DOCSLIB.ORG

The Geomorphological and Geological Importance of Palaeosurfaces

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Geomorphological and Geological Importance of Palaeosurfaces Downloaded from http://sp.lyellcollection.org/ by guest on October 2, 2021 The geomorphological and geological importance of palaeosurfaces M. WIDDOWSON Department of Earth Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK This Special Publication is a collection of papers cations of ancient palaeosurfaces. The research which identifies, describes, and interprets the areas represented are geographically widespread occurrence of palaeosurfaces in the geological and include examples from Australia, Africa, South record. The concept of a palaeosurface is one America, India, and Europe. which is generally understood across the geo- morphological and geological sciences but, The importance of palaeosurfaces according to discipline and application, often differs in the emphasis and detail of its This Special Publication is timely for two main interpretation. In order to encompass the widest reasons. First, in recent years geologists, range of contributions and views upon the subject geophysicists, and geomorphologists have begun of palaeosurfaces, a broad remit was deliberately to look anew at landscape evolution because adopted during the preparation of this volume. it has become increasingly apparent that the characteristics of major landscape components, Background and objectives such as palaeosurfaces, can potentially provide important clues to fundamental questions regarding Many working groups within the geological and the nature of macro-scale (i.e. tectonic) processes, geomorphological sciences share a common link and the rate and timing of uplift and erosion. Such through the Geological Society, and it is hoped an approach is evident from many recent papers that this volume will further illustrate the potential which have sought to define both uplift and erosion of cross-disciplinary study. Geology and geo- in terms of the surface expression of crustal and morphology, though often approached by different mantle dynamics (e.g. McKenzie 1984; England & research schools, are both expressions of complex Houseman 1988; England & Molnar 1990; Cox Earth systems and as such can rarely be treated 1989; Watts & Cox 1989; Gilchrist & Summerfield independently. Since the investigation of palaeo- 1994; Brown et al. 1994b; Povey et al. 1994; Sttiwe surfaces requires an understanding of both et al. 1994; Burbank et al. 1996): Second, there has geomorphological and geological processes, their been common recognition of the benefit of a more study is clearly a theme which demands this type of unified treatment of both landscape evolution and cross-disciplinary approach. Therefore, the aim of sediment deposition systems. The development of this volume is to bring together expertise from a this latter approach has been greatly assisted by the variety of fields by researchers in both the advent of advanced computer modelling which has geological and geomorphological disciplines who allowed calculation of macro-scale erosion and have adopted such a combined approach to sedimentation budgets. As a consequence, the palaeosurface research. dynamics of landscape erosion, fluvial systems, and Contributions have been encouraged from the associated stratigraphical evolution of sedimentary fields of geomorphology, geology, geochemistry, basins, so long treated as independent research palynology and palaeoenvironmental studies. The themes within geomorphology and geology, are papers include studies of geomorphological now being considered in a more unifed approach evolution, reconstruction of palaeolandscapes, (e.g. Brown et al. 1990; Schlager 1993; Whiting lateritization and bauxitization, palaeo-karstifi- et al. 1994; Burgess & Allen 1996; Widdowson & cation, sequence stratigraphy, geochemistry of rock Cox 1996). Clearly, future dialogue and exchange alteration, the preservation of palaeosurface between the different working groups will provide elements in both glaciated and sub-tropical regions, a basis for fashioning an increasingly holistic and the use of palaeosurfaces as an indicator of treatment of the processes acting both upon and regional-scale neotectonic deformation. More- beneath the Earth's surface. However, there over, many incorporate discussion regarding remains great potential for exploring the interaction fundamental aspects of evolution, interpretation, between tectonics and long-term landscape reconstruction, and palaeoenvironmental impli- evolution; the great antiquity and lateral extent of From Widdowson, M. (ed.), 1997, Palaeosurfaces: Recognition, Reconstruction and Palaeoenvironmental Interpretation, Geological Society Special Publication No. 120, pp. 1-12. Downloaded from http://sp.lyellcollection.org/ by guest on October 2, 2021 2 M. WIDDOWSON many palaeosurfaces can provide a suitable spatial horizon of demonstrable antiquity. Within a and temporal framework for evaluating the link geological context, the importance of identifying between tectonic processes and their effect upon ancient surfaces in the rock record has long been the development of geomorphological components recognized since they are often employed to divide and associated erosional-depositional systems. stratigraphies (or other lithological or pedological Such a treatment is desirable since it has the units) into genetically and temporally related potential to reveal information about fundamental packages. Such geological surfaces often result mechanisms acting deep within the Earth, and to from fundamental changes or hiatuses in deposition make a valuable contribution to our understanding processes influenced by factors including tectonism of how the landscapes, and the processes acting or environmental change. Alternatively, they