DOCSLIB.ORG

Subsiding Sundaland Anne-Clarisse Sarr, Laurent Husson, Pierre Sepulchre, Anne-Morwenn Pastier, Kevin Pedoja, Mary Elliot, C

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Subsiding Sundaland Anne-Clarisse Sarr, Laurent Husson, Pierre Sepulchre, Anne-Morwenn Pastier, Kevin Pedoja, Mary Elliot, C Subsiding Sundaland Anne-Clarisse Sarr, Laurent Husson, Pierre Sepulchre, Anne-Morwenn Pastier, Kevin Pedoja, Mary Elliot, C. Arias-Ruiz, T. Solihuddin, S. Aribowo, Susilohadi Susilohadi To cite this version: Anne-Clarisse Sarr, Laurent Husson, Pierre Sepulchre, Anne-Morwenn Pastier, Kevin Pedoja, et al.. Subsiding Sundaland. Geology, Geological Society of America, 2019, 47 (2), pp.119-122. 10.1130/G45629.1. hal-02440378 HAL Id: hal-02440378 https://hal.archives-ouvertes.fr/hal-02440378 Submitted on 31 Mar 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Subsiding Sundaland Anta-Clarisse Sarr, Laurent Husson, Pierre Sepulchre, Anne-Morwenn Pastier, Kevin Pedoja, Mary Elliot, Camillo Arias Ruiz, Tubagus Solihuddin, Sonny Aribowo, Susilohadi Susilohadi To cite this version: Anta-Clarisse Sarr, Laurent Husson, Pierre Sepulchre, Anne-Morwenn Pastier, Kevin Pedoja, et al.. Subsiding Sundaland. American Geophysical Union 2018, Dec 2018, Washington, United States. pp.T31D-0338, 10.1130/G45629.1. insu-01928193 HAL Id: insu-01928193 https://hal-insu.archives-ouvertes.fr/insu-01928193 Submitted on 17 Aug 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Subsiding Sundaland A.-C. Sarr1,2, L. Husson1, P. Sepulchre2, A-M. Pastier1,3,4, K. Pedoja5, M. Elliot4, C. Arias-Ruiz4, T. Solihuddin6, S. Aribowo7, and Susilohadi8 1ISTerre, Université Grenoble Alpes, CNRS, 38058 Grenoble, France 2Laboratoire des Sciences du Climat et de l’Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris Saclay, France 3Géosciences Rennes, Université Rennes-1, 35042 Rennes Cedex, France 4Laboratoire de Planétologie et Géodynamique, Université Nantes, CNRS, 44300 Nantes, France 5Laboratoire de Morphodynamique Continentale et Côtière Caen, Université Caen, CNRS, 14000 Caen, France 6Marine Research Center, Ministry of Marine Affairs and Fisheries, Jakarta, Indonesia 7Indonesian Institute of Sciences (LIPI), Research center for Geotechnology, Bandung, Indonesia 8Marine Geological Institute, Marine Geological Research and Development Centre, Bandung, Indonesia ABSTRACT 10°N Sundaland is the currently partially drowned continental land- A Modern reef Earthquakes mass that encompasses Borneo, Sumatra, Java, and the Malay Penin- Malaysia sula. It has episodically been reclaimed by the sea during successive Sunda Shelf Pacific Ocean Quaternary glaciations, and is commonly thought to be vertically Sumatra stable. Combining geomorphological observations with numerical 0 Borneo simulations of coral reef growth and shallow seismic stratigraphy, Papua we show that the Sunda shelf is subsiding, and that the intermittent Wallacea regime of transgressions only prevailed over the past 400,000 yr. Prior Java to that time, Sundaland was permanently exposed. We relate these 10°S Sahul shelf drowning events to transient dynamic topography in the Indo-Austra- Belitung Java Trench lian subduction zone. Because the Sunda shelf is very shallow, these Indian Ocean 1,000 km new data provide important insights into Pleistocene paleogeography, 40 km Australia 10°N with implications on the interactions between the solid Earth and B Alluvial plains Mangroves climate, oceanography, and dispersal of species, including hominids. Pleistocene coral reefs Vertical land motion LARGE-SCALE DEFORMATION PATTERN IN SOUTHEAST Sunda S. ASIA 0 Cenozoic Sundaland (the area that encompasses Borneo, Sumatra, Java, the Malay