, 2: 118, 492, 3: 480, 509, 523, 4: 15, 8: 130, 282, 315, 317, 331, 409, Volume 1-36: Feb 2019 9: 12, 18, 19, 23, 125, 313, 394, 6: 17, 7: 6, 22, 11: 395, 12: 348, 18: 56, 19: 95, Vessel names are shown viz: “Aconcagua”. See also 22: 16, 32: 29, list of ship names under ‘Ships’. Ships All book reviews are shown under ‘Book Reviews’ ANARE, 8: 13, All Universities are shown under ‘Universities’ Argentine Navy, 1: 336, Aircraft types appear under ‘Aircraft’. “Bahia Paraiso” Obituaries & Tributes are shown under 'Obituaries', see Sinking 11: 384, 391, 441, 476, 12: 22, 200, also individual names. 353, 13: 28, Fishing, 30: 1, Vol 20 page numbers 27-36 are shared by both double Japanese, 24: 67, issues 1&2 and 3&4. Those in double issue 3&4 are NGO, 29, 62(issue 4), marked accordingly viz: 20: 4 (issue 3&4) Polar, 34, Soviet, 8: 426, Vol 27 page numbers 1-20 are shared by both issues Tourist ships, 20: 58, 62, 24: 67, 1&2. Those in issue 2 are marked accordingly viz. 27: Vehicles, (issue 2) NZ Snow-cat, 2: 118, US bulldozer, 1: 202, 340, 12: 54, Vol 29 pages 62-68 are shared by both issues 3&4. ACECRC, see Antarctic Climate & Ecosystems Duplicated pages in 4 are marked accordingly viz. 63: Cooperation Research Centre (issue 4). Acevedo, Capitan. A.O. 4: 36, Ackerman, Piers, 21: 16, Ackroyd, Lieut.
    [Show full text]
  • Gazetteer of the Antarctic
    NOIJ.VQNn OJ3ON3133^1 VNOI±VN r o CO ] ] Q) 1 £Q> : 0) >J N , CO O The National Science Foundation has TDD (Telephonic Device for the Deaf) capability, which enables individuals with hearing impairment to communicate with the Division of Personnel and Management about NSF programs, employment, or general information. This number is (202) 357-7492. GAZETTEER OF THE ANTARCTIC Fourth Edition names approved by the UNITED STATES BOARD ON GEOGRAPHIC NAMES a cooperative project of the DEFENSE MAPPING AGENCY Hydrographic/Topographic Center Washington, D. C. 20315 UNITED STATES GEOLOGICAL SURVEY National Mapping Division Reston, Virginia 22092 NATIONAL SCIENCE FOUNDATION Division of Polar Programs Washington, D. C. 20550 1989 STOCK NO. GAZGNANTARCS UNITED STATES BOARD ON GEOGRAPHIC NAMES Rupert B. Southard, Chairman Ralph E. Ehrenberg, Vice Chairman Richard R. Randall, Executive Secretary Department of Agriculture .................................................... Sterling J. Wilcox, member Donald D. Loff, deputy Anne Griesemer, deputy Department of Commerce .................................................... Charles E. Harrington, member Richard L. Forstall, deputy Henry Tom, deputy Edward L. Gates, Jr., deputy Department of Defense ....................................................... Thomas K. Coghlan, member Carl Nelius, deputy Lois Winneberger, deputy Department of the Interior .................................................... Rupert B. Southard, member Tracy A. Fortmann, deputy David E. Meier, deputy Joel L. Morrison, deputy Department
    [Show full text]
  • Downloaded 10/07/21 04:31 AM UTC JULY 2012 N I G R O E T a L
    2044 MONTHLY WEATHER REVIEW VOLUME 140 Case Study of a Barrier Wind Corner Jet off the Coast of the Prince Olav Mountains, Antarctica MELISSA A. NIGRO AND JOHN J. CASSANO Cooperative Institute for Research in Environmental Sciences, and Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder, Colorado MATTHEW A. LAZZARA Antarctic Meteorological Research Center, and Space Science and Engineering Center, University of Wisconsin—Madison, Madison, Wisconsin LINDA M. KELLER Department of Atmospheric and Oceanic Sciences, University of Wisconsin—Madison, Wisconsin (Manuscript received 30 September 2011, in final form 18 January 2012) ABSTRACT The Ross Ice Shelf airstream (RAS) is a barrier parallel flow along the base of the Transantarctic Moun- tains. Previous research has hypothesized that a combination of katabatic flow, barrier winds, and mesoscale and synoptic-scale cyclones drive the RAS. Within the RAS, an area of maximum wind speed is located to the northwest of the protruding Prince Olav Mountains. In this region, the Sabrina automatic weather station (AWS) observed a September 2009 high wind event with wind speeds in excess of 20 m s21 for nearly 35 h. The following case study uses in situ AWS observations and output from the Antarctic Mesoscale Prediction System to demonstrate that the strong wind speeds during this event were caused by a combination of various forcing mechanisms, including katabatic winds, barrier winds, a surface mesocyclone over the Ross Ice Shelf, an upper-level ridge over the southern tip of the Ross Ice Shelf, and topographic influences from the Prince Olav Mountains. These forcing mechanisms induced a barrier wind corner jet to the northwest of the Prince Olav Mountains, explaining the maximum wind speeds observed in this region.
