Deep Sea Drilling Project Initial Reports Volume 35
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Cenozoic Changes in Pacific Absolute Plate Motion A
CENOZOIC CHANGES IN PACIFIC ABSOLUTE PLATE MOTION A THESIS SUBMITTED TO THE GRADUATE DIVISION OF THE UNIVERSITY OF HAWAI`I IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN GEOLOGY AND GEOPHYSICS DECEMBER 2003 By Nile Akel Kevis Sterling Thesis Committee: Paul Wessel, Chairperson Loren Kroenke Fred Duennebier We certify that we have read this thesis and that, in our opinion, it is satisfactory in scope and quality as a thesis for the degree of Master of Science in Geology and Geophysics. THESIS COMMITTEE Chairperson ii Abstract Using the polygonal finite rotation method (PFRM) in conjunction with the hotspot- ting technique, a model of Pacific absolute plate motion (APM) from 65 Ma to the present has been created. This model is based primarily on the Hawaiian-Emperor and Louisville hotspot trails but also incorporates the Cobb, Bowie, Kodiak, Foundation, Caroline, Mar- quesas and Pitcairn hotspot trails. Using this model, distinct changes in Pacific APM have been identified at 48, 27, 23, 18, 12 and 6 Ma. These changes are reflected as kinks in the linear trends of Pacific hotspot trails. The sense of motion and timing of a number of circum-Pacific tectonic events appear to be correlated with these changes in Pacific APM. With the model and discussion presented here it is suggested that Pacific hotpots are fixed with respect to one another and with respect to the mantle. If they are moving as some paleomagnetic results suggest, they must be moving coherently in response to large-scale mantle flow. iii List of Tables 4.1 Initial hotspot locations . -
Geodetic Determination of Relative Plate Motion and Crustal Deformation Across the Scotia-South America Plate Boundary in Eastern Tierra Del Fuego
Article Geochemistry 3 Volume 4, Number 9 Geophysics 19 September 2003 1070, doi:10.1029/2002GC000446 GeosystemsG G ISSN: 1525-2027 AN ELECTRONIC JOURNAL OF THE EARTH SCIENCES Published by AGU and the Geochemical Society Geodetic determination of relative plate motion and crustal deformation across the Scotia-South America plate boundary in eastern Tierra del Fuego R. Smalley, Jr. Center for Earthquake Research and Information, University of Memphis, 3876 Central Avenue, Ste. 1, Memphis, Tennessee 38152, USA ([email protected]) E. Kendrick and M. G. Bevis School of Ocean, Earth and Space Technology, University of Hawaii, 1680 East West Road, Honolulu, Hawaii 96822, USA ([email protected]; [email protected]) I. W. D. Dalziel and F. Taylor Institute of Geophysics, Jackson School of Geosciences, University of Texas at Austin, 4412 Spicewood Springs Road, Building 600, Austin, Texas 78759, USA ([email protected]; [email protected]) E. Laurı´a Instituto Geogra´fico Militar de Argentina, Cabildo 381, 1426 Buenos Aires, Argentina ([email protected]) R. Barriga Instituto Geogra´fico Militar de Chile, Nueva Santa Isabel 1640, Santiago, Chile ([email protected]) G. Casassa Centro de Estudios Cientı´ficos, Avda. Arturo Prat 514, Casilla 1469, Valdivia, Chile ([email protected]) E. Olivero and E. Piana Centro Austral de Investigaciones Cientı´ficas, Av. Malvinas Argentinas s/n, Caja de Correo 92, 9410 Ushuaia, Tierra del Fuego, Argentina ([email protected]; [email protected]) [1] Global Positioning System (GPS) measurements provide the first direct measurement of plate motion and crustal deformation across the Scotia-South America transform plate boundary in Tierra del Fuego. -
Open-File Report 2007-1047, Extended Abstracts
