DOCSLIB.ORG

Geological Field Investigation of STEPHEN J. BOYER Dufek Intrusion U.S

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geological Field Investigation of STEPHEN J. BOYER Dufek Intrusion U.S G 2389 This interpretation is supported by an argon isochron ported by National Science Foundation grants (in the Pecora Escarpment, 1962-63), GA 222 (on the plot of 40Ar/36Ar and 40K/36Ar values (R. W. Kistler, un- AG 238 (in the Cordiner published data, 1978). The pyroxene shows much Dufek intrusion, 1965-66), and greater optical homogeneity than in the Dufek intrusion. Peaks, 1973-74) to the U.S. Geological Survey. The best estimate for the age of the sills is considered References to be the average of the mineral pair showing the most Elliot, D. H., R. j. Fleck, and J. F. Sutter. In press. K-Ar dating concordant and, more importantly, the youngest ages of of the Ferrar Group, central Transantarctic Mountains. In all analyzed pairs: 178.9 ± 4.5 million years (obtained Geology of the Central Transantarctic Mountains, eds. M. D. from a plagioclase age of 177.7 ± 4.5 million years and Turner and J . F. Splettstoesser. Antarctic Research Series, a pyroxene age of 180.0 ± 4.5 million years). Memoir. Washington, D.C.: American Geophysical Union. Analysis of a coexisting pyroxene-plagioclase pair Ford, A. B. 1972. The Weddell orogeny—latest Permian to from a dike in the Cordiner Peaks yielded discordant early Mesozoic deformation at the Weddell Sea margin of apparent ages of 307.9 ± 7.7 million years for pyroxene the Transantarctic Mountains. In Antarctic Geology and Geo- and 168.8 ± 4.2 million years for plagioclase. The pla- physics, ed. R. J . Adie, pp. 419-25. Olso, Norway: Univer- sitetsforlaget. gioclase age is considered to provide the best estimate Ford, A. B. 1976. Stratigraphy of the layered gabbroic Dufek for the dikes age, in that the pyroxene, which is opti- intrusion. Antarctica. U.S. Geological Survey Bulletin, no. cally homogeneous, is inferred to contain excess argon. 1405—D. The above results indicate that the basaltic magmatism Ford, A. B., D. L. Schmidt, and W. W. Boyd, Jr. 1978. Geologic that produced the dikes and sills and the Dufek intru- map of the Davis Valley Quadrangle and Part of the Cordiner sion in the Pensacola Mountains occurred over a narrow Peaks Quadrangle, Pensacola Mountains, Antarctica (1:250,000 time interval in the Early Jurassic. The bodies are cor- scale). U.S. Geological Survey Map A—b. Grindley, G. W. 1963. The geology of the Queen Alexandra related with the Ferrar Group in other parts of the Range, Beardmore. Glacier, Ross Dependency, Antarctica: Transantarctic Mountains (Elliot, Fleck, and Sutter, in With notes on the correlation of Gondwana sequences. New press) on the basis of age equivalence and close chemical Zealand Journal of Geology and Geophysics, 6: 307-47. comparisons (A. B. Ford, unpublished data, 1978). The Himmelberg, G. R., and A. B. Ford. 1976. Pyroxenes of the age of the Dufek intrusion reported here also provides Dufek intrusion, Antarctica. journal of Petrology, 17: 219-43. an upper age limit of Early Jurassic for the latest major Kistler, R. W., and F. C. W. Dodge. 1966. Potassium-argon ages orogeny in the Pensacola Mountains, during which rocks of coexisting minerals from pyroxene-bearing granitic rocks as young as Permian were strongly folded (Ford, 1972). in the Sierra Nevada, California. Journal of Geophysical Re- The fieldwork on which this study is based was sup- search, 71(8): 2157-61. Geological field investigation of STEPHEN J. BOYER Dufek intrusion U.S. Geological Survey Denver, Colorado 80225 ARTHUR B. FORD Between 4 November and 20 December 1978, the au- thors carried out geological field studies of the layered U.S. Geological Survey gabbroic Dufek intrusion (Ford, 1976). This work con- Menlo Park, California 94025 tinued the detailed investigation of the unusually large igneous complex that was started in the western Dufek Massif, in the lower part of the body, in the summer of RICHARD L. REYNOLDS 1976-77 (Ford et al., 1977). In 1978, the authors focused on the iron-enriched U.S. Geological Survey upper part of the body, in the southern Forrestal Range. Denver, Colorado 80225 During November, fieldwork was done by snowmobile and ski traverses from a tent camp in May Valley. Dur- ing December, work was also continued in the Dufek Massif from tent camps located on the Sallee Snowfield CARL HUIE and near Aughenbaugh Peak. The purpose of this fieldwork was to investigate ques- U.S. Geological Survey tions raised by laboratory and office studies following a Menlo Park, California 94025 1965-66 reconnaissance of the complex (Ford and Boyd, 1968). Although topographic base maps had not been available at the time of that reconnaissance, the data obtained were adequate for compilation of two recently published 1:250,000-scale geologic maps of the body (Ford, Schmidt, and Boyd, 1978; Ford et al., 