may upon them, function over long time scales. be related both directly or indirectly to changes in the nature or rate of geomorphological processes which have the potential to alter or interrupt the established pattern of stratigraphical development. What is a palaeosurface? Some ideas Historically there has existed an often subtle, but It is evident from the papers submitted for this nevertheless fundamental difference in the way in volume that the concept of palaeosurfaces which the term has been employed by geologists encompasses a wide range of geological and and geomorphologists. It can be held that this geomorphological phenomena. This makes difficult difference of research perspective arises from the any attempt to provide a palaeosurface definition manner in which the two disciplines view the which readily encompasses all areas of study. One ancient record. Within the geological sciences the fundamental distinction which can be made, term appears to have attained a rather wide however, is the difference between exogenic and interpretation because geologists tend to view Earth endogenic surfaces: Exogenic processes act upon surface systems in a depositional or constructive the Earth's exposed surface and include the (endogenic) framework and therefore consider a action of ice, wind, water, and biota which result whole variety of surface types, whether they be in denudation and a net reduction in elevation. formed by erosion or other forms of depositional Clearly, many identified palaeosurfaces have gaps (i.e. unconformities), as an integral and evolved largely as the result the exogenic fundamental part of the stratigraphical record. geomorphological agents of weathering and Consequently, the term has been employed to erosion. However, there exist other types of describe surfaces preserved in both sub-aerial surfaces which are demonstrably of an endogenic and sub-aqueous sequences and it therefore origin. These include constructional processes, encompasses a variety of features originating from often of geological origin, such as those resulting a range of erosional and depositional processes from crustal uplift (i.e. orogenic and epeirogenic), (e.g. unconformity surfaces arising from the and igneous activity (e.g. surface volcanic erosion and removal of strata, breaks in structures and surface doming by magmatic sedimentation, or other fundamental changes in injection). Since endogenic examples are typically deposition or deposition rates, for instance). constructional in nature they tend to be associated However, it is evident geomorphologists often with an increase in elevation of relief. Good consider the ancient record in an essentially examples include those resulting from epeiro- destructive (exogenic) framework, since their genesis (a broad uplift of the crust resulting from work is primarily concerned with the processes thermal or dynamic processes within the Earth), of weathering and erosion; these being the two examples arising from the structural effects of main factors which determine the evolution of faulting and folding in regions of tectonic landforms. Geomorphologically speaking, the convergence, or those of a volcanogenic derivation palaeosurface concept involves features, typically such as lava fields. Nevertheless, it is important to within a palaeolandscape framework, which are realize that in the ancient record pure endogenic characteristically erosional and usually, though not surfaces may be uncommon, for unless these exclusively, sub-aerial in origin. Consequently, the endogenic surfaces rapidly become covered and term is commonly accepted as being something effectively fossilized by younger materials an much more specific and complex than the rather increasingly important exogenic contribution to generic 'ancient surface' definition suggested surface morphology will
Load more

Recommended publications
  • The Geology of England – Critical Examples of Earth History – an Overview
    The Geology of England – critical examples of Earth history – an overview Mark A. Woods*, Jonathan R. Lee British Geological Survey, Environmental Science Centre, Keyworth, Nottingham, NG12 5GG *Corresponding Author: Mark A. Woods, email: [email protected] Abstract Over the past one billion years, England has experienced a remarkable geological journey. At times it has formed part of ancient volcanic island arcs, mountain ranges and arid deserts; lain beneath deep oceans, shallow tropical seas, extensive coal swamps and vast ice sheets; been inhabited by the earliest complex life forms, dinosaurs, and finally, witnessed the evolution of humans to a level where they now utilise and change the natural environment to meet their societal and economic needs. Evidence of this journey is recorded in the landscape and the rocks and sediments beneath our feet, and this article provides an overview of these events and the themed contributions to this Special Issue of Proceedings of the Geologists’ Association, which focuses on ‘The Geology of England – critical examples of Earth History’. Rather than being a stratigraphic account of English geology, this paper and the Special Issue attempts to place the Geology of England within the broader context of key ‘shifts’ and ‘tipping points’ that have occurred during Earth History. 1. Introduction England, together with the wider British Isles, is blessed with huge diversity of geology, reflected by the variety of natural landscapes and abundant geological resources that have underpinned economic growth during and since the Industrial Revolution. Industrialisation provided a practical impetus for better understanding the nature and pattern of the geological record, reflected by the publication in 1815 of the first geological map of Britain by William Smith (Winchester, 2001), and in 1835 by the founding of a national geological survey.
