DOCSLIB.ORG

Read Ebook {PDF EPUB} Evolutionary Catastrophes the Science Of

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Read Ebook {PDF EPUB} Evolutionary Catastrophes the Science Of Read Ebook {PDF EPUB} Evolutionary Catastrophes The Science of Mass Extinction by Vincent Courtillot Evolutionary Catastrophes: The Science of Mass Extinction by Vincent Courtillot. Our systems have detected unusual traffic activity from your network. Please complete this reCAPTCHA to demonstrate that it's you making the requests and not a robot. If you are having trouble seeing or completing this challenge, this page may help. If you continue to experience issues, you can contact JSTOR support. Block Reference: #74237df0-cf92-11eb-93b0-af62c0663030 VID: #(null) IP: 116.202.236.252 Date and time: Thu, 17 Jun 2021 17:35:48 GMT. ISBN 13: 9780521583923. Evolutionary Catastrophes: The Science of Mass Extinction. Courtillot, Vincent. This specific ISBN edition is currently not available. Why did the dinosaurs and two-thirds of all living species vanish from the face of the Earth sixty-five million years ago? Throughout the history of life a small number of catastrophic events have caused mass extinction, and changed the path of evolution forever. Two main theories have emerged to account for these dramatic events: asteroid impact, and massive volcanic eruptions, both leading to nuclear-like winter. In recent years, the impact hypothesis has gained precedence, but Vincent Courtillot suggests that cataclysmic volcanic activity can be linked not only to the K-T mass extinction, but to most of the main mass extinction events in the history of the Earth. Courtillot's book debunks some of the myths surrounding one of the most controversial arguments in science. This story will fascinate everyone interested in the history of life and death on our planet. "synopsis" may belong to another edition of this title. Why did the dinosaurs and two-thirds of all living species vanish from the face of the Earth sixty-five million years ago? Throughout the history of life a small number of catastrophic events have caused mass extinction, and changed the path of evolution forever. Vincent Courtillot suggests that cataclysmic volcanic activity can be linked to most of these dramatic events. Courtillot's book debunks some of the myths surrounding one of science's most controversial arguments, and will fascinate everyone interested in the history of life and death on our planet. About the Author : Vincent Courtillot is Professor of Geophysics at the University of Paris, heads a research group at Institut de Physique du Globe and is special advisor to the French Ministry of National Education, Research and Technology. Evolutionary Catastrophes : The Science of Mass Extinction. "Science is not a democracy, and there is no room for political compromise," writes Frankel in reference to the raging debate over what caused the extinction of the dinosaurs. In one camp are the . Читать весь отзыв. Другие издания - Просмотреть все. Об авторе (1999) Vincent Courtillot is Professor of Geophysics at the University of Paris, heads a research group at Institut de Physique du Globe and is special advisor to the French Ministry of National Education, Research and Technology. Evolutionary Catastrophes: The Science Of Mass Extinction. Mass extinction and cataclysmic volcanic activity: will fascinate everyone interested in the history of life and death on our planet. "synopsis" may belong to another edition of this title. One of the greatest "detective" stories in the history of the Earth is the dinosaur "whodunnit". For a long time it has been known that dinosaurs, pterosaurs (flying reptiles) and several groups of marine reptiles all died out at the end of Cretaceous times 65 million years ago. There are many questions about this extinction event. For instance, what caused their demise? Over the last decade the most fingered culprit has been an extra-terrestrial--an asteroid that whammed into Mexico's Yucatan peninsula at just the right time. A simple and spectacular resolution, you would think the outcome of the trial would be a forgone conclusion. But when the expert witnesses are called it all begins to become less clear cut. Whilst there is no doubt an asteroid did hit the Earth at the time, the effects of its impact do not seem to amount to as much as was originally thought. However, there were plenty of other possible perpetrators around at the time which were powerful enough to cause global mayhem. Evolutionary Catastrophes is a translation and update of an excellent presentation of the case for the most likely accomplice or perhaps main perpetrator--cataclysmic volcanism. Outpourings of "greenhouse" gases and volcanic dust cause climate change which has a knock-on effect through the plants, plant eaters to the meat eaters, through the whole food chain. As a professor of geophysics in the University of Paris, Vincent Courtillot is an expert witness and well placed to guide us through the more arcane aspects of the "palaeoforensics" of