1978). ing abundant included blocks of noncumulus anorthos- In the 1978-79 study, most of the larger outcrop ite and leucogabbro was found to occur at about the areas in the Forrestal Range were mapped at a scale of level of the chemical reversal. The apparent chaotic na- 1:25,000. This larger-scale mapping was needed to de- ture of the blocks (figure 3) gives the layer the appear- termine the stratigraphy and distribution of the many ance of a megabreccia in sedimentary rocks. A distinct stratiform units of anorthositic, leucogabbroic, and py- angular discordance of up to about 10 degrees was roxenitic cumulates interlayered within the mostly gab- found to exist between this horizon and the more steeply broic cumulates (figure 1). The term "cumulate" is dipping layered cumulates below. This angular relation used for igneous rocks formed by accumulative pro- occurs regionally across the body and is most pro- cesses involving currents or settling under gravity. Evi- dence for current erosion and deposition is strikingly displayed at a number of places by channellike struc- tures (figure 2) analogous to cut-and-fill channels in sed- imentary rock sequences. Laboratory studies (Himmelberg and Ford, 1976, 1977) show that mineral compositions vary systemati- cally and gradually upward through the complex to a level about one kilometer below the top, at which point the chemical trends show a sharp reversal before again resuming a differentiation trend similar to that below. Possible origins of this reversal include contamination; a major convective disturbance bringing in magma from another part of the chamber; and the injection of a large volume of new magma at a late stage of the bodys con- solidation. As the origin of the reversal is of great im- portance in interpreting the differentiation record, this was one of the principal issues studied during the 1978- 79 fieldwork. Figure 2. Anorthosite-filled channel In gabbrolc cumulates on Mount Stephens, Forrestal Range. The central part of the During the mapping, a major unit of gabbro contain- channel Is more than 15 meters thick. v ww EL wpq A Figure 1. Layer of leucogabbrolc cumulate, about 7 meters thick, in dark Figure 3. Anorthosite "megabreccia" layer, north rim of Sar- gabbrolc cumulate near May Valley, Forrestal atoga Table, Forrestal Range. (Note figure In lower center Range. Magnetite is abundant near the base of the layer. for scale.) FEll nounced in the axial part of the synform of the intru- References sion. It appears to be somewhat analogous to a regional Boyer, S. J . 1979. Glacial geologic observations in Dufek Massif angular unconformity in sedimentary rock sequences. and Forrestal Range. Antarctic Journal of the United States (this The discordance is tentatively interpreted as being the issue). result of strong axial subsidence or of lopolithic sagging, Ford, A. B. 1976. Stratigraphy of the layered gabbroic Dufek perhaps related to magma withdrawal from depth. If so, intrusion, Antarctica. U.S. Geological Survey Bulletin, no. the chemical reversal described above may be related to 1405-D. high-level emplacement of this "new" magma and mix- Ford, A. B. and W. W. Boyd, Jr. 1968. The Dufek intrusion, ing with residual magma of the chamber. The subsi- a major stratiform gabbroic body in the Pensacola Moun- dence was a comparatively sudden, perhaps cata- tains, Antarctica. 23rd International Geological Congress, Pra- gue. Proceedings, 2: 213-28. strophic, event resulting in the tearing loose from either Ford, A. B., Christine Carlson, G. K. Czamanske, W. H. Nelson, the chamber walls or roof of large blocks of anorthosite and C. J . Nutt. 1977. Geological studies of the Dufèk intru- and leucogabbro that were then spread as a basal me- sion, Pensacola Mountains, 1976-77. Antarctic Journal of the gabreccia deposit many kilometers across the chamber United States, 12(4): 90-92. floor. Several stratigraphic sections of this part of the Ford, A. B., D. L. Schmidt, and W. W. Boyd, Jr. 1978. Geologic body were measured and sampled in detail for addi- Map of the Davis Valley Quadrangle and Part of the Cordiner tional laboratory studies on the nature of the chemically Peaks Quadrangle, Pensacola Mountains, Antarctica (1:250,000 reversed zone and of mineralogic changes during the scale). U.S. Geological Survey Map A-b. Ford, A. B., D. L. Schmidt, W. W. Boyd, Jr., and W. H. Nelson. final crystallization stages of the body. 1978. Geologic Map of the Saratoga Table Quadrangle, Pensacola Studies of soils developed on a variety of bedrock lith- Mountains, Antarctica (1:250,000 scale). U.S. Geological Sur- ologies and of the glacial geologic history of the region vey Map A-9. also were carried out during the summer of 1978-79 Himmelberg, G. R., and A. B. Ford. 1976. Pyroxenes of the (Boyer, 1979). Dufék intrusion, Antarctica. journal o/Petrology, 17: 219-43. The authors work on this project has been supported Himmelberg, G.