    [Show full text]
  • Hydrographic Development of the Aral Sea During the Last 2000 Years Based on a Quantitative Analysis of Dinoflagellate Cysts
    Palaeogeography, Palaeoclimatology, Palaeoecology 234 (2006) 304–327 www.elsevier.com/locate/palaeo Hydrographic development of the Aral Sea during the last 2000 years based on a quantitative analysis of dinoflagellate cysts P. Sorrel a,b,*, S.-M. Popescu b, M.J. Head c,1, J.P. Suc b, S. Klotz b,d, H. Oberha¨nsli a a GeoForschungsZentrum, Telegraphenberg, D-14473 Potsdam, Germany b Laboratoire Pale´oEnvironnements et Pale´obioSphe`re (UMR CNRS 5125), Universite´ Claude Bernard—Lyon 1, 27-43, boulevard du 11 Novembre, 69622 Villeurbanne Cedex, France c Department of Geography, University of Cambridge, Downing Place, Cambridge CB2 3EN, UK d Institut fu¨r Geowissenschaften, Universita¨t Tu¨bingen, Sigwartstrasse 10, 72070 Tu¨bingen, Germany Received 30 June 2005; received in revised form 4 October 2005; accepted 13 October 2005 Abstract The Aral Sea Basin is a critical area for studying the influence of climate and anthropogenic impact on the development of hydrographic conditions in an endorheic basin. We present organic-walled dinoflagellate cyst analyses with a sampling resolution of 15 to 20 years from a core retrieved at Chernyshov Bay in the NW Large Aral Sea (Kazakhstan). Cysts are present throughout, but species richness is low (seven taxa). The dominant morphotypes are Lingulodinium machaerophorum with varied process length and Impagidinium caspienense, a species recently described from the Caspian Sea. Subordinate species are Caspidinium rugosum, Romanodinium areolatum, Spiniferites cruciformis, cysts of Pentapharsodinium dalei, and round brownish protoper- idiniacean cysts. The chlorococcalean algae Botryococcus and Pediastrum are taken to represent freshwater inflow into the Aral Sea. The data are used to reconstruct salinity as expressed in lake level changes during the past 2000 years.