Peninsula, and the Java Sea) paleogeographies are available up to the Early Pliocene (e.g., Hall, 2009) but its more recent paleoge- ography remains largely unknown. The core of Sundaland is nearly tec- 10°S Banda arc Sahul S. tonically quiescent (Fig. 1A), and fooding of its shallow areas (<100 m depth) is regarded as only contingent on eustatic sea-level changes (Voris, Bathymetry (m) 2001); the Sunda shelf being fully exposed during Quaternary glacial -120 0 1,000 km periods, and partly drowned during interglacials, as it is today. However, 100°E 110°E120°E 130°E 140°E the shelf’s location above the quickly evolving Indo-Australian subduc- Figure 1. Quaternary coastal morphotectonics in Southeast Asia. A: tion zone, where mantle convection effciently modifes the physiography Earthquakes (M >4 ; U.S. Geological Survey catalog, 1960–2010; https:// (Zahirovic et al., 2016), challenges the default assumption of stability earthquake.usgs.gov/earthquakes/search/) outline the low-seismic- for the shelf. That assumption, which has implications for the Neogene activity area within Sundaland. Inset: Location of dated mid-Holocene reef on Belitung island (red circles). Modern coral reefs are ubiquitous biogeography of Southeast Asia (e.g., Richardson et al., 2013), has not (A) whereas Pleistocene reefs (B) are only found in Wallacea. B: Alluvial yet been properly tested. plains and mangroves prevail in the Sunda and Sahul shelves, and Wallacea (Eastern Indonesia, mostly) actively deforms in response Pleistocene reefs in Wallacea. Vertical land motion (Table DR1 [see to the collision with Australia (e.g., Pownall et al., 2016). Flights of footnote 1]) reveal uplift in Wallacea and subsidence in Sunda and Sahul (white arrows; current study in red). Sundaland encompasses uplifted marine terraces are widespread and attest to an overall Pleisto- the Sunda shelf, Malay Peninsula, Borneo, Java, and Sumatra. Sahul cene uplift of Wallacea (e.g., Pedoja et al., 2018; Table DR1 in the GSA is the shallow north Australian platform, while the deeper Wallacea Data Repository1). Conversely, wide alluvial plains stretch over most lies between Sahul and Sundaland. 1 GSA Data Repository item 2019048, Tables DR1 and DR2 and Figures DR1–DR4, including raw seismic profle and information on the model used for this study, is available online at http://www.geosociety.org/datarepository/2019/, or on request from [email protected]. 1 coastal regions of Sahul and Sunda, and extend hundreds of kilometers A (1) 6.2 - 6.7 kyr B.P Regressive sequence (Methods) inland (Fig. 1B). Onshore marine sediments, and reefs older than Holo- (2) 6.5 - 7.3 kyr B.P x Basement Sand Reef cene age, are never exposed even though reefs bloomed in the region Holocene microatolls Modern microatolls during the late Cenozoic (Wilson and Rosen, 2008) and currently thrive Modern corals 1m Modern SL in Southeast Asia, including Sunda and Sahul (Fig. 1A). Such contrast- 25 m ing morphologies between Wallacea and surrounding shelves are the x ? x x consequence of different uplift and subsidence histories (Evans et al., x x x x ? x x x x x x x xxx x x x 1936). Late Quaternary subsidence rates for the Sunda shelf are only x x x x x –1 reported on the northern margin (0.13–0.27 mm yr ,Wong et al., 2003; 3,000 m ~1,200 m 0.25 mm yr–1, Hanebuth et al., 2011) or in the Singapore strait (0.06–0.10 mm yr–1, Bird et al., 2006) but are absent from the core of the shelf (Fig. B Modern reef width (km) 1B). Sahul subsides at 0.12–0.45 mm yr–1 (Table DR1) and, based on 0.0 ) 02 64 810 -1 0T its morphological similarity with Sunda (Fig. 1B), we hypothesize that 0T (km)(k m) 10 kmkm rather than being vertically stable, the Sunda shelf may be experiencing similar long-wavelength subsidence. While the shelf is currently drowned mm.yr 0.2 1T 1T 1 km at 30 m below sea level (bsl), the absence of marine sediments onshore 1T and the thin layer of alluvia that overlays laterites and substratum (Ben- 2T Avraham and Emery, 1973) attest to continental Cenozoic erosion and 0.4 2T2T 1 km recent inundation (Hall and Morley, 2004). 