U.S. Geological Survey Open-File Report 2007-1047 Antarctica: A Keystone in a Changing World—Online Proceedings for the 10th International Symposium on Antarctic Earth Sciences Santa Barbara, California, U.S.A.—August 26 to September 1, 2007 Edited by Alan Cooper, Carol Raymond, and the 10th ISAES Editorial Team 2007 Extended Abstracts Extended Abstract 001 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea001.pdf Ross Aged Ductile Shearing in the Granitic Rocks of the Wilson Terrane, Deep Freeze Range area, north Victoria Land (Antarctica) by Federico Rossetti, Gianluca Vignaroli, Fabrizio Balsamo, and Thomas Theye Extended Abstract 002 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea002.pdf Postcollisional Magmatism of the Ross Orogeny (Victoria Land, Antarctica): a Granite- Lamprophyre Genetic Link S. Rocchi, G. Di Vincenzo, C. Ghezzo, and I. Nardini Extended Abstract 003 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea003.pdf Age of Boron- and Phosphorus-Rich Paragneisses and Associated Orthogneisses, Larsemann Hills: New Constraints from SHRIMP U-Pb Zircon Geochronology by C. J. Carson, E.S. Grew, S.D. Boger, C.M. Fanning and A.G. Christy Extended Abstract 004 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea004.pdf Terrane Correlation between Antarctica, Mozambique and Sri Lanka: Comparisons of Geochronology, Lithology, Structure And Metamorphism G.H. Grantham, P.H. Macey, B.A. Ingram, M.P. Roberts, R.A. Armstrong, T. Hokada, K. by Shiraishi, A. Bisnath, and V. Manhica Extended Abstract 005 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea005.pdf New Approaches and Progress in the Use of Polar Marine Diatoms in Reconstructing Sea Ice Distribution by A. -
Chapter 4 Tectonic Reconstructions of the Southernmost Andes and the Scotia Sea During the Opening of the Drake Passage
123 Chapter 4 Tectonic reconstructions of the Southernmost Andes and the Scotia Sea during the opening of the Drake Passage Graeme Eagles Alfred Wegener Institute, Helmholtz Centre for Marine and Polar Research, Bre- merhaven, Germany e-mail: [email protected] Abstract Study of the tectonic development of the Scotia Sea region started with basic lithological and structural studies of outcrop geology in Tierra del Fuego and the Antarctic Peninsula. To 19th and early 20th cen- tury geologists, the results of these studies suggested the presence of a submerged orocline running around the margins of the Scotia Sea. Subse- quent increases in detailed knowledge about the fragmentary outcrop ge- ology from islands distributed around the margins of the Scotia Sea, and later their interpretation in light of the plate tectonic paradigm, led to large modifications in the hypothesis such that by the present day the concept of oroclinal bending in the region persists only in vestigial form. Of the early comparative lithostratigraphic work in the region, only the likenesses be- tween Jurassic—Cretaceous basin floor and fill sequences in South Geor- gia and Tierra del Fuego are regarded as strong enough to be useful in plate kinematic reconstruction by permitting the interpretation of those re- gions’ contiguity in mid-Mesozoic times. Marine and satellite geophysical data sets reveal features of the remaining, submerged, 98% of the Scotia 124 Sea region between the outcrops. These data enable a more detailed and quantitative approach to the region’s plate kinematics. In contrast to long- used interpretations of the outcrop geology, these data do not prescribe the proximity of South Georgia to Tierra del Fuego in any past period. -
B. Antarctic Geologic Reports and Maps
I Ti). W LU. I- LU GLACIER SURFACE 500 7 - w E I Z .\c&A G /GLACIER 14/Lso,v 100 BOTTOM - SEA LEVEL --- GL.. -I ] —100 rs rA 5) -- 10 KM 1 B. Figure 1. Radio-echo sounding profiles extending (A) southward from McMurdo Sound through the Wilson Piedmont and Victoria Lower Glaciers to lower Victoria Valley, and (B) northeastward from lower Wright Valley through Wright Lower and Wilson Piedmont Glaciers to McMurdo Sound. Dashed lines representing snouts of valley glaciers are projections from maps or from other radio-echo data. Some small irregularities in glacier surfaces are caused by errors in pressure record of flight recorder. Figure 2. Radio-echo sounding profile westward from McMurdo Sound through lower Ferrar and upper Taylor Glaciers to 155°E. longitude, on Victoria Land plateau. EAST WEST ICE SHEET 145 ibco 1 500 200 SEA LEVEL--, -400 HIS SEEM " -200 KM ncrth—south faults bounding the eastern side of the Antarctic geologic reports and maps mountains may be indicated by steep breaks in slope occurring in the bottom trace of the profiles transect- CAMPBELL CRADDOCK in the Wilson Piedmont area (figs. 1A and 1B). Department of Geology and Geophysics Work described in this paper was undertaken at the University of Wisconsin, Madison Scott Polar Research Institute, Cambridge, England. Work has continued this year on bringing to publi- References cation the results of eight seasons of geologic study in Ca kin, P. E. In press. Glacial geology of the Victoria Valley parts of West Antarctica. Recent effort has focused on system, southern Victoria Land, Antarctica. -