the case. He manages to make his statement in language suitable for the general reader and there is an excellent glossary and index to help with more technical matters. Courtillot extends his analysis to the other major extinction events in Earth's history and shows how massive outpourings of lavas coincide with them all, especially the biggest of all the Permian/Triassic extinction around 250 million years ago. Arguments over the interpretation of the palaeoforensic details will go on. As Vincent Courtillot says "no doubt the party will go on" and "many secrets remain to be brought to light". To get the argument in favour of extra-terrestrial impacts as the cause for most extinction events see Charles Frankel's The End of the Dinosaurs . -- Douglas Palmer. '. a beautifully written little book that, once picked up, is impossible to put down.' Geoscientist. ' . watch this space and read this book.' Bob White, New Scientist. 'The book is very readable and provides a clear and concise picture for anyone interested in the subject. The text is well written and supported by clear footnotes where necessary and a comprehensive glossary . [I] recommend this book for those at any stage in their studies or knowledge. It is written for a general audience but should not be missed by professionals.' Mike Hermolle, Open University Geological Society Journal. '[Vincent Coutillot] has done a superb job! A balanced and fair treatment of a complex of information, misinformation, and perhaps even disinformation. Although written for a general audience, this book should be obligatory reading for all professionals involved in the controversies surrounding the causes of mass extinction. Even the most committed will find their outlook broadened.' David M. Raup, Formerly Professor of Paleontology, University of Chicago, and author of Extinction, Bad Genes or Bad Luck? (Norton, 1991) Praise for the original French edition: 'A real scientific thriller . Vincent Courtillot brilliantly presents the stormy genesis of an original, unifying theory on the origin of the great biological extinctions which have marked the history of the earth.' Pascal Tassy, La Recherche. Praise for the original French edition: '. a vividly written book which . clarifies many points that have been shrouded in darkness up until now'. French Edition of Scientific American. Praise for the original French edition: '. a science book and an adventure book'. Ciel et Espace. Praise for the original French edition: 'To be read by all paleontology, geology and ecology enthusiasts.' Sciences et Avenir. 'Courtillot makes an excellent case for other mass extinctions being almost certainly related to cataclysmic volcanism. A well-written and well- reasoned book, essential for any library.' M. A. Wilson, Choice. 'It is rare to find a first-rate geoscientist who can write a first-rate popular book on science, but Professor Courtillot is one such . a lively exposition of the idea that mantle processes cause major stress to ecosystems. It is beautifully written . The pace is fast, but the data well explained and authoritatively considered . Anyone with an interest in mass extinctions or in the episodic and catastrophic nature of teh Earth's internal processes should rush out and read this book. It is a rewarding experience.' Susan Rigby, University of Edinburgh..
Load more

Recommended publications
  • Vincent COURTILLOT - Publications
    1 Vincent COURTILLOT - Publications Books (or Book Chapters) 1- La dérive des continents V. COURTILLOT et P. TAPPONNIER In La mémoire de la Terre, par A. ADOUTTE,…,V.COURTILLOT,…. , 115-125, Seuil, Paris, 1992. 2- La Vie en Catastrophes V. COURTILLOT 279 pp., Fayard, Paris, 1995. (translated in German and English, 1999) 3- Evolutionnary Catastrophes: The Science of Mass Extinction V. COURTILLOT 171 pp., Cambridge University Press, Cambridge, 1999. (translation and update) Paperback in 2002 4- La dynamique du Globe contrôle-t’elle l’évolution des espèces ? V. COURTILLOT in Qu’est ce que la vie ? Y. Michaud ed., Université de tous les savoirs, vol. 1, pp. 149-162, Editions Odile Jacob, Paris, 2000. 5- L’observation du globe V. COURTILLOT in Le renouvellement de l’observation dans les sciences, Y. Michaud ed., Université de tous les savoirs, pp. 115-118, Editions Odile Jacob, Paris, 2003. 6- Volcanisme et évolution de la vie sur terre V. COURTILLOT in Qu’est ce que la diversité de la vie ?, Y. Michaud ed., Université de tous les savoirs, pp. 133-145, Editions Odile Jacob, Paris, 2003. 7- Nouveau Voyage au Centre de la Terre (provisional title) V. COURTILLOT Editions Odile Jacob, Paris,to be published September 2009. Articles for the public at large (Scientific American type) 1- Les panaches, moteur de la dérive des continents V. COURTILLOT La Recherche, 32, 270-272 (1973) 2- Crise de l'énergie: la solution géothermique 2 V. COURTILLOT La Recherche, 35, 586-587 (1973) 3- Volcanisme et tectonique en Islande P. TAPPONNIER, V. COURTILLOT La Recherche, 37, (1973) 4- La prédiction des tremblements de terre V.
