EARTH AS AN EVOLVING PLANETARY SYSTEM This Page Intentionally Left Blank Earth as an Evolving Planetary System Kent C. Condie AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Academic Press is an imprint of Elsevier Elsevier Academic Press 200 Wheeler Road, Burlington, MA 01803, USA 525 B Street, Suite 1900, San Diego, CA 92101-4495, USA 84 Theobald’s Road, London WC1X 8RR, UK This book is printed on acid-free paper Copyright © 2005, Elsevier Inc. All rights reserved. Cover image courtesy of Tasa Graphic Arts, Inc., Taos, NM http://www.tasagraphicarts.com No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone: (+44) 1865 843830, fax: (+44) 1865 853333, e-mail:
[email protected] You may also complete your request on-line via the Elsevier homepage (http://elsevier.com), by selecting “Customer Support” and then “Obtaining Permissions.” Library of Congress: Application submitted British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN: 0-12-088392-9 For information on all Academic Press publications visit our Web site at www.books.elsevier.com Printed in the United States of America 04 05 06 07 08 09 9 8 7 6 5 4 3 2 1 Preface Although this book began life in 1976 with the title Plate Tectonics and Crustal Evolution, the subject matter has gradually changed focus with subsequent editions, and especially since the third edition in 1989. In the last decade it has become increasingly clear that the various components of Earth act as a single, interrelated system, often referred to as the Earth System. One reviewer of the fourth edition pointed out that the title of the book was no longer appropriate, since plate tectonics was not a major focus. This is even more so in this fifth version, and thus, I introduce a new title for the book: Earth as an Evolving Planetary System. Since the first edition in 1976, which appeared on the tail end of the plate tectonics revolution of the 1960s, our scientific database has grown exponentially and continues to grow—in fact, much faster than we can interpret it. If one compares the earlier editions of the book with this edition, a clear trend is apparent. Plate tectonics is now assimilated into geological textbooks and is part of the vernacular. The changing emphasis over the last 30 years is from how one system in our planet works (plate tectonics) to how all systems in our planet work, how they are related, and how they have governed the evolution of the planet. As scientists continue to work together and share information from many disciplines, this trend should continue for many years into the future. Today, more than at any time in the past, we are beginning to appreciate the fact that to understand the history of our planet requires understanding the various interacting components and how they have changed with time. Although science is made up of specialties, to learn more about how Earth operates requires input from all of these specialties—geology alone is not sufficient. In this new book the various subsystems of the Earth are considered as vital components in the evolution of our planet. Subsystems include such components as the crust, mantle, core, atmosphere, oceans, and life. As with previous editions, the book is written for advanced undergraduate and graduate students and assumes a ba