    [Show full text]
  • Geology: Ordovician Paleogeography and the Evolution of the Iapetus Ocean
    Ordovician paleogeography and the evolution of the Iapetus ocean Conall Mac Niocaill* Department of Geological Sciences, University of Michigan, 2534 C. C. Little Building, Ben A. van der Pluijm Ann Arbor, Michigan 48109-1063. Rob Van der Voo ABSTRACT thermore, we contend that the combined paleomagnetic and faunal data ar- Paleomagnetic data from northern Appalachian terranes identify gue against a shared Taconic history between North and South America. several arcs within the Iapetus ocean in the Early to Middle Ordovi- cian, including a peri-Laurentian arc at ~10°–20°S, a peri-Avalonian PALEOMAGNETIC DATA FROM IAPETAN TERRANES arc at ~50°–60°S, and an intra-oceanic arc (called the Exploits arc) at Displaced terranes occur along the extent of the Appalachian-Cale- ~30°S. The peri-Avalonian and Exploits arcs are characterized by Are- donian orogen, although reliable Ordovician paleomagnetic data from Ia- nigian to Llanvirnian Celtic fauna that are distinct from similarly aged petan terranes have only been obtained from the Central Mobile belt of the Toquima–Table Head fauna of the Laurentian margin, and peri- northern Appalachians (Table 1). The Central Mobile belt separates the Lau- Laurentian arc. The Precordillera terrane of Argentina is also charac- rentian and Avalonian margins of Iapetus and preserves remnants of the terized by an increasing proportion of Celtic fauna from Arenig to ocean, including arcs, ocean islands, and ophiolite slivers (e.g., Keppie, Llanvirn time, which implies (1) that it was in reproductive communi- 1989). Paleomagnetic results from Arenigian and Llanvirnian volcanic units cation with the peri-Avalonian and Exploits arcs, and (2) that it must of the Moreton’s Harbour Group and the Lawrence Head Formation in cen- have been separate from Laurentia and the peri-Laurentian arc well tral Newfoundland indicate paleolatitudes of 11°S (Table 1), placing them before it collided with Gondwana.
    [Show full text]
  • 2012-Ruiz-Martinez-Etal-EPSL.Pdf
    Earth and Planetary Science Letters 331-332 (2012) 67–79 Contents lists available at SciVerse ScienceDirect Earth and Planetary Science Letters journal homepage: www.elsevier.com/locate/epsl Earth at 200 Ma: Global palaeogeography refined from CAMP palaeomagnetic data Vicente Carlos Ruiz-Martínez a,b,⁎, Trond H. Torsvik b,c,d,e, Douwe J.J. van Hinsbergen b,c, Carmen Gaina b,c a Departamento de Geofísica y Meteorología, Facultad de Física, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid, Spain b Center for Physics of Geological Processes, University of Oslo, 0316 Oslo, Norway c Center of Advanced Study, Norwegian Academy of Science and Letters, 0271 Oslo, Norway d Geodynamics, NGU, N-7491 Trondheim, Norway e School of Geosciences, University of the Witwatersrand, WITS, 2050, South Africa article info abstract Article history: The Central Atlantic Magmatic Province was formed approximately 200 Ma ago as a prelude to the breakup of Received 21 November 2011 Pangea, and may have been a cause of the Triassic–Jurassic mass extinction. Based on a combination of (i) a Received in revised form 26 January 2012 new palaeomagnetic pole from the CAMP related Argana lavas (Moroccan Meseta Block), (ii) a global compila- Accepted 2 March 2012 tion of 190–210 Ma poles, and (iii) a re-evaluation of relative fits between NW Africa, the Moroccan Meseta Available online xxxx Block and Iberia, we calculate a new global 200 Ma pole (latitude=70.1° S, longitude=56.7° E and A95 =2.7°; Editor: P. DeMenocal N=40 poles; NW Africa co-ordinates). We consider the palaeomagnetic database to be robust at 200±10 Ma, which allows us to craft precise reconstructions near the Triassic–Jurassic boundary: at this very important Keywords: time in Earth history, Pangea was near-equatorially centered, the western sector was dominated by plate conver- palaeomagnetism gence and subduction, while in the eastern sector, the Palaeotethys oceanic domain was almost consumed palaeogeography because of a widening Neothethys.