    [Show full text]
  • C.V. De Vincent Courtillot, Membre De L'académie Des Sciences
    Vincent Courtillot Élu Membre le 18 novembre 2003 dans la section Sciences de l'univers Vincent Courtillot, né en 1948, ancien élève de l'École des mines de Paris, docteur ès sciences, diplômé de l'université de Stanford (Californie), est professeur de géophysique à l'université Denis- Diderot à Paris. Il a enseigné à l'université de Stanford, Santa Barbara et au California Institute of Technology (Caltech). Il a été directeur de la recherche et des études doctorales au ministère de l'Éducation nationale, conseiller spécial du Ministre de l'Éducation nationale, de la recherche et de la technologie (1997-1998), puis directeur de la recherche (1998-2001). Il a fondé et présidé le premier Conseil scientifique de la Ville de Paris (2002-2009). Il est le directeur sortant de l'Institut de Physique du Globe de Paris (2004-2010). Géophysicien, Vincent Courtillot est un spécialiste du paléomagnétisme et de la géodynamique. Il a apporté de nombreux résultats sur les déformations continentales, les épanchements basaltiques ainsi que leurs conséquences et a très fortement contribué aux grandes études de reconstruction paléogéographique. Les premiers travaux de V. Courtillot portent sur la théorie des champs de potentiel et les variations temporelles du champ magnétique terrestre (découverte des sauts d’accélération séculaire). La réalisation d’un levé aéromagnétique en Afar lui permet de découvrir le premier exemple de propagation d’un rift en milieu continental. En 1980 il fonde avec J.P. Pozzi le laboratoire de paléomagnétisme de l’IPGP et il s’associe ensuite avec P.Y. Gillot pour cofonder à l’université Paris Sud – Orsay un laboratoire de géochronologie multi-techniques.
    [Show full text]
  • The ``Van Zijl'' Jurassic Geomagnetic Reversal Revisited
    The “van Zijl” Jurassic geomagnetic reversal revisited Maud Moulin, Vincent Courtillot, Frédéric Fluteau, Jean-Pierre Valet To cite this version: Maud Moulin, Vincent Courtillot, Frédéric Fluteau, Jean-Pierre Valet. The “van Zijl” Jurassic ge- omagnetic reversal revisited. Geochemistry, Geophysics, Geosystems, AGU and the Geochemical Society, 2012, 13 (3), 10.1029/2011GC003910. hal-02139522 HAL Id: hal-02139522 https://hal.archives-ouvertes.fr/hal-02139522 Submitted on 24 May 2019 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. Article Volume 13, Number 3 13 March 2012 Q03010, doi:10.1029/2011GC003910 ISSN: 1525-2027 The “van Zijl” Jurassic geomagnetic reversal revisited Maud Moulin Equipe de Paléomagnétisme, Institut de Physique du Globe, UMR 7154, Sorbonne Paris Cité, F-75005 Paris, France Sciences de la Terre, de l’Environnement et des Planètes, Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France Now at Département de Géologie, Université Jean Monnet, F-42023 Saint Etienne, France ([email protected]) Vincent Courtillot, Frédéric Fluteau, and Jean-Pierre Valet Equipe de Paléomagnétisme, Institut de Physique du Globe, UMR 7154, Sorbonne Paris Cité, F-75005 Paris, France Sciences de la Terre, de l’Environnement et des Planètes, Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France [1] We have collected two new detailed records of what could be the second oldest well documented reversal, the “van Zijl” Jurassic (180 Ma) reversal recorded in the thick basalt sequences of the Karoo large igneous province in Lesotho and South Africa.