Load more

Recommended publications
  • Microorganisms in Antarctic Desert Rocks from Dry Valleys and Dufek
    onies per gram of soil). Also, time did not permit a second show the striking result that PYSA enabled development of plating. greater numbers of microorganisms than TSSA. Finally, only In most instances the appreciably higher numbers of col- 13 of the 138 Dufek Massif soil spread plates had any fungi, onies on PYSA plates were due to numerous small mucoid and by far most of the microorganisms were heterotrophic pink colonies, only a relative few of which developed on TSSA aerobic bacteria. plates. We plan to examine these isolates to better under- Cameron and Ford (1974) report aerobic bacteria of 0, stand their physiology. Similar pink colonies also were not less than 10, and 10 per gram of soil collected from Mount common in soils from the dry valleys of southern Victoria Lechner and 50, 250, and 1,800 per gram of soil collected Land grown on both TSSA and PYSA plates, although the soils from Cordiner Peaks. Only in two of 23 soils did our aerobic were collected, stored, and processed similarly to those from bacteria exceed 1,800 per gram of soil when TSSA medium the Dufek Massif. Further, a more extensive survey of was used. These results suggest that TSSA and probably the microbial abundance in soils of New Harbor, Barwick Tripticase soy agar (without soil extract) as used by Valley, and other locations in the dry valleys of southern Cameron and Ford (1974) may not be a good medium for Victoria Land during the 1976-1977 field season failed to microorganisms native to the remote Antarctic soils of the Pensacola Mountains and the Dufek Massif.
    [Show full text]
  • Geologic Map of the Davis Valley Quadrangle and Part of the Cordiner Peaks Quadrangle, Pensacola Mountains, Antarctica
    -0 DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEOLOGIC MAP OF THE DAVIS VALLEY QUADRANGLE AND PART OF THE CORDINER PEAKS QUADRANGLE, PENSACOLA MOUNTAINS, ANTARCTICA By Arthur B. Ford, Dwight L. Schmidt, and Walter W. Boyd, Jr. Prepared by the U.S. GEOLOGICAL SURVEY under the auspices of the NATIONAL SCIENCE FOUNDATION -N V'l 0 0 0 0 U.S. ANTARCTIC RESEARCH PROGRAM MAP Published by the U.S. Geological Survey, 1978 G GEOLOGIC MAP SYMBOLS COMMONLY USED ON MAPS OF THE UNITED STATES GEOLOGICAL SURVEY (Special symbols are shown in explanation) Contact-Dashed where approximately Strike and dip of beds-Ball indicates located; short dashed where inferred; top of beds known from sedimentary dotted where concealed structures _1!_ Inclined EB Horizontal Contact-Showing dip; well exposed at -+- Vertical Overturned triangle -..J!. Strike and dip of foliation Fault-Dashed where approximately located; short dashed where inferred; ~ Inclined -+·Vertical +Horizontal dotted where concealed Strike and dip of cleavage Fault, showing dip-Ball and bar on ~ Inclined ~Vertical +Horizontal downthrown side Bearing and plunge of lineation Normal fault-Hachured on down­ '~Inclined • Vertical - Horizontal thrown side Strike and dip of joints Fault-Showing relative horizontal -~ Inclined --Vertical +Horizontal movement Note: Planar symbols (strike and dip + + + + + + Thrust fault-Sawteeth on upper plate of beds, foliation or schistosity, and cleav­ age) may be combined with linear symbols to record data observed at ~ Anticline-Showing direction of plunge; same locality by superimposed symbols dashed where approximately located; at point of observation. Coexisting dotted where concealed planar symbols are shown intersecting at point of observation.