    [Show full text]
  • Glacial Geomorphology☆ John Menzies, Brock University, St
    Glacial Geomorphology☆ John Menzies, Brock University, St. Catharines, ON, Canada © 2018 Elsevier Inc. All rights reserved. This is an update of H. French and J. Harbor, 8.1 The Development and History of Glacial and Periglacial Geomorphology, In Treatise on Geomorphology, edited by John F. Shroder, Academic Press, San Diego, 2013. Introduction 1 Glacial Landscapes 3 Advances and Paradigm Shifts 3 Glacial Erosion—Processes 7 Glacial Transport—Processes 10 Glacial Deposition—Processes 10 “Linkages” Within Glacial Geomorphology 10 Future Prospects 11 References 11 Further Reading 16 Introduction The scientific study of glacial processes and landforms formed in front of, beneath and along the margins of valley glaciers, ice sheets and other ice masses on the Earth’s surface, both on land and in ocean basins, constitutes glacial geomorphology. The processes include understanding how ice masses move, erode, transport and deposit sediment. The landforms, developed and shaped by glaciation, supply topographic, morphologic and sedimentologic knowledge regarding these glacial processes. Likewise, glacial geomorphology studies all aspects of the mapped and interpreted effects of glaciation both modern and past on the Earth’s landscapes. The influence of glaciations is only too visible in those landscapes of the world only recently glaciated in the recent past and during the Quaternary. The impact on people living and working in those once glaciated environments is enormous in terms, for example, of groundwater resources, building materials and agriculture. The cities of Glasgow and Boston, their distinctive street patterns and numerable small hills (drumlins) attest to the effect of Quaternary glaciations on urban development and planning. It is problematic to precisely determine when the concept of glaciation first developed.
    [Show full text]
  • PALAEOGEOGRAPHY, PALAEOCLIMATOLOGY, PALAEOECOLOGY an International Journal for the Geo-Sciences
    PALAEOGEOGRAPHY, PALAEOCLIMATOLOGY, PALAEOECOLOGY An International Journal for the Geo-Sciences AUTHOR INFORMATION PACK TABLE OF CONTENTS XXX . • Description p.1 • Audience p.1 • Impact Factor p.1 • Abstracting and Indexing p.2 • Editorial Board p.2 • Guide for Authors p.4 ISSN: 0031-0182 DESCRIPTION . Palaeogeography, Palaeoclimatology, Palaeoecology is an international medium for the publication of high quality and multidisciplinary, original studies and comprehensive reviews in the field of palaeo-environmental geology including palaeoclimatology. Please note that palaeogeographical and plate tectonic papers are considered to be outside the scope of the journal, and as such we kindly request that papers of this nature are not submitted. The journal aims at bringing together data with global implications from research in the many different disciplines involved in palaeo-environmental investigations. By cutting across the boundaries of established sciences, it provides an interdisciplinary forum where issues of general interest can be discussed. Benefits to authors We also provide many author benefits, such as free PDFs, a liberal copyright policy, special discounts on Elsevier publications and much more. Please click here for more information on our author services. Please see our Guide for Authors for information on article submission. If you require any further information or help, please visit our Support Center AUDIENCE . Palaeontologists, Sedimentologists, Marine Geologists, Quaternary Geologists. IMPACT FACTOR . 2020: 3.318 ©
    [Show full text]
  • Relationships Between Palaeogeography and Opal Occurrence in Australia: a Data-Mining Approach
    Computers & Geosciences 56 (2013) 76–82 Contents lists available at SciVerse ScienceDirect Computers & Geosciences journal homepage: www.elsevier.com/locate/cageo Relationships between palaeogeography and opal occurrence in Australia: A data-mining approach T.C.W. Landgrebe n, A. Merdith, A. Dutkiewicz, R.D. Muller¨ The University of Sydney, School of Geosciences, Madsen Building, NSW 2006 Sydney, Australia article info abstract Article history: Age-coded multi-layered geological datasets are becoming increasingly prevalent with the surge in Received 6 November 2012 open-access geodata, yet there are few methodologies for extracting geological information and Received in revised form knowledge from these data. We present a novel methodology, based on the open-source GPlates 6 February 2013 software in which age-coded digital palaeogeographic maps are used to ‘‘data-mine’’ spatio-temporal Accepted 9 February 2013 patterns related to the occurrence of Australian opal. Our aim is to test the concept that only a Available online 16 February 2013 particular sequence of depositional/erosional environments may lead to conditions suitable for the Keywords: formation of gem quality sedimentary opal. Time-varying geographic environment properties are Data-mining extracted from a digital palaeogeographic dataset of the eastern Australian Great Artesian Basin (GAB) Spatio-temporal analysis at 1036 opal localities. We obtain a total of 52 independent ordinal sequences sampling 19 time slices Palaeogeography from the Early Cretaceous to the present-day. We find that 95% of the known opal deposits are tied to Opal Association rules only 27 sequences all comprising fluvial and shallow marine depositional sequences followed by a Great Artesian Basin prolonged phase of erosion.