    [Show full text]
  • Apparent and True Polar Wander and the Geometry of the Geomagnetic
    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. B11, 2300, doi:10.1029/2000JB000050, 2002 Correction published 10 October 2003 Apparent and true polar wander and the geometry of the geomagnetic field over the last 200 Myr Jean Besse and Vincent Courtillot Laboratoire de Pale´omagne´tisme, UMR 7577, Institut de Physique du Globe de Paris, Paris, France Received 8 November 2000; revised 15 January 2002; accepted 20 January 2002; published 15 November 2002. [1] We have constructed new apparent polar wander paths (APWPs) for major plates over the last 200 Myr. Updated kinematic models and selected paleomagnetic data allowed us to construct a master APWP. A persistent quadrupole moment on the order of 3% of the dipole over the last 200 Myr is suggested. Paleomagnetic and hot spot APW are compared, and a new determination of ‘‘true polar wander’’ (TPW) is derived. Under the hypothesis of fixed Atlantic and Indian hot spots, we confirm that TPW is episodic, with periods of (quasi) standstill alternating with periods of faster TPW (in the Cretaceous). The typical duration of these periods is on the order of a few tens of millions of years with wander rates during fast tracks on the order of 30 to 50 km/Myr. A total TPW of some 30° is suggested for the last 200 Myr. We find no convincing evidence for episodes of superfast TPW such as proposed recently by a number of authors. Comparison over the last 130 Myr of TPW deduced from hot spot tracks and paleomagnetic data in the Indo-Atlantic hemisphere with an independent determination for the Pacific plate supports the idea that, to first order, TPW is a truly global feature of Earth dynamics.
    [Show full text]
  • Convective Patterns Under the Indo-Atlantic T Box R
    Earth and Planetary Science Letters 239 (2005) 233–252 www.elsevier.com/locate/epsl Convective patterns under the Indo-Atlantic T box r Anne Davaille a,*, Ele´onore Stutzmann a, Grac¸a Silveira b,c, Jean Besse a, Vincent Courtillot a a Institut de Physique du Globe and CNRS, 4 Place Jussieu, 75252 Paris cedex 05, France b Centro de Geofı´sica da Universidade de Lisboa Edifı´cio C8, Campo Grande, 1749-016 LISBOA, Portugal c Instituto Superior de Engengaria de Lisboa Avenida Conselheiro Emı´dio Navarro, 1949-014 LISBOA, Portugal Received 4 January 2005; received in revised form 23 July 2005; accepted 27 July 2005 Available online 10 October 2005 Editor: S. King Abstract Using fluid mechanics, we reinterpret the mantle images obtained from global and regional tomography together with geochemical, geological and paleomagnetic observations, and attempt to unravel the pattern of convection in the Indo-Atlantic bboxQ and its temporal evolution over the last 260 Myr. The T box r presently contains a) a broad slow seismic anomaly at the CMB which has a shape similar to Pangea 250 Myr ago, and which divides into several branches higher in the lower mantle, b) a bsuperswellQ centered on the western edge of South Africa, c) at least 6 bprimary hotspotsQ with long tracks related to traps, and d) numerous smaller hotspots. In the last 260 Myr, this mantle box has undergone 10 trap events, 7 of them related to continental breakup. Several of these past events are spatially correlated with present-day seismic anomalies and/or upwellings. Laboratory experiments show that superswells, long-lived hotspot tracks and traps may represent three evolutionary stages of the same phenomenon, i.e.