3T 0004 0 0002 0 0 Subsidence rate ( Here we use morphological indicators (coastal landforms such as 0 0 0 3T 4 1 km 2 modern and fossil reefs, mangroves, and alluvial plains; Fig. 1B) and 0.6 6000 shallow stratigraphy to capture the pattern of Pleistocene vertical land 0.0 1.0 2.0 Foundation Slope (%) motion in Southeast Asia. We focus on the Tin Belt islands, in the inner 14 Sunda shelf, and combine numerical modeling of reef growth with C C 100 - 0.3 mm.yr - 0.3 mm.yr- 0.2 mm.yr Emersion dating of mid-Holocene reefs to constrain subsidence rates in this region - 0.2 mm.yr -1 Submersion -1 -1 where almost no data exist, ultimately demonstrating the uniformity of 50 -1 subsidence in the Sunda shelf. 0 SUNDA SHELF SUBSIDENCE 0 mm/yr Karimata strait In order to quantify subsidence rates, we use sequences of coral reefs −50 (Belitung) that fngerprint sea-level oscillations, and ubiquitously stack in fights of sea level (m) Northern marine terraces in the intertropical zone (Pedoja et al., 2014). Those reef −100 0 mm.yr -1-1 shelf sequences are indirect sensors of a variety of parameters, including uplift 0 mm.yr 11 97 5 mis 11 mis 5e or subsidence rates that numerical models can invert for (Toomey et al., −150 2013). We develop an original probabilistic approach, based on a numeri- 0100200300400500600700800 cal model that reproduces the inferred architecture of coral reef sequences Time (ka) calibrated by feld measurements, to probe Quaternary subsidence rates D W E for the Sunda shelf (Husson et al., 2018; see the Data Repository).
Load more

Recommended publications
  • Regional Maritime Issues, Can the Indian Ocean Be Collaboratively Managed?
    Regional Maritime Issues, Can the Indian Ocean be Collaboratively Managed? First Admiral Anuar bin Mohamed Assistant Chief of Staff Human Resource, Royal Malaysian Navy Can the Indian Ocean be Collaboratively Managed? It covers an area of 68.556 million sq km, which includes amongst others, the Andaman The Hypothesis: Collaboration could not be Sea, Arabian Sea, Bay of Bengal, Flores Sea, fully achieved in IOR, as long as there is a great Great Australian Bight, Gulf of Aden, Gulf of power politics that enhance the geopolitical and Oman, Java Sea, Mozambique Channel, Persian geostrategic struggles in the region. Gulf, Red Sea, Savu Sea, Strait of Malacca and Timor Sea. This is viewed through the lens of neo-realism, where the structural defects would eventually By comparison, it consists of an area that is make efforts for collaboration/cooperation almost 7 times the size of the United States. impossible. Bordering this ocean and the states around it is the 66,526 km coastlines. In arguing this, we need to understand the features of the IOR iot determined factors that In a nutshell, it covers 30% of the global ocean would affect the argument. area home to 30% of the world’s population and 30% of the world’s coral reef cover. Background Geographically : Economically: This ocean hosts abundant of natural Indian Ocean Region (IOR) has unique resources of oil and gas fields, fish, shrimp, characteristics compared to other oceanic sand and gravel aggregates, placer deposits and regions. poly-metallic nodules. It is the third largest of the world's five oceans, It also provide various major sea routes after the Pacific and the Atlantic Ocean.
