ffirs.fm Page iii Wednesday, March 23, 2005 3:28 AM International Library of Archaeology Quaternary Dating Methods MIKE WALKER Department of Archaeology and Anthropology University of Wales, Lampeter, UK http://www.historiayarqueologia.com/group/library ffirs.fm Page ii Wednesday, March 23, 2005 3:28 AM International Library of Archaeology http://www.historiayarqueologia.com/group/library ffirs.fm Page i Wednesday, March 23, 2005 3:28 AM International Library of Archaeology Quaternary Dating Methods http://www.historiayarqueologia.com/group/library ffirs.fm Page ii Wednesday, March 23, 2005 3:28 AM International Library of Archaeology http://www.historiayarqueologia.com/group/library ffirs.fm Page iii Wednesday, March 23, 2005 3:28 AM International Library of Archaeology Quaternary Dating Methods MIKE WALKER Department of Archaeology and Anthropology University of Wales, Lampeter, UK http://www.historiayarqueologia.com/group/library ffirs.fm Page iv Wednesday, March 23, 2005 3:28 AM International Library of Archaeology Copyright © 2005 John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England Telephone (+44) 1243 779777 Email (for orders and customer service enquiries): [email protected] Visit our Home Page on www.wiley.com All Rights Reserved. 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Library of Congress Cataloging in Publication Data Walker, M.J.C. (Mike J.C.), 1947– Quaternary dating methods/Mike Walker. p. cm. Includes bibliographical references and index. ISBN 0-470-86926-7 (hb:acid-free paper) — ISBN 0-470-86927-5 (pbk.:acid-free paper) 1. Geochronometry. 2. Geology, Stratigraphic—Quaternary. 3. Radioactive dating. I. Title. QE508.W348 2005 551.7′01—dc22 2004029171 British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN-13 978-0-470-86926-0 (HB) 978-0-470-86927-7 (PB) ISBN-10 0-470-86926-7 (HB) 0-470-86927-5 (PB) Typeset in 10/12pt Times by Integra Software Services Pvt. Ltd, Pondicherry, India Printed and bound in Great Britain by Antony Rowe Ltd, Chippenham, Wiltshire This book is printed on acid-free paper responsibly manufactured from sustainable forestry in which at least two trees are planted for each one used for paper production. http://www.historiayarqueologia.com/group/library ffirs.fm Page v Wednesday, March 23, 2005 3:28 AM International Library of Archaeology For John Lowe http://www.historiayarqueologia.com/group/library ffirs.fm Page vi Wednesday, March 23, 2005 3:28 AM International Library of Archaeology http://www.historiayarqueologia.com/group/library ftoc.fm Page vii Wednesday, March 23, 2005 3:28 AM International Library of Archaeology Contents Preface xv 1 Dating Methods and the Quaternary 1 1.1 Introduction 1 1.2 The Development of Quaternary Dating 2 1.3 Precision and Accuracy in Dating 5 1.4 Atomic Structure, Radioactivity and Radiometric Dating 7 1.5 The Quaternary: Stratigraphic Framework and Terminology 9 1.6 The Scope and Content of the Book 12 Notes 15 2 Radiometric Dating 1: Radiocarbon Dating 17 2.1 Introduction 17 2.2 Basic Principles 18 2.3 Radiocarbon Measurement 19 2.3.1 Beta Counting 20 2.3.2 Accelerator Mass Spectrometry 20 2.3.3 Extending the Radiocarbon Timescale 23 2.3.4 Laboratory Intercomparisons 24 2.4 Sources of Error in Radiocarbon Dating 24 2.4.1 Contamination 24 2.4.2 Isotopic Fractionation 25 2.4.3 Marine Reservoir Effects 26 2.4.4 Long-Term Variations in 14C Production 27 2.5 Some Problematic Dating Materials 29 2.5.1 Lake Sediments 29 2.5.2 Shell 30 2.5.3 Bone 31 2.5.4 Soil 31 2.6 Calibration of the Radiocarbon Timescale 32 2.6.1 Dendrochronological Calibration 32 2.6.2 The INTCAL Calibration 32 2.6.3 Extending the Radiocarbon Calibration Curve 34 http://www.historiayarqueologia.com/group/library ftoc.fm Page viii Wednesday, March 23, 2005 3:28 AM International