Earth's Tectonic Plates
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Teaching TransparencyTeaching Master49 Transparency Tectonic Plates Earth’s MASTER 49 5.4 North American 1.8 Eurasian Plate Juan Plate 2.3 Divergent 3.7 de Fuca 5.4 boundary Plate Caribbean Philippine Convergent Plate 2.3 Arabian Plate boundary Cocos Plate 9.2 Plate 2.5 Pacific Plate Ridge axis 10.0 3.0 2.0 Transform African Plate 2.0 17.2 6.0 Earth theEnvironment, andtheUniverse Science:Geology, 10.5 boundary Nazca South American 6.2 Plate Plate Subduction zone TEACHING TRANSPARENCY Indian-Australian Plate 7.1 11.1 16.8 1.7 Zones of extension 4.1 within continents 10.3 6.0 1.3 7.3 3.7 3.3 Uncertain plate 7.7 7.5 7.2 boundary Antarctic Plate 5.0 Rate of movement 5.7 (cm/y) Use withChapter17 Section 17.3 97 Name Class Date WORKSHEET 49 TEACHING TRANSPARENCY Use with Chapter 17 Earth’s Tectonic Plates Section 17.3 1. In what direction is the Pacific Plate moving? 2. Are the Pacific Plate and the Antarctic Plate moving toward each other, away from each other, or past each other? Explain your answer. 3. What type of boundary separates the South American Plate from the Nazca Plate? Explain your answer. 4. Describe the relative motion between the North American Plate and the Pacific Plate. 5. Between which plates is the relative motion the fastest? 6. Would you predict that, over time, the distance between New York and Miami will increase, decrease, or stay the same? Explain your answer. -
Thurston Island
RESEARCH ARTICLE Thurston Island (West Antarctica) Between Gondwana 10.1029/2018TC005150 Subduction and Continental Separation: A Multistage Key Points: • First apatite fission track and apatite Evolution Revealed by Apatite Thermochronology ‐ ‐ (U Th Sm)/He data of Thurston Maximilian Zundel1 , Cornelia Spiegel1, André Mehling1, Frank Lisker1 , Island constrain thermal evolution 2 3 3 since the Late Paleozoic Claus‐Dieter Hillenbrand , Patrick Monien , and Andreas Klügel • Basin development occurred on 1 2 Thurston Island during the Jurassic Department of Geosciences, Geodynamics of Polar Regions, University of Bremen, Bremen, Germany, British Antarctic and Early Cretaceous Survey, Cambridge, UK, 3Department of Geosciences, Petrology of the Ocean Crust, University of Bremen, Bremen, • ‐ Early to mid Cretaceous Germany convergence on Thurston Island was replaced at ~95 Ma by extension and continental breakup Abstract The first low‐temperature thermochronological data from Thurston Island, West Antarctica, ‐ fi Supporting Information: provide insights into the poorly constrained thermotectonic evolution of the paleo Paci c margin of • Supporting Information S1 Gondwana since the Late Paleozoic. Here we present the first apatite fission track and apatite (U‐Th‐Sm)/He data from Carboniferous to mid‐Cretaceous (meta‐) igneous rocks from the Thurston Island area. Thermal history modeling of apatite fission track dates of 145–92 Ma and apatite (U‐Th‐Sm)/He dates of 112–71 Correspondence to: Ma, in combination with kinematic indicators, geological -
West Antarctica: Tectonics and Paleogeography