    [Show full text]
  • Submarine Morphology of the Sahul Shelf, Northwestern Australia
    TJEERD H. VAN ANDEL JOHN J. VEEVERS SUBMARINE MORPHOLOGY OF THE SAHUL SHELF, NORTHWESTERN AUSTRALIA Abstract: The Sahul Shelf, located between north- of which it probably is the submerged extension. western Australia and the Timor Trough, consists This requires uplift, weathering, and denudation of a central basin surrounded by broad, shallow of the shelf in middle and late Tertiary. Subse- rises. Superimposed on the regional relief is a quently, the shelf was deformed to form the basin system of banks, terraces, and channels. The flat and rises. This deformation caused the original tops of banks and terraces form parts of several drainage to become antecedent. Lower surfaces regional, subhorizontal surfaces. The steplike to- were formed during Pleistocene low sea-level pography closely resembles the system of late stands. Cenozoic erosional surfaces on the adjacent land area with the shelf edge. The Sahul Rise sepa- Introduction rates the Bonaparte Depression from the Timor The Sahul Shelf, off the northwest coast of Trough. The basin is connected with deep Australia, is a very wide continental shelf water by a long, narrow valley with a maximum which derives its interest primarily from its depth of 200 m, Malita Shelf Valley. position between the continental mass of The shelf edge is represented by a gradual Australia and the island arches and geosynclines change in slope, usually marked by a low cliff of Indonesia. An early study, based on con- at 110-130 m. A second shelf edge at approxi- ventional nautical charts, was made by Fair- mately 550 m, reported by Fairbridge (1953), bridge (1953).
    [Show full text]
  • Predominant Colonization of Malesian Mountains by Australian Tree Lineages
    Received: 28 February 2019 | Revised: 30 September 2019 | Accepted: 7 October 2019 DOI: 10.1111/jbi.13747 RESEARCH PAPER Predominant colonization of Malesian mountains by Australian tree lineages Fabian Brambach1 | Christoph Leuschner1 | Aiyen Tjoa2 | Heike Culmsee1,3 1Plant Ecology and Ecosystems Research, University of Goettingen, Abstract Goettingen, Germany Aim: Massive biota mixing due to plate-tectonic movement has shaped the bioge- 2 Agriculture Faculty, Tadulako University, ography of Malesia and during the colonization process, Asian plant lineages have Palu, Indonesia 3DBU Natural Heritage, German Federal presumably been more successful than their Australian counterparts. We aim to gain Foundation for the Environment, Osnabrück, a deeper understanding of this colonization asymmetry and its underlying mecha- Germany nisms by analysing how species richness and abundance of Asian versus Australian Correspondence tree lineages in three Malesian subregions change along environmental gradients. Fabian Brambach, Biodiversity, Macroecology and Biogeography, Faculty We hypothesize that differing environmental histories of Asia and Australia, and their of Forest Sciences and Forest Ecology, relation to habitats in Malesia, have been important factors driving assembly pat- University of Goettingen, Buesgenweg 1, 37077 Goettingen, Germany. terns of the Malesian flora. Email: [email protected] Location: Malesia, particularly Sundaland, the Philippines and Wallacea. Funding information Taxon: Seed plants (trees). Deutsche Forschungsgemeinschaft,
    [Show full text]
  • Indonesian Seas by Global Ocean Associates Prepared for Office of Naval Research – Code 322 PO
    An Atlas of Oceanic Internal Solitary Waves (February 2004) Indonesian Seas by Global Ocean Associates Prepared for Office of Naval Research – Code 322 PO Indonesian Seas • Bali Sea • Flores Sea • Molucca Sea • Banda Sea • Java Sea • Savu Sea • Cream Sea • Makassar Strait Overview The Indonesian Seas are the regional bodies of water in and around the Indonesian Archipelago. The seas extend between approximately 12o S to 3o N and 110o to 132oE (Figure 1). The region separates the Pacific and Indian Oceans. Figure 1. Bathymetry of the Indonesian Archipelago. [Smith and Sandwell, 1997] Observations Indonesian Archipelago is most extensive archipelago in the world with more than 15,000 islands. The shallow bathymetry and the strong tidal currents between the islands give rise to the generation of internal waves throughout the archipelago. As a result there are a very 453 An Atlas of Oceanic Internal Solitary Waves (February 2004) Indonesian Seas by Global Ocean Associates Prepared for Office of Naval Research – Code 322 PO large number of internal wave sources throughout the region. Since the Indonesian Seas boarder the equator, the stratification of the waters in this sea area does not change very much with season, and internal wave activity is expected to take place all year round. Table 2 shows the months of the year during which internal waves have been observed in the Bali, Molucca, Banda and Savu Seas Table 1 - Months when internal waves have been observed in the Bali Sea. (Numbers indicate unique dates in that month when waves have been noted) Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec 12111 11323 Months when Internal Waves have been observed in the Molucca Sea.