    [Show full text]
  • Geological Studies of the Dufek Intrusion, Pensacola Mountains
    study of the Pensacola Mountains, for much helpful discus- was established at the LC-130 ski-plane landing site near sion of the geologic relations here reported. Walker Peak, from which motor toboggan and ski traverses This research is supported by National Science Founda- were made to sites of investigations. The massif and nearby tion interagency agreement DDP 76-21663 with the nunataks are underlain by layered mafic igneous rocks of Geologic Division, U.S. Geological Survey. cumulus origin that make up the lower part of the Dufek intrusion, a Jurassic stratiform complex of immense size in the northern third of the Pensacola Mountains. References The U.S. Geological Survey (USGS) made reconnaissance studies using Army helicopters of all outcropping parts of the intrusion in the summer 1965-1966. This work showed Clarkson, P.D. 1972. Geology of the Shackleton Range: a that all of the Forrestal Range, located about 50 kilometers preliminary report. British Antarctic Survey Bulletin, 31: 1-15. southeast of Dufek Massif, is also underlain by part—the Craddock, Campbell. 1970. Tectonic map of Antarctica. Antarctic iron-enriched upper part - of the Dufek intrusion (Ford and Map Folio Series, 12: plate XXI. Boyd, 1968), and that the body probably has an area of at Ford, A.B. 1972. The Weddell orogeny—latest Permian to early least 24,000 square kilometers (Behrendt et al., 1974). As Mesozoic deformation at the Weddell Sea margin of the Trans. the thickness is estimated to be on the order of 8 to 9 antarctic Mountains. In: Antarctic Geology and Geophysics kilometers (Ford, 1976), the original magma volume may (Adie, R.J., editor).
    [Show full text]
  • Davis Valley and Forlidas Pond, Dufek Massif
    Measure 2 (2005) Annex D Management Plan for Antarctic Specially Protected Area No. 119 DAVIS VALLEY AND FORLIDAS POND, DUFEK MASSIF 1. Description of Values to be Protected Forlidas Pond (82°27'28"S, 51°16'48"W) and several ponds along the northern ice margin of the Davis Valley (82°27'30"S, 51°05'W), in the Dufek Massif, Pensacola Mountains, were originally designated as a Specially Protected Area through Recommendation XVI-9 (1991, SPA No. 23) after a proposal by the United States of America. The Area was designated on the grounds that it “contains some of the most southerly freshwater ponds known in Antarctica containing plant life” which “should be protected as examples of unique near-pristine freshwater ecosystems and their catchments”. The original Area comprised two sections approximately 500 metres apart with a combined total area of around 6 km2. It included Forlidas Pond and the meltwater ponds along the ice margin at the northern limit of the Davis Valley. The site has been rarely visited and until recently there has been little information available on the ecosystems within the Area. This Management Plan reaffirms the original reason for designation of the Area, recognizing the ponds and their associated plant life as pristine examples of a southerly freshwater habitat. However, following a field visit made in December 2003 (Hodgson and Convey, 2004) the values identified for special protection and the boundaries for the Area have been expanded as described below. The Davis Valley and the adjacent ice-free valleys is one of the most southerly ‘dry valley’ systems in Antarctica and, as of May 2005, is the most southerly protected area in Antarctica.