Chapter 2 West Antarctica: Tectonics and Paleogeography The origin of West Antarctica (WANT) can be traced back to the Terra Australis orogenesis that began between 520 Ma and 510 Ma—shortly after the terminal suturing of Gondwana (Boger 2011). The onset of this event was responsible for the termination of passive margin sedimentation along much of the Pacific margin of Gondwana and marks the beginning of widespread and broadly coeval deforma- tion and arc-type plutonism. It also began a long-lived process of accretion that added much of the crust that defines eastern Australia, West Antarctica (domain 5 of Boger 2011, Fig. 2.1), and western South America (Cawood 2005, 2009). Post-Gondwana accretionary growth—the Terra Australis and Gondwanide Orogenies—The suturing of the West Gondwana and Australo–Antarctic plates along the Kuunga Orogen brought to an end the long-lived process of convergence between the pre-collision components of Gondwana. The result was a reconfigura- tion of the early to middle Cambrian plate system and the consequent transfer of ocean floor consumption from between the pre-Gondwana cratons to the outboard Pacific margin of newly formed Gondwana supercontinent (Cawood2005 ). This led to the establishment of the accretionary Terra Austrais Orogen (Cawood 2005), a general name given to the orogenic belt that stretched continuously from north- ern South America to northern Australia and which began in the early to middle Cambrian and lasted until the late Carboniferous. In Antarctica Terra Australis (Ross) orogenesis also deformed and variably metamorphosed the pre-Gondwana passive margin (Fig. 2.2). The Gondwana supercontinent underwent a sequential fragmentation over approximately 165 Ma. -
Paper Is Divided Into Two Parts
Earth-Science Reviews 140 (2015) 72–107 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Geologic and kinematic constraints on Late Cretaceous to mid Eocene plate boundaries in the southwest Pacific Kara J. Matthews a,⁎, Simon E. Williams a, Joanne M. Whittaker b,R.DietmarMüllera, Maria Seton a, Geoffrey L. Clarke a a EarthByte Group, School of Geosciences, The University of Sydney, NSW 2006, Australia b Institute for Marine and Antarctic Studies, University of Tasmania, TAS 7001, Australia article info abstract Article history: Starkly contrasting tectonic reconstructions have been proposed for the Late Cretaceous to mid Eocene (~85– Received 25 November 2013 45 Ma) evolution of the southwest Pacific, reflecting sparse and ambiguous data. Furthermore, uncertainty in Accepted 30 October 2014 the timing of and motion at plate boundaries in the region has led to controversy around how to implement a Available online 7 November 2014 robust southwest Pacific plate circuit. It is agreed that the southwest Pacific comprised three spreading ridges during this time: in the Southeast Indian Ocean, Tasman Sea and Amundsen Sea. However, one and possibly Keywords: two other plate boundaries also accommodated relative plate motions: in the West Antarctic Rift System Southwest Pacific fi Lord Howe Rise (WARS) and between the Lord Howe Rise (LHR) and Paci c. Relevant geologic and kinematic data from the South Loyalty Basin region are reviewed to better constrain its plate motion history during this period, and determine the time- Late Cretaceous dependent evolution of the southwest Pacific regional plate circuit. A model of (1) west-dipping subduction Subduction and basin opening to the east of the LHR from 85–55 Ma, and (2) initiation of northeast-dipping subduction Plate circuit and basin closure east of New Caledonia at ~55 Ma is supported. -
Presentation on Pacific Plate and Associated Boundaries
PACIFIC PLATE AND ASSOCIATED BOUNDARIES The Pacific Plate • Pacific Plate is the largest plate and an oceanic plate. • It shares its boundaries with numerous plates namely; North American Plate.(Convergent and transform fault) Philippine Plate.(Convergent) Juan de Fuca Plate.(Convergent) Indo – Australian Plate.(Convergent, Transform Fault) Cocos Plate.(Divergent) Nazca Plate.(Divergent) Antarctic Plate.