    [Show full text]
  • Structural and Stratigraphic Evolution of the Savu Basin, Indonesia
    Structural and stratigraphic evolution of the Savu Basin, Indonesia JAMES W. D. RIGG* & ROBERT HALL SE Asia Research Group, Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK *Corresponding author (e-mail: [email protected]) Abstract: The Savu Basin is located in the Sunda–Banda fore-arc at the position of change from oceanic subduction to continent–arc collision. It narrows eastward and is bounded to the west by the island of Sumba that obliquely crosses the fore-arc. New seismic data and published geological observations are used to interpret Australia–Sundaland convergence history. We suggest the basin is underlain by continental crust and was close to sea level in the Early Miocene. Normal faulting in the Middle Miocene and rapid subsidence to several kilometres was driven by subduction rollback. Arc-derived volcaniclastic turbidites were transported ESE, parallel to the Sumba Ridge, and then NE. The ridge was elevated as the Australian continental margin arrived at the Banda Trench, causing debris flows and turbidites to flow northwards into the basin which is little deformed except for tilting and slumping. South of the ridge fore-arc sediments and Australian sedimentary cover were incorporated in a large accretionary complex formed as continental crust was thrust beneath the fore-arc. This is bounded to the north by the Savu and Roti Thrusts and to the south by a trough connecting the Java Trench and Timor Trough which formed by south-directed thrust- ing and loading. The Savu Basin is situated in the fore-arc of the Roti and the Savu Basin connects the Timor Trough Sunda–Banda Arc (Fig.
    [Show full text]
  • Observed Estimates of Convergence in the Savu Sea, Indonesia James T
    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. C1, 3001, doi:10.1029/2002JC001507, 2003 Observed estimates of convergence in the Savu Sea, Indonesia James T. Potemra,1 Janet Sprintall,2 Susan L. Hautala,3 and Wahyu Pandoe4,5 Received 11 June 2002; revised 25 September 2002; accepted 10 October 2002; published 2 January 2003. [1] The Indonesian seas are known to be a region where various Pacific and Indian Ocean water masses converge and are transformed into uniquely characterized Indonesian Sea Water (ISW). The volume of Pacific surface waters that are stored in the Indonesian seas and the timescales for this volume to change are important factors in the formulation of ISW that ultimately enters the Indian Ocean as the Indonesian throughflow (ITF). In this study, data from a recent deployment of pressure gauges surrounding the Savu Sea are used to estimate volume, heat, and freshwater convergence within approximately the upper 100 m. A pair of gauges on the northeastern side (North Ombai and South Ombai) is used to estimate inflow from the Banda Sea through the Ombai Strait, and two pairs (Sumbawa/North Sumba and South Sumba/Roti) are used to estimate outflow to the Indian Ocean via the Sumba and Savu/Dao Straits. The data are used in conjunction with numerical model results to show that at times, for example, November and December of 1996, there can be up to a 10 Sv imbalance between the inflow and the outflow transport. Most of the variability in estimated convergence occurs intraseasonally and seems to be controlled by the flow through the Sumba Strait on the eastern side of the sea.
    [Show full text]
  • Surveys of the Sea Snakes and Sea Turtles on Reefs of the Sahul Shelf
    Surveys of the Sea Snakes and Sea Turtles on Reefs of the Sahul Shelf Monitoring Program for the Montara Well Release Timor Sea MONITORING STUDY S6 SEA SNAKES / TURTLES Dr Michael L Guinea School of Environment Faculty of Engineering, Health, Science and the Environment Charles Darwin University Darwin 0909 Northern Territory Draft Final Report 2012-2013 Acknowledgements: Two survey by teams of ten and eleven people respectively housed on one boat and operating out of three tenders for most of the daylight hours for 20 days and covering over 2500 km of ocean can only succeed with enthusiastic members, competent and obliging crew and good organisation. I am indebted to my team members whose names appear in the personnel list. I thank Drs Arne Rasmussen and Kate Sanders who gave their time and shared their knowledge and experiences. I thank the staff at Pearl Sea Coastal Cruises for their organisation and forethought. In particular I thank Alice Ralston who kept us on track and informed. The captains Ben and Jeff and Engineer Josh and the coxswains Riley, Cam, Blade and Brad; the Chef Stephen and hostesses Sunny and Ellen made the trips productive, safe and enjoyable. I thank the Department of Environment and Conservation WA for scientific permits to enter the reserves of Sandy Islet, Scott Reef and Browse Island. I am grateful to the staff at DSEWPaC, for facilitating and providing the permits to survey sea snakes and marine turtles at Ashmore Reef and Cartier Island. Activities were conducted under Animal Ethics Approval A11028 from Charles Darwin University. Olive Seasnake, Aipysurus laevis, on Seringapatam Reef.