    [Show full text]
  • Camenellan Tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, Palaeobiogeography, and Systematics
    Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics THOMAS M. CLAYBOURN, CHRISTIAN B. SKOVSTED, MARISSA J. BETTS, LARS E. HOLMER, LUCY BASSETT-BUTT, and GLENN A. BROCK Claybourn, T.M., Skovsted, C.B., Betts, M.J., Holmer, L.E., Bassett-Butt, L., and Brock G.A. 2021. Camenellan tom- mo tiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics. Acta Palaeontologica Polonica 66 (1): 207–229. Cambrian Series 2 shelly fossils from thick carbonate successions in East Antarctica have received limited systematic treatment through the 20th century. Described here are the East Antarctic camenellan tommotiids from the Shackleton Limestone in the Central Transantarctic Mountains and the Schneider Hills limestone in the Argentina Range. This material comes from both newly sampled collections and incompletely described material from older collections. The assemblage supports correlation to the Dailyatia odyssei Zone and Pararaia janeae Trilobite Zone of South Australia, with the newly examined specimens of Dailyatia decobruta from the Shackleton Limestone providing direct correlation to the Mernmerna Formation of the Ikara-Flinders Ranges and White Point Conglomerate of Kangaroo Island. These East Antarctic assemblages include five species referred to Dailyatia, in addition to an undetermined kennardiid species and fragments of the problematic Shetlandia multiplicata. The results further corroborate the notion that fossiliferous carbonate clasts found on King George Island were sourced from the same carbonate shelf as the Shackleton Limestone, with the taxon S. multiplicata found in both units. The Schneider Hills limestone in the Argentina Range has yielded sclerites of Dailyatia icari sp.
    [Show full text]
  • Geology & Geophysics of the Koonenberry Belt, Far Western New
    Geology & geophysics of the Koonenberry Belt, far western New South Wales, and eastern Australian correlates: Part II Delamerian Fold-Thrust Belts in eastern Australia Nicholas G. Direen Clv ic-1-0(0-s B.Sc (Hons) (UTas) A thesis submitted in fulfilment of the requirements of the degree of Doctor of Philosophy at the University of Tasmania, Hobart, Australia February 1999 198 PART 2: DELAMERIAN FOLD-THRUST BELTS IN EASTERN AUSTRALIA Chapter 9: Fleurieu "Arc", South Australia 9.1 Adelaide Fold-Thrust Belt, Delamerian type area. Possible correlations with NSW 9.2 Truro Volcanics: structure, stratigraphy, tectonic affinity. Review. 9.3 Petrology & geochemistry 9.4 Relationship to Koonenberty Belt (MA V) 9.5 Kanmantoo Group: stratigraphy, structure, tectonic affinity. Review. 9.6 Sedimentology 9.7 Overall structural and magmatic style of the Adelaide Fold Belt. 199 Chapter 9: Fleurieu "Arc", South Australia 9.1 Adelaide Fold-Thrust Belt, Delamerian type area. Possible correlations with the Koonenberry Fold-Thrust Belt. Part 1 of this study has shown that the Koonenberry Belt-Bancannia Trough region of far north-western New South Wales is a polydeformed fold and thrust belt which underwent major compressive tectonism during the Late Cambrian and again during the Silurian. The earlier of these two deformations has been correlated with the Delamerian Orogeny in South Australia, following the conclusions of Mills (1992) that these deformations are part of larger orogenic events. The Delamerian Orogeny is further correlated with the Tyennan Orogeny of Tasmania (Turner et al., 1998) and Ross Orogeny in Antarctica (Flottmann et al., 1993). The Delamerian Orogeny was originally defined by Thompson (1969) as a Late Cambrian to Early Ordovician deformation, with several discrete "movements".