    [Show full text]
  • Palaeozoic Palaeogeography and Biogeography Palaeozoic Palaeogeography and Biogeography
    Palaeozoic Palaeogeography and Biogeography Palaeozoic Palaeogeography and Biogeography EDITED BY W. S. McKERROW Department of Earth Sciences University of Oxford & C. R. SCOTESE Shell Development Company Houston, Texas Memoir No. 12 1990 Published by The Geological Society London THE GEOLOGICAL SOCIETY The Geological Society of London was founded in 1807 for the purpose of 'investigating the mineral structures of the earth'. It received its Royal Charter in 1825. The Society promotes all aspects of geological science by means of meetings, special lectures and courses, discussions, specialist groups, publications and library services. It is expected that candidates for Fellowship will be graduates in geology or another earth science, or have equivalent qualifications or experience. All Fellows are entitled to receive for their subscription one of the Society's three journals: The Quarterly Journal of Engineering Geology, the Journal of the Geological Society or Marine and Petroleum Geology. On payment of an additional sum on the annual subscription, members may obtain copies of another journal. Membership of the specialist groups is open to all Fellows without additional charge. Enquiries concerning Fellowship of the Society and membership of the specialist groups should be directed to the Executive Secretary, The Geological Society, Burlington House, Piccadilly, London WlV 0JU. Published by the Geological Society from: The Geological Society Publishing House Unit 7 Brassmill Enterprise Centre Brassmill Lane Bath Avon BA1 3JN UK (Orders: Tel. 0225 445046) First published 1990 Reprinted 1994 The Geological Society 1990. All rights reserved. No reproduction, copy or transmission of this publication may be made without written permission. No paragraph of this publication may be reproduced, copied or transmitted save with the written permission or in accordance with the provisions of the Copyright Act 1956 (as Amended) or under the terms of any licence permit- ting limited copying issued by the Copyright Licensing Agency, 33-34 Alfred Place, London WC1E 7DP.
    [Show full text]
  • Download File
    Contents lists available at ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo Pangea B and the Late Paleozoic Ice Age ⁎ D.V. Kenta,b, ,G.Muttonic a Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA b Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA c Dipartimento di Scienze della Terra 'Ardito Desio', Università degli Studi di Milano, via Mangiagalli 34, I-20133 Milan, Italy ARTICLE INFO ABSTRACT Editor: Thomas Algeo The Late Paleozoic Ice Age (LPIA) was the penultimate major glaciation of the Phanerozoic. Published compi- Keywords: lations indicate it occurred in two main phases, one centered in the Late Carboniferous (~315 Ma) and the other Late Paleozoic Ice Age in the Early Permian (~295 Ma), before waning over the rest of the Early Permian and into the Middle Permian Pangea A (~290 Ma to 275 Ma), and culminating with the final demise of Alpine-style ice sheets in eastern Australia in the Pangea B Late Permian (~260 to 255 Ma). Recent global climate modeling has drawn attention to silicate weathering CO2 Greater Variscan orogen consumption of an initially high Greater Variscan edifice residing within a static Pangea A configuration as the Equatorial humid belt leading cause of reduction of atmospheric CO2 concentrations below glaciation thresholds. Here we show that Silicate weathering CO2 consumption the best available and least-biased paleomagnetic reference poles place the collision between Laurasia and Organic carbon burial Gondwana that produced the Greater Variscan orogen in a more dynamic position within a Pangea B config- uration that had about 30% more continental area in the prime equatorial humid belt for weathering and which drifted northward into the tropical arid belt as it transformed to Pangea A by the Late Permian.