    [Show full text]
  • The Sunda Shelf the Continent, People Were Forced to Flee in All Discover Island Sanctuaries from the Directions
    Seen&HeArd lying over the Anambas Islands is a lovely sight. Island after island dots the sea with azure blue reefs blending into rainforest mountain peaks. Only 24 of these 238 islands Fare inhabited – a hidden world amidst the bustling South China Sea. I contemplate the spectacular scenery from the window flying overhead and realise that only the mountain tops are peaking up through the waters edge and recall reading about the drowned continent of Southeast Asia called Sundaland. This ancient land of Asia became the South China Sea about 8,000 years ago when the ocean water rose at the end of the last ice age. Once fertile valleys and To The Heights Of lowlands now lie submerged, forests turned into reefs, lagoons and a rolling continental shelf. During these years, as the ocean claimed The Sunda Shelf the continent, people were forced to flee in all Discover island sanctuaries from the directions. Those who lived near mountains would lost continent of Sundaland. have moved upwards, but those living in the valleys By Abigail Alling, President PCRF and far from the mountains were flooded. Thus, these people gathered themselves and became sea nomads, adrift in search of higher land. Many colourful, bustling city with ample supplies and think that these “sea-people” from this ancient gentle, friendly people. Just around the corner, civilization spread north to the Asian continent, on the waters edge in a sheltered bay, is a hotel south to Australia, west to Africa and the Middle located at Tanjung Tebu. There you will find excellent East, and east to Polynesia.
    [Show full text]
  • Indonesia's Transformation and the Stability of Southeast Asia
    INDONESIA’S TRANSFORMATION and the Stability of Southeast Asia Angel Rabasa • Peter Chalk Prepared for the United States Air Force Approved for public release; distribution unlimited ProjectR AIR FORCE The research reported here was sponsored by the United States Air Force under Contract F49642-01-C-0003. Further information may be obtained from the Strategic Planning Division, Directorate of Plans, Hq USAF. Library of Congress Cataloging-in-Publication Data Rabasa, Angel. Indonesia’s transformation and the stability of Southeast Asia / Angel Rabasa, Peter Chalk. p. cm. Includes bibliographical references. “MR-1344.” ISBN 0-8330-3006-X 1. National security—Indonesia. 2. Indonesia—Strategic aspects. 3. Indonesia— Politics and government—1998– 4. Asia, Southeastern—Strategic aspects. 5. National security—Asia, Southeastern. I. Chalk, Peter. II. Title. UA853.I5 R33 2001 959.804—dc21 2001031904 Cover Photograph: Moslem Indonesians shout “Allahu Akbar” (God is Great) as they demonstrate in front of the National Commission of Human Rights in Jakarta, 10 January 2000. Courtesy of AGENCE FRANCE-PRESSE (AFP) PHOTO/Dimas. RAND is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND® is a registered trademark. RAND’s publications do not necessarily reflect the opinions or policies of its research sponsors. Cover design by Maritta Tapanainen © Copyright 2001 RAND All rights reserved. No part of this book may be reproduced in any form by any electronic or mechanical means (including photocopying,
    [Show full text]
  • Geological Society, London, Special Publications
    Geological Society, London, Special Publications Australia−SE Asia collision: plate tectonics and crustal flow Robert Hall Geological Society, London, Special Publications 2011; v. 355; p. 75-109 doi: 10.1144/SP355.5 Email alerting click here to receive free e-mail alerts when new service articles cite this article Permission click here to seek permission to re-use all or part of request this article Subscribe click here to subscribe to Geological Society, London, Special Publications or the Lyell Collection Notes Downloaded by on August 5, 2011 © The Geological Society of London 2011 Australia–SE Asia collision: plate tectonics and crustal flow ROBERT HALL SE Asia Research Group, Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK (e-mail: [email protected]) Abstract: The Sundaland core of SE Asia is a heterogeneous assemblage of Tethyan sutures and Gondwana fragments. Its complex basement structure was one major influence on Cenozoic tec- tonics; the rifting history of the north Australian margin was another. Fragments that rifted from Australia in the Jurassic collided with Sundaland in the Cretaceous and terminated subduction. From 90 to 45 Ma Sundaland was largely surrounded by inactive margins with localized strike- slip deformation, extension and subduction. At 45 Ma Australia began to move north, and subduc- tion resumed beneath Sundaland. At 23 Ma the Sula Spur promontory collided with the Sundaland margin. From 15 Ma there was subduction hinge rollback into the Banda oceanic embayment, major extension, and later collision of the Banda volcanic arc with the southern margin of the embayment.