    [Show full text]
  • Resolving the Timing of Events Around the Cretaceous-Paleogene Boundary
    Resolving the timing of events around the Cretaceous-Paleogene Boundary By Courtney Jean Sprain A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Earth and Planetary Science in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Paul R. Renne, Chair Professor Mark A. Richards Professor William A. Clemens Spring 2017 Resolving the timing of events around the Cretaceous-Paleogene Boundary Copyright 2017 by Courtney Jean Sprain Abstract Resolving the timing of events around the Cretaceous-Paleogene Boundary by Courtney Jean Sprain Doctor of Philosophy in Earth and Planetary Science University of California, Berkeley Professor Paul R. Renne, Chair Despite decades of study, the exact cause of the Cretaceous-Paleogene boundary (KPB) mass extinction remains contentious. Hypothesized scenarios center around two main environmental perturbations: voluminous (>106 km3) volcanic eruptions from the Deccan Traps in modern-day India, and the large impact recorded by the Chicxulub crater. The impact hypothesis has gained broad support, bolstered by the discoveries of iridium anomalies, shocked quartz, and spherules at the KPB worldwide, which are contemporaneous with the Chicxulub impact structure. However, evidence for protracted extinctions, particularly in non-marine settings, and paleoenvironmental change associated with climatic swings before the KPB, challenge the notion that the impact was the sole cause of the KPB mass extinction. Despite forty years of study, the relative importance of each of these events is unclear, and one key inhibitor is insufficient resolution of existing geochronology. In this dissertation, I present work developing a high-precision global chronologic framework for the KPB that outlines the temporal sequence of biotic changes (both within the terrestrial and marine realms), climatic changes, and proposed perturbations (i.e.
    [Show full text]
  • Evolutionary Catastrophes: the Science of Mass Extinction Vincent Courtillot Frontmatter More Information
    Cambridge University Press 0521583926 - Evolutionary Catastrophes: The Science of Mass Extinction Vincent Courtillot Frontmatter More information Evolutionary Catastrophes Why did the dinosaurs and two-thirds of all living species vanish from the face of the Earth sixty-five million years ago? Throughout the history of life, a small number of cat- astrophic events have caused mass extinction and changed the path of evolution forever. Two main theories have emerged to account for these dramatic events: asteroid impact and massive volcanic eruptions, both leading to nuclear-like winter. In recent years, the impact hypothesis has gained precedence, but Vincent Courtillot suggests that cataclysmic volcanic activity can be linked not only to the K–T mass extinction but also to most of the main mass extinction events in the history of the Earth. Courtillot’s book explodes some of the myths surrounding one of the most controversial arguments in science. It shows among other things that the impact and volcanic scenarios may not be mutually exclusive. This story will fascinate everyone interested in the history of life and death on our planet. VINCENT COURTILLOT is a graduate of the Paris School of Mines, Stanford University, and University of Paris. He is Professor of Geophysics at the University of Paris (Denis Diderot) and heads a research group at Institut de Physique du Globe. His work has focused on time variations of the Earth’s magnetic field, plate tectonics (continental rift- ing and collision), magnetic reversals, and flood basalts and their possible relation to mass extinctions. He has published papers in professional journals, and a book entitled La Vie en Catastrophes (Fayard, Paris, France, ).
    [Show full text]
  • Evolutionary Catastrophes: the Science of Mass Extinction Vincent Courtillot Frontmatter More Information
    Cambridge University Press 978-0-521-89118-9 - Evolutionary Catastrophes: The Science of Mass Extinction Vincent Courtillot Frontmatter More information Evolutionary Catastrophes Why did the dinosaurs and two-thirds of all living species vanish from the face of the Earth sixty-five million years ago? Throughout the history of life, a small number of cat- astrophic events have caused mass extinction and changed the path of evolution forever. Two main theories have emerged to account for these dramatic events: asteroid impact and massive volcanic eruptions, both leading to nuclear-like winter. In recent years, the impact hypothesis has gained precedence, but Vincent Courtillot suggests that cataclysmic volcanic activity can be linked not only to the K–T mass extinction but also to most of the main mass extinction events in the history of the Earth. Courtillot’s book explodes some of the myths surrounding one of the most controversial arguments in science. It shows among other things that the impact and volcanic scenarios may not be mutually exclusive. This story will fascinate everyone interested in the history of life and death on our planet. VINCENT COURTILLOT is a graduate of the Paris School of Mines, Stanford University, and University of Paris. He is Professor of Geophysics at the University of Paris (Denis Diderot) and heads a research group at Institut de Physique du Globe. His work has focused on time variations of the Earth’s magnetic field, plate tectonics (continental rift- ing and collision), magnetic reversals, and flood basalts and their possible relation to mass extinctions. He has published papers in professional journals, and a book entitled La Vie en Catastrophes (Fayard, Paris, France, ).