    [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]
  • November 1960 I Believe That the Major Exports of Antarctica Are Scientific Data
    JIET L S. Antarctic Projects OfficerI November 1960 I believe that the major exports of Antarctica are scientific data. Certainly that is true now and I think it will be true for a long time and I think these data may turn out to be of vastly, more value to all mankind than all of the mineral riches of the continent and the life of the seas that surround it. The Polar Regions in Their Relation to Human Affairs, by Laurence M. Gould (Bow- man Memorial Lectures, Series Four), The American Geographiql Society, New York, 1958 page 29.. I ITOJ TJM II IU1viBEt 3 IToveber 1960 CONTENTS 1 The First Month 1 Air Operations 2 Ship Oper&tions 3 Project MAGNET NAF McMurdo Sounds October Weather 4 4 DEEP FREEZE 62 Volunteers Solicited A DAY AT TEE SOUTH POLE STATION, by Paul A Siple 5 in Antarctica 8 International Cooperation 8 Foreign Observer Exchange Program 9 Scientific Exchange Program NavyPrograrn 9 Argentine Navy-U.S. Station Cooperation 9 10 Other Programs 10 Worlds Largest Aircraft in Antarctic Operation 11 ANTARCTICA, by Emil Schulthess The Antarctic Treaty 11 11 USNS PRIVATE FRANIC 3. FETRARCA (TAK-250) 1961 Scientific Leaders 12 NAAF Little Rockford Reopened 13 13 First Flight to Hallett Station 14 Simmer Operations Begin at South Pole First DEEP FREEZE 61 Airdrop 14 15 DEEP FREEZE 61 Cargo Antarctic Real Estate 15 Antarctic Chronology,. 1960-61 16 The 'AuuOiA vises to t):iank Di * ?a]. A, Siple for his artj.ole Wh.4b begins n page 5 Matera1 for other sections of bhis issue was drawn from radio messages and fran information provided bY the DepBr1nozrt of State the Nat0na1 Academy , of Soienoes the NatgnA1 Science Fouxidation the Office 6f NAval Re- search, and the U, 3, Navy Hydziograpbio Offioe, Tiis, issue of tie 3n oovers: i16, aótivitiès o events 11 Novóiber The of the Uxitéd States.
    [Show full text]
  • (ASPA) No. 119 DAVIS VALLEY and FORLIDAS POND
    Measure 6 (2010) Annex Management Plan for Antarctic Specially Protected Area (ASPA) No. 119 DAVIS VALLEY AND FORLIDAS POND, DUFEK MASSIF, PENSACOLA MOUNTAINS (51° 05' W, 82° 29' S) Introduction Davis Valley and Forlidas Pond Antarctic Specially Protected Area (ASPA) is situated within the Dufek Massif, Pensacola Mountains at 51°4'53"W, 82°29'21"S. Approximate area: 57.3 km2. The primary reason for the designation of the Area is that it contains some of the most southerly freshwater ponds with plant life known to exist in Antarctica, which represent unique examples of near-pristine freshwater ecosystems and their catchments. The geomorphology of the Area represents a unique scientific resource for the reconstruction of previous glacial and climatic events. As a consequence of its extreme remoteness and inaccessibility, the Area has experienced very little human activity and with the total number of visitors estimated to be less than 50 people. As a result, the Area has outstanding potential as a scientific reference site. Furthermore, the Area possesses outstanding wilderness and aesthetic values. The Area is one of the most southerly ‘dry valley’ systems in Antarctica and, as of March 2010, is the most southerly Antarctic Specially Protected Area (ASPA) in Antarctica. The Area was originally proposed by the United States of America and adopted through Recommendation through Recommendation XVI-9 (1991, SPA No. 23) and included Forlidas Pond (82°27'28"S, 51°16'48"W) and several ponds along the northern ice margin of the Davis Valley. The boundaries of the Area were extended to include the entire ice-free region centered on the Davis Valley through Measure 2 (2005).