    [Show full text]
  • Metcalfe 2011 Gond Res Sundaland.Pdf
    Gondwana Research 19 (2011) 3–21 Contents lists available at ScienceDirect Gondwana Research journal homepage: www.elsevier.com/locate/gr Tectonic framework and Phanerozoic evolution of Sundaland Ian Metcalfe ⁎ Earth Sciences, Earth Studies Building C02, School of Environmental and Rural Science, University of New England, Armidale NSW 2351, Australia National Key Centre for Geochemical Evolution and Metallogeny of Continents (GEMOC), Department of Earth and Planetary Sciences, Macquarie University, NSW 2109, Australia article info abstract Article history: Sundaland comprises a heterogeneous collage of continental blocks derived from the India–Australian Received 4 December 2009 margin of eastern Gondwana and assembled by the closure of multiple Tethyan and back-arc ocean basins Received in revised form 23 February 2010 now represented by suture zones. The continental core of Sundaland comprises a western Sibumasu block Accepted 24 February 2010 and an eastern Indochina–East Malaya block with an island arc terrane, the Sukhothai Island Arc System, Available online 21 March 2010 comprising the Linchang, Sukhothai and Chanthaburi blocks sandwiched between. This island arc formed on the margin of Indochina–East Malaya, and then separated by back-arc spreading in the Permian. The Keywords: – Sundaland Jinghong, Nan Uttaradit and Sra Kaeo Sutures represent this closed back-arc basin. The Palaeo-Tethys is Tectonic framework represented to the west by the Changning–Menglian, Chiang Mai/Inthanon and Bentong–Raub Suture Zones. Phanerozoic evolution The West Sumatra block, and possibly the West Burma block, rifted and separated from Gondwana, along Palaeogeography with Indochina and East Malaya in the Devonian and were accreted to the Sundaland core in the Triassic.
    [Show full text]
  • Adec Preview Generated PDF File
    Rec. West. Aust. M"... Suppl. No. 44.1993 Part 1 Historical background, description of the physical environments of Ashmore Reef and eartier Island and notes on exploited species P.F. Berry* Abstract Ashrnore Reef (12°17'S, 123°02'E) and nearby Cartier Island (l2°32'S, 123°33'E) are located on tl.e north-western extremity of the Sahul Shelf. They are approximately 350 km off the Kimberley coast of Australia and 145 km from Roti, Indonesia. The morphology and physical environments of the two reef systems are briefly described as a background to faunal inventories presented in Parts 2-7 ofthis publication. Ashrnore Reef (approximately 26 km long and 14 km wide) is similar in general shape and morphology to other shelf-edge atolls off the north-western coast of Australia, but because of the larger breaks in the reef there is no impounding of water in the lagoon on outgoing tides as at the Rowley Shoals and to a lesser extent, Scott Reef. There are three vegetated islets on Ashmore Reef. Cartier Island, an unvegetated sand cay, is surrounded by an oval-shaped reef platform approximately 4.5 km long by 2.3 km wide. Mean sea surface temperatures range from approximately 24°C in July and August to 30°C between January and March. Spring and neap tidal ranges (semi-diurnal) are 4.7 m and 2.8 m respectively. Observations on species exploited in the traditional Indonesian fishery are recorded. These suggest that composition and abundance of exploited species at Ashmore Reef and Cartier Island reflect a higher level of fishing effort there than at Scott Reef and Rowley Shoals.
    [Show full text]