Geologia Estructural

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STRUCTURAL GEOLOGY
An Introduction to Geometrical Techniques fourth edition

Many textbooks describe information and theories about the Earth without training students to utilize real data to answer basic geological questions. This volume – a combination of text and lab book – presents an entirely different approach to structural geology. Designed forundergraduate laboratory classes, it is dedicated to helping students solve many of the geometrical problems that arise from field observations. The basic approach is to supply step-by-step instructions to guide students through the methods, which include well-established techniques as well as more cutting-edge approaches. Particular emphasis is given to graphical methods and visualizationtechniques, intended to support students in tackling traditionally challenging two- and three-dimensional problems. Exercises at the end of each chapter provide students with practice in using the techniques, and demonstrate how observations and measurements from the field can be converted into useful information about geological structures and the processes responsible for creating them. Building on thesuccess of previous editions, this fourth edition has been brought fully up-to-date and incorporates new material on stress, deformation, strain and flow. Also new to this edition are a chapter on the underlying mathematics and discussions of uncertainties associated with particular types of measurement. With stereonet plots and full solutions to the exercises available online atwww.cambridge.org/ragan, this book is a key resource for undergraduate students as well as more advanced students and researchers wanting to improve their practical skills in structural geology. D o n R a g a n was educated at Occidental College, University of Southern California and at the University of Washington in Seattle, receiving his Ph.D. in 1960. He spent a year as a Fulbright Scholar at the University ofInnsbruck, and later, with a National Science Foundation Fellowship, at Imperial College, London, where he received a Diploma of Membership in Geology (DIC). His teaching career at the University of Alaska, Fairbanks, and at Arizona State University has spanned a total of 34 years, and has focused on imbuing students with a thorough understanding of geometrical and analytical techniques in structuralgeology. His research interests center on the role of structural settings in structure-making processes, including studies of Alpine peridotites, glacial ice and welded tuffs.

STRUCTURAL GEOLOGY
An Introduction to Geometrical Techniques
fourth edition

donal m. ragan
Arizona State University, USA

CAMBRIDGE UNIVERSITY PRESS

Cambridge, New York, Melbourne, Madrid, Cape Town,Singapore, São Paulo, Delhi, Dubai, Tokyo Cambridge University Press The Edinburgh Building, Cambridge CB2 8RU, UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521897587 © D. M. Ragan 2009 This publication is in copyright. Subject to statutory exception and to the provision of relevant collectivelicensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published in print format 2009 ISBN-13 ISBN-13 ISBN-13 978-0-511-64137-4 978-0-521-89758-7 978-0-521-74583-3 eBook (NetLibrary) Hardback Paperback

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For ´ Janne, Anneliese and Asta

Contents

Preface Acknowledgements 1 Structural planes 1.1 Introduction 1.2 Definitions 1.3 Dip and strike 1.4 Accuracy of angle measurements 1.5 Graphic methods 1.6 Finding apparent dip 1.7 Analytical...