    [Show full text]
  • Geology of the Nelson Limestone, Postel Nunatak, Patuxent Range, Antarctica KEVIN RAY EVANS1, LAWRENCE W
    Antarctic Science 30(1), 29–43 (2018) © Antarctic Science Ltd 2017. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. doi:10.1017/S0954102017000396 Geology of the Nelson Limestone, Postel Nunatak, Patuxent Range, Antarctica KEVIN RAY EVANS1, LAWRENCE W. MCKENNA III2, BRUCE S. LIEBERMAN3, WESLEY DONALD WEICHERT1 and KENNETH G. MACLEOD4 1Department of Geography, Geology & Planning, Missouri State University, 901 S. National Avenue, Springfield, MO 65897, USA 2Department of Physics & Earth Science, Framingham State University, 100 State Street, PO Box 9101, Framingham, MA 01701-9101, USA 3Department of Ecology & Evolutionary Biology & Biodiversity Institute, 1345 Jayhawk Boulevard, The University of Kansas, Lawrence, KS 66045, USA 4Department of Geological Sciences, University of Missouri – Columbia, 101 Geological Sciences Building, Columbia, MO 65211, USA [email protected] Abstract: Postel Nunatak in the Patuxent Range has been previously mapped as Nelson Limestone but there was no biostratigraphic support for that interpretation until now. We confirm that limestone exposures at Postel Nunatak are at least partly correlated with the Nelson Limestone of the Neptune Range, 160 km north-east, and are not correlative with the lower Cambrian Schneider Hills Limestone of the Argentina Range. Upper beds have yielded the trilobites Suludella? davnii Palmer & Gatehouse, 1972 and Solenopleura pruina Palmer & Gatehouse, 1972, which provide a basis for assignment to Cambrian Series 3 (late middle Cambrian), within the Drumian or lower Guzhangian stages. Limestone beds were deposited in a shallow marine setting, ranging from supratidal to lagoonal facies with rare subtidal intervals.
    [Show full text]
  • US Geological Survey Polar Research Symposium
    U.S. Geological Survey Polar Research Symposium­ Abstracts with Program GEOLOGICAL SURVEY CIRCULAR 911 f I .. t I ,. r v· ~ r u. 1aI l In celebration of the 1OOth anniversary of the First International Polar Year, the 50th anniversary of the Second International Polar Year, and the 25th anniversary of the International Geophysical Year The U.S. Geological Survey Polar Research Symposium celebrates the lOOth and 50th anniversaries of the First and Second International Polar Years, respectively, and the 25th anniversary of the International Geophysical Year. The symposium is part of a series of worldwide activities that include lectures, symposia, and exhibits organized at the request of the International Council of Scientific Unions. The International Polar Years and especially the Interna­ tional Geophysical Year profoundly influenced the evolution of geophysics and served as models for international multidisciplinary cooperation in science. U.S. Geological Survey Polar Research Symposium­ Abstracts with Program GEOLOGICAL SURVEY CIRCULAR 9 l l In celebration of the 1OOth anniversary of the First International Polar Year, the 50th anniversary of the Second International Polar Year, and the 25th anniversary of the International Geophysical Year October 12-14, 1983 United States Department of the Interior JAMES G. WATT, Secretary Geological Survey Dallas L. Peck, Director Free on application to Distribution Branch, Text Products Section, U. S. Geological Survey, 604 South Pickett Street, Alexandria, VA 22304 CONTENTS Page Progrmn--------------------------------------------------------------------
    [Show full text]
  • Geology of the Nelson Limestone, Postel Nunatak, Patuxent Range, Antarctica KEVIN RAY EVANS1, LAWRENCE W
    Antarctic Science 30(1), 29–43 (2018) © Antarctic Science Ltd 2017. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. doi:10.1017/S0954102017000396 Geology of the Nelson Limestone, Postel Nunatak, Patuxent Range, Antarctica KEVIN RAY EVANS1, LAWRENCE W. MCKENNA III2, BRUCE S. LIEBERMAN3, WESLEY DONALD WEICHERT1 and KENNETH G. MACLEOD4 1Department of Geography, Geology & Planning, Missouri State University, 901 S. National Avenue, Springfield, MO 65897, USA 2Department of Physics & Earth Science, Framingham State University, 100 State Street, PO Box 9101, Framingham, MA 01701-9101, USA 3Department of Ecology & Evolutionary Biology & Biodiversity Institute, 1345 Jayhawk Boulevard, The University of Kansas, Lawrence, KS 66045, USA 4Department of Geological Sciences, University of Missouri – Columbia, 101 Geological Sciences Building, Columbia, MO 65211, USA [email protected] Abstract: Postel Nunatak in the Patuxent Range has been previously mapped as Nelson Limestone but there was no biostratigraphic support for that interpretation until now. We confirm that limestone exposures at Postel Nunatak are at least partly correlated with the Nelson Limestone of the Neptune Range, 160 km north-east, and are not correlative with the lower Cambrian Schneider Hills Limestone of the Argentina Range. Upper beds have yielded the trilobites Suludella? davnii Palmer & Gatehouse, 1972 and Solenopleura pruina Palmer & Gatehouse, 1972, which provide a basis for assignment to Cambrian Series 3 (late middle Cambrian), within the Drumian or lower Guzhangian stages. Limestone beds were deposited in a shallow marine setting, ranging from supratidal to lagoonal facies with rare subtidal intervals.