    [Show full text]
  • New, Tighter Timeline Confirms Ancient Volcanism Aligned with Dinosaurs' Extinction 18 December 2014
    New, tighter timeline confirms ancient volcanism aligned with dinosaurs' extinction 18 December 2014 comprised about 80-90 percent of the total volume of the Deccan Traps' lava flow and followed a substantially weaker first phase that began about 1 million years earlier. The results support the idea that the Deccan Traps played a role in the K-Pg extinction, and challenge the dominant theory that a meteorite impact near present-day Chicxulub, Mexico, was the sole cause of the extinction. The researchers suggest that the Deccan Traps eruptions and the Chicxulub impact need to be considered together when studying and modeling the K-Pg extinction event. The Deccan Traps' part in the K-Pg extinction is A definitive geological timeline from Princeton University consistent with the rest of Earth history, explained researchers shows that a series of massive eruptions 66 lead author Blair Schoene, a Princeton assistant million years ago in a primeval volcanic range in western professor of geosciences who specializes in India known as the Deccan Traps played a role in the geochronology. Four of the five largest extinction extinction event that claimed Earth's non-avian events in the last 500 million years coincided with dinosaurs, and challenges the dominant theory that a large volcanic eruptions similar to the Deccan meteorite impact was the sole cause of the extinction. Pictured above are the Deccan Traps near Traps. The K-Pg extinction is the only one that Mahabaleshwar, India. Credit: Gerta Keller, Department coincides with an asteroid impact, he said. of Geosciences "The precedent is there in Earth history that significant climate change and biotic turnover can result from massive volcanic eruptions, and A definitive geological timeline shows that a series therefore the effect of the Deccan Traps on late- of massive volcanic explosions 66 million years Cretaceous ecosystems should be considered," ago spewed enormous amounts of climate-altering Schoene said.
    [Show full text]
  • Evolutionalry Catastrophies
    Journal of Sedimentary Research An International Journal of SEPM Colin P. North and Kitty L. Milliken, Editors A.J. (Tom) van Loon, Associate Editor for Book Reviews Review accepted 22 August 2007 DOI: 10.2110/jsr.2007.008 Evolutionary Catastrophes S The Science of Mass Extinction, by Vincent Courtillot (translated by Joe McClinton), 2007. Cambridge University Press, The Edinburgh Building, Cambridge, CB2 2RU, United Kingdom. Paperback (hardback no longer available), 188 pages, 17 line diagrams, 4 halftones. Price GBP 15.99; USD 24.99. ISBN 0521891183. Who does not like horror stories? No wonder that also books on extermination of dinosaurs sell well. A first-hand description of the dispute on the causes of their extinction, initiated more than thirty years ago, with emotional intensity horrifying not less than the events 65 million years ago, is still available in paperback edition. Vincent Courtillot is a French paleomagnetist, highly respected not only in his own country, who had a good luck to work on the Deccan Traps in the proper time. This placed him among the prominent supporters of the volcanic cause of the Cretaceous/Tertiary dramatic changes in the biosphere. The description of how the conclusions were reached and confronted with views of the extraterrestrial party is vivid and instructive to non-geophysicists (I am among them). This is probably the main value of the book, contrary to its English title rather imprecisely describing its contents. Little is written in it about evolution, and the scientific level of its paleontological aspects is nicely expressed by an explanation in the glossary added to the book: “Bivalves: An animal, like a clam, that has two valves that open and shut (part of the mollusks).” Vincent Courtillot argued against the extraterrestrial cause of all the major extinction events in the Phanerozoic Earth history and for their connection with volcanism, but his arguments loose some consistency while referring to the topic story of dinosaurs.