(Divergent,Transform Fault) Types of Plate Boundaries • Convergent Boundary: Subduction zones where two plates converges. Eg; Aleutian Islands(Alaska) • Divergent Boundary: Spreading centres where two plates move away from each other. Eg; East Pacific Rise (MOR, Pacific Ocean). • Transform Faults: Boundary where two plates slide past each other. For Eg. ; San Andreas Fault. BOUNDARY WITH ANTARCTIC PLATE DIVERGENT BOUNDARY • Pacific – Antarctic Ridge TRANSFORM FAULT • Louisville Seamount Chain Pacific – Antarctic Ridge Pacific – Antarctic Ridge(PAR) is located on the seafloor of the South Pacific Ocean. It is driven by the interaction of a mid oceanic ridge and deep mantle plumes located in the eastern portion of East Pacific Ridge. Louisville Seamount Chain It is the longest line of seamount chain in the Pacific Ocean of about 4,300 km, formed along the transform boundary in the western side between Pacific plate and Antarctic plate. It was formed from the Pacific Plate sliding over a long – lived centre of upwelling magma called the Louisville hotspot. BOUNDARY WITH PHILIPPINE PLATE CONVERGENT BOUNDARY • Izu – Ogasawara Trench • Mariana Trench Izu – Ogasawara Trench It is an oceanic trench in the western Pacific Ocean. It stretches from Japan to northern most section of Mariana Trench. Here, the Pacific Plate is being subducted beneath the Philippine Sea Plate. -
We Thank the Reviewers for Their Helpful Feedback, Which Has Improved Our Manuscript. in the Interactive Discussion, We Have Replied to Each Reviewer Directly
Dear Dr. Stroeven (editor), We thank the reviewers for their helpful feedback, which has improved our manuscript. In the Interactive Discussion, we have replied to each Reviewer directly. Below are copies of the Reviewers' comments and our responses as well as the revised manuscript with changes tracked. We would also like to bring to your attention the fact that we have made some changes to the manuscript regarding issues that were not raised by the Review- ers. These changes are described below. In the last paragraph of Section 5.3, we have changed the sentence which read \Circulation of drilling fluid in the RB-1 borehole hydrofractured the basal ice...". The new sentence reads \An unexplained hydrofracture of the basal ice of the RB-1 borehole...". After our initial manuscript submission, we realized that the present-day ground- ing line in our ice-sheet simulation was located upstream of Robin Subglacial Basin in the Weddell Sea sector of the WAIS (compare to Fig. 1). This misfit affects the plots in Fig. 2e-s because, at sites upstream of this area, thinning during interglacial periods is underestimated and thickening during glacial pe- riods is overestimated. To address this, we have taken the following actions. (i) We have added a figure (Fig. 3 in the revised manuscript) showing the misfit between the modeled and the observed present-day ice sheet. This figure shows that the model does reasonably well in most areas, but very poorly in the region of Robin Subglacial Basin. (ii) We added a paragraph to the end of Section 3 explaining this misfit and its consequences. -
A Revised Geochronology of Thurston Island, West Antarctica and Correlations Along the Proto
1 A revised geochronology of Thurston Island, West Antarctica and correlations along the proto- 2 Pacific margin of Gondwana 3 4 5 6 T.R. Riley1, M.J. Flowerdew1,2, R.J. Pankhurst3, P.T. Leat1,4, I.L. Millar3, C.M. Fanning5 & M.J. 7 Whitehouse6 8 9 1British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK 10 2CASP, 181A Huntingdon Road, Cambridge, CB3 0DH, UK 11 3British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK 12 4Department of Geology, University of Leicester, Leicester, LE1 7RH, UK 13 5Research School of Earth Sciences, The Australian National University, Canberra ACT 0200, Australia 14 6Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden 15 16 17 18 19 20 21 22 23 24 *Author for correspondence 25 e-mail: [email protected] 26 Tel. 44 (0) 1223 221423 1 27 Abstract 28 The continental margin of Gondwana preserves a record of long-lived magmatism from the Andean 29 Cordillera to Australia. The crustal blocks of West Antarctica form part of this margin, with 30 Palaeozoic – Mesozoic magmatism particularly well preserved in the Antarctic Peninsula and Marie 31 Byrd Land. Magmatic events on the intervening Thurston Island crustal block are poorly defined, 32 which has hindered accurate correlations along the margin. Six samples are dated here using U-Pb 33 geochronology and cover the geological history on Thurston Island. The basement gneisses from 34 Morgan Inlet have a protolith age of 349 ± 2 Ma and correlate closely with the Devonian – 35 Carboniferous magmatism of Marie Byrd Land and New Zealand.