    [Show full text]
  • Geologitc Majp of the Saratoga Tajble Quadrangle, Pensacola Mountains, Antarctica
    DEJP> A.R TMENT Of THE INTERIOR !UNHTJED STATES GEOLOGICAL SURVEY GEOLOGITC MAJP OF THE SARATOGA TAJBLE QUADRANGLE, PENSACOLA MOUNTAINS, ANTARCTICA By Arthur B. Forrd, Dwight L. Schmidt, Walter W. Boyd 9 Jrr., and Willis H. Nelson Prepared by the U.S. GEOLOGHCAL SURVEY under the auspices of the NATIONAL SCIENCE FOUNDATITON - t-J (.1\ 0 b 0 0 U.S. ANTARCTIC RESEARCH PROGRAM MAP Published by the U.S. Geological Survey, 1978 G GEOLOGIC MAP SYMBOLS COMMONLY USED ON MAPS OF THE UNITED STATES GEOLOGICAL SURVEY (Special symbols are shown in explanation) Contact-Dashed where approximately Strike and dip of beds-Ball indicates located; short dashed where inferred; top of beds known from sedimentary dotted where concealed structures _!!!_ Inclined EB Horizontal Contact-Showing dip; well exposed at -t- Vertical -.;:.Overturned triangle Strike and dip of foliation Fault-Dashed where approximately located; short dashed where inferred; .31?_ Inclined --+- Vertical +Horizontal dotted where concealed Strike and dip of cleavage Fault, showing dip-Ball and bar on ~ Inclined 1--f Vertical +Horizontal downthrown side Bearing and plunge of lineation -,--..,....--.,.-~"""T"-...-- Normal fault-Hachured on down­ '~Inclined • Vertical -Horizontal thrown side Strike and dip of joints Fault-Showing relative horizontal -~ Inclined --Vertical +Horizontal movement Note: Planar symbols (strike and dip + + + + + + Thrust fault-Sawteeth on upper plate of beds, foliation or schistosity, and cleav­ age) may be combined with linear symbols to record data observed at • Anticline-Showing direction of plunge; same locality by superimposed symbols dashed where approximately located; at point of observation. Coexisting dotted where concealed planar symbols are shown intersecting at point of observation.
    [Show full text]
  • The Antarctic Treaty Cm 7166
    Miscellaneous No. 6 (2007) The Antarctic Treaty Measures adopted at the Twenty-eighth Consultative Meeting held at Stockholm 6 – 17 June 2005 Presented to Parliament by the Secretary of State for Foreign and Commonwealth Affairs by Command of Her Majesty July 2007 Cm 7166 £22.50 © Crown copyright 2007 The text in this document (excluding the Royal Arms and departmental logos) may be reproduced free of charge in any format or medium providing it is reproduced accurately and not used in a misleading context. The material must be acknowledged as Crown copyright and the title of the document specified. Any enquiries relating to the copyright in this document should be addressed to the Licensing Division, HMSO, St Clements House, 2-16 Colegate, Norwich NR3 1BQ. Fax 01603 723000 or e-mail: [email protected] MEASURES ADOPTED AT THE TWENTY-EIGHTH CONSULTATIVE MEETING HELD AT STOCKHOLM 6 - 17 JUNE 2005 The Measures1 adopted at the Twenty-eighth Antarctic Treaty Consultative Meeting are reproduced below from the Final Report of the Meeting. In accordance with Article IX, paragraph 4, of the Antarctic Treaty, the Measures adopted at Consultative Meetings become effective upon approval by all Contracting Parties whose representatives were entitled to participate in the meeting at which they were adopted (i.e. all the Consultative Parties). The full text of the Final Report of the Meeting, including the Decisions and Resolutions adopted at that Meeting, is available on the website of the Antarctic Treaty Secretariat at www.ats.aq. The approval procedures set out in Article 6 (1) of Annex V to the Protocol on Environmental Protection to the Antarctic Treaty2 apply to Measures 2, 3 and 4 (2005), and the approval procedures set out in Article 8(2) of Annex V to the Protocol apply to Measure 5 (2005).
    [Show full text]