    [Show full text]
  • Mantle Plumes Link Magnetic Superchrons to Phanerozoic Mass Depletion Events ⁎ Vincent Courtillot A, , Peter Olson B
    Earth and Planetary Science Letters 260 (2007) 495–504 www.elsevier.com/locate/epsl Mantle plumes link magnetic superchrons to phanerozoic mass depletion events ⁎ Vincent Courtillot a, , Peter Olson b a Institut de Physique du Globe de Paris, France b Earth and Planetary Sciences, Johns Hopkins University, United States Received 4 April 2007; received in revised form 21 May 2007; accepted 3 June 2007 Available online 12 June 2007 Editor: G.D. Price Abstract The four most recent large mass extinction events in the Phanerozoic – the Cretaceous–Tertiary (KT), the Triassic–Jurassic (TJ), and the Permo-Triassic (PT) and Guadalupian–Tatarian (GT) doublet – are associated with a major flood basalt eruption, with the timing of peak volcanic activity corresponding within measurement uncertainties to the extinction event. Three magnetic superchrons precede the four largest Phanerozoic extinctions. The Cretaceous Long Normal Superchron (duration ∼35 Myr) precedes the KT and the Permian Kiaman Long Reversed Superchron (∼50 Myr) precedes the PT–GT doublet. In addition, the newly recognized Ordovician Moyero Long Reversed Superchron (∼30 Myr) precedes the end-Ordovician extinction event. There is a 10–20 Myr delay between the end of each superchron and the subsequent mass depletion event, both of which represent distant outliers from their respective populations. We propose that deep mantle plumes link these seemingly unrelated phenomena. Long- term (∼200 Myr) variations in mantle convection possibly associated with the Wilson cycle induce temporal and spatial variations in heat flow at the core–mantle boundary. Polarity reversals are frequent when core heat flow is high and infrequent when it is low.
    [Show full text]
  • The Cretaceous–Tertiary Mass Extinction: Theories and Controversies
    Author E-Print 1/3/2012 THE CRETACEOUS–TERTIARY MASS EXTINCTION: THEORIES AND CONTROVERSIES GERTA KELLER Department of Geosciences, Princeton University, Princeton NJ 08544, U.S.A. e-mail: [email protected] ABSTRACT: The Cretaceous–Tertiary boundary (KTB) mass extinction is primarily known for the demise of the dinosaurs, the Chicxulub impact, and the frequently rancorous thirty-years-old controversy over the cause of this mass extinction. Since 1980 the impact hypothesis has steadily gained support, which culminated in 1990 with the discovery of the Chicxulub crater on Yucata´n claimed as the KTB impact site and ‘‘smoking gun’’ that virtually proved this hypothesis. In a perverse twist of fate, this discovery also began the decline of the impact hypothesis, because for the first time it could be tested directly based on the impact crater and impact ejecta in sediments throughout the Caribbean, Central America, and North America. Two decades of multidisciplinary studies amassed a database with a sum total that overwhelmingly reveals the Chicxulub impact as predating the KTB mass extinction in the impact-crater cores, in sections throughout northeastern Mexico and in Brazos River sections of Texas, U.S.A. This paper recounts the highlightsof the KTB controversy, the discovery of facts inconsistent with the impact hypothesis, and the resurgence of the Deccan volcanism hypothesis as the most likely cause for the mass extinction. KEY WORDS: Cretaceous–Tertiary, KTB, Mass Extinction, Chicxulub Impact, Deccan Volcanism, Impact-tsunami, Age of Chicxulub impact INTRODUCTION Keller et al., 2009b). Similar effects are predicted as a result of a large impact. Hybrid hypotheses have tried to link mass extinctions, Most mass extinctions over the past 500 million years in Earth’s volcanism, and impacts, with the latter triggering large-scale history occurred during times of major volcanic eruptions; some magmatism (Stothers et al., 1986; Rampino and Stothers, l988; occurred at times of multiple impacts (Fig.
    [Show full text]