Continental Rifted Margins 1. Gwenn Peron-Pinvidic

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      SCIENCES

       Geoscience, Field Director – Yves Lagabrielle

      Dynamics of the Continental Lithosphere, Subject Head – Sylvie Leroy

      Continental Rifted Margins 1

       Definition and Methodology

       Coordinated by

      Gwenn Peron-Pinvidic

First published 2022 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

      Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

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      John Wiley & Sons, Inc.

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      © ISTE Ltd 2022

      The rights of Gwenn Peron-Pinvidic to be identified as the author of this work have been asserted by her in accordance with the Copyright, Designs and Patents Act 1988.

      Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s), contributor(s) or editor(s) and do not necessarily reflect the views of ISTE Group.

      Library of Congress Control Number: 2021950855

      British Library Cataloguing-in-Publication Data

      A CIP record for this book is available from the British Library

      ISBN 978-1-78945-061-3

      ERC code:

      PE10 Earth System Science

      PE10_5 Geology, tectonics, volcanology

      PE10_7 Physics of earth’s interior, seismology, volcanology

      PE10_11 Geochemistry, crystal chemistry, isotope geochemistry, thermodynamics

      PE10_12 Sedimentology, soil science, palaeontology, earth evolution

      Preface

       Gwenn PERON-PINVIDIC1,2

       1 Geological Survey of Norway (NGU), Trondheim, Norway

       2 Department of Geoscience and Petroleum, Norwegian University of Science and Technology, Trondheim, Norway

      Continental margins mark the transition between continents and oceans, which are the two first-order types of land masses on Earth. Active continental margins are associated with convergent lithospheric plates where collisional processes occur – they are the sites of intense tectonic, seismic and volcanic activity; while passive continental margins correspond to the regions that mark the rupture of a continent and the opening of an ocean basin, ultimately leading to the establishment of an oceanic ridge. Passive margins archive two of the most fundamental geological processes operating on Earth: “rifting” and “breakup”. Passive continental margins, also often referred to as “rifted margins”, register the extension and ultimate separation of the continental lithosphere and the beginning of oceanic crust accretion. After continental breakup, they are tectonically quieter than the active margins.

Rifted margins contribute to our understanding of extensional processes in the continental lithosphere in several ways. First, they represent the most widespread manifestation of Mesozoic and Cenozoic extensional deformation, archiving the structures created during the dismembering of the supercontinent Pangea, a major stage in the tectonic history of our planet. In addition, they border almost all of the land masses that surround the Atlantic, Indian, Antarctic and Arctic Oceans and represent significant surfaces of today’s Earth. Moreover, since they represent the final stage of evolution of an intracontinental rift zone, they can provide a complete record of extensional history and are therefore unique geological features.

      Rifted margins are studied by various disciplines of Earth Science (geology, geophysics, geochemistry). Thanks to an increasing amount and better public access to high-quality data, there has been a great improvement in our understanding over the last two decades. However, there are still important debates happening in the scientific community on several questions. Their structural architecture, as well as their spatial and temporal evolution, are still being discussed. No strict consensus has been reached on the composition of the basement, tectonic structures, sedimentary geometries or magmatic content. Correspondingly, their relationship with the adjacent oceanic areas, specifically the first kilometers of oceanic crust, is still largely unconstrained.

Figure P.1. Topographic map of the world with the major ocean basins, rifted margins and main geological structures regularly mentioned in the literature and/or in this book

       How to use this book

This book focuses on continental rifted margins, with the aim of explaining the status of knowledge and the way in which understanding has evolved over the last few decades, thanks to the scientific community. Concise text descriptions are used throughout to ensure the content is practical and accessible. We have also incorporated myriad schemas and illustrative figures in all chapters in order to reach a wide audience, particularly students. For further detailed information, the reader is referred to key publications listed under the Further reading sections.

      The book is designed to be a useful tool for students and those who are new to the rifted margin community – a sort of “cookbook” to facilitate the reading of scientific publications and provide basic definitions and explanations on a series of key scientific questions. No detailed information is given on the methods: only succinct