    [Show full text]
  • Early Cambrian Molluscs from Glacial Erratics of King George Island, West Antarctica
    vol. 24, no. 3–4, pp. 181–216, 2003 Early Cambrian molluscs from glacial erratics of King George Island, West Antarctica Ryszard WRONA Instytut Paleobiologii, PAN, ul. Twarda 51/55, 00−818 Warszawa, Poland <[email protected]> ABSTRACT: Molluscan fossils accompanied by familiar SSF have been recovered from Early Cambrian limestone erratics in the Early Miocene glaciomarine Cape Melville For− mation of King George Island, West Antarctica. The molluscan fauna comprises the hyoliths Conotheca, Microcornus, Parkula, Hyptiotheca,“Hyolithes”, the helcionelloids ?Pararacornus, Yochelcionella, Anabarella, the low dextrally coiled Pelagiella and the high helically coiled Beshtashella, as well as the problematic mollusc Cupitheca. Most of described species are recorded here for the first time from Antarctica. The lithological and fossil contents of the erratics are almost the same as from autochthonous successions the Shackleton Limestone in the Argentina Range and Transantarctic Mountains. Early Cam− brian outcrops around the Weddell Sea are a probable source of the erratic boulders. The Antarctic fauna is very similar to that from uppermost Botomian and Toyonian carbonate deposits in the Cambrian Basins of South Australia. These faunal and facies similarities be− tween Antarctica and Australia confirm their neighbouring position and common biotic and basin evolution on the Cambrian Gondwana margin. Key words: Antarctica, King George Island, Cambrian, Hyolitha, Helcionelloida, Gondwana. Introduction The fossil assemblage recovered from Early
    [Show full text]
  • Sedimentologic, Mineralogic, and Geochemical Evaluation of the Provenance and Paleoclimatic Record of Permian Mudrocks from the Beardmore Glacier Area, Antarctica
    Order Number 9307776 Sedimentologic, mineralogic, and geochemical evaluation of the provenance and paleoclimatic record of Permian mudrocks from the Beardmore Glacier area, Antarctica Homer, Timothy Charles, Ph.D. The Ohio State University, 1992 UMI 300 N. Zeeb Rd. Ann Arbor, MI 48106 SEDIMENTOLOGIC, MINERA LOGIC, AND GEOCHEMICAL EVALUATION OF THE PROVENANCE AND PALEOCLIMATIC RECORD OF PERMIAN MUDROCKS FROM THE BEARDMORE GLACIER AREA, ANTARCTICA DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of the Ohio State University By Timothy C. Homer, B.S., M.S. ***** The Ohio State University 1992 Dissertation Committee: Approved By: Dr. Lawrence A. Krissek Dr. James W. Collinson Dr. Gunter Faure Advisor Department of Dr. David H. Elliot Geological Sciences Copyright by Timothy C. Homer 1992 ACKNOWLEDGEMENTS I wish to thank the members of my committee for their guidance during my work at Ohio State. Their critical review during early phases of the project helped shape my ideas, and resulted in a better dissertation. Special appreciation is extended to Larry Krissek for offering sound scientific advice when I needed help, and letting me progress on my own when I had an idea to explore. I also acknowledge the financial support and long term guidance given by Jim Collinson. This work was funded by National Science Foundation Grants DPP 84-18354 and DPP-8817023. Additional financial assistance was obtained through an Arco Oil and Gas Company research grant, the Shell Oil Company Fellowship and research grant at The Ohio State University, and a Geological Society of America research grant.
    [Show full text]