    [Show full text]
  • The Palaeoclimatology, Palaeoecology and Palaeoenvironmental Analysis of Mass Extinction Events
    Palaeogeography, Palaeoclimatology, Palaeoecology 232 (2006) 190–213 www.elsevier.com/locate/palaeo The palaeoclimatology, palaeoecology and palaeoenvironmental analysis of mass extinction events Richard J. Twitchett School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK Received 1 December 2004; received in revised form 22 April 2005; accepted 23 May 2005 Abstract Although there is a continuum in magnitude of diversity loss between the smallest and largest biotic crisis, typically most authors refer to the largest five Phanerozoic events as bmass extinctionsQ. In the past 25 years the study of these mass extinction events has increased dramatically, with most focus being on the Cretaceous–Tertiary (K–T) event, although study of the end- Permian event (in terms of research output) is likely to surpass that of the K–T in the next few years. Many aspects of these events are still debated and there is no common cause or single set of climatic or environmental changes common to these five events, although all are associated with evidence for climatic change. The supposed extinction-causing environmental changes resulting from extraterrestrial impact are, at best, equivocal and are unlikely to have been of sufficient intensity or geographic extent to cause global extinction. The environmental consequences of rapid global warming (such as ocean stagnation, reduced upwelling and loss of surface productivity) are considered to have been particularly detrimental to the biosphere in the geological past. The first phase of the Late Ordovician event is clearly linked to rapid global cooling. Palaeoecological studies have demonstrated that feeding mechanism is a key trait that enhances survival chances, with selective detritivores and omnivores usually faring better than suspension feeders or grazers.
    [Show full text]
  • Phanerozoic Polar Wander, Palaeogeography and Dynamics
    Earth-Science Reviews 114 (2012) 325–368 Contents lists available at SciVerse ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Phanerozoic polar wander, palaeogeography and dynamics Trond H. Torsvik a,b,c,d,⁎, Rob Van der Voo a,e, Ulla Preeden f, Conall Mac Niocaill g, Bernhard Steinberger h,a,b, Pavel V. Doubrovine a,b, Douwe J.J. van Hinsbergen a,b, Mathew Domeier e,b, Carmen Gaina a,b, Eric Tohver i, Joseph G. Meert j, Phil J.A. McCausland k, L. Robin M. Cocks l a Center for Advanced Study, Norwegian Academy of Science and Letters, Drammensveien 78, 0271 Oslo, Norway b Center for Physics of Geological Processes (PGP), University of Oslo, Sem Sælands vei 24, NO-0316 Oslo, Norway c Geodynamics, Geological Survey of Norway, Leiv Eirikssons vei 39, 7491Trondheim, Norway d School of Geosciences, University of the Witwatersrand, WITS 2050 Johannesburg, South Africa e Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109‐1005, USA f Department of Geology, University of Tartu, Ravila 14A, 50411 Tartu, Estonia g Department of Earth Sciences, South Parks Road, Oxford OX1 3AN, UK h Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Section 2.5, Geodynamic Modelling, Helmholtzstrasse 6, H6 117, 14467 Potsdam, Germany i School of Earth and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia j Department of Geological Sciences, 355 Williamson Hall, University of Florida, Gainesville, FL 32611, USA k Department
    [Show full text]
  • Western Interior Seaway
    () . Paleogeo.graphy of the Late Cretaceous of the Western Interior otMfddle North America+­ j?'oal .Blstribution anct,Sedimen~cumulation By Laura N. Robinson Roberts and Mark A. Kirschbaum U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1561 UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1995 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Gordon P. Eaton, Director For sale by U.S. Geological Survey, Information Services Box 25286, Federal Center Denver, CO 80225 Any use of trade, product, or finn names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government Library of Congress Cataloging-in-Publication Data Roberts, Laura N. Robinson. Paleogeography of the Late Cretaceous of the western interior of middle North America : coal distribution and sediment accumulation I by Laura N. Robinson Roberts and Mark A. Kirschbaum. p. em.- (U.S. Geological Survey professional paper ; 1561) Includes bibliographical references. Supt. of Docs. no.: I 19.16: 1561 1. Paleogeography-Cretaceous. 2. Paleogeography-West (U.S.). 3. Coal­ Geology-West (U.S.). I. Kirschbaum, Mark A. II. Title. III. Series. QE50 1.4.P3R63 1995 553.2'1'0978-dc20 94-39032 CIP CONTENTS Abstract........................................................................................................................... 1" Introduction ................................................................................................................... Western Interior Seaway ... .. ... ... ... .. .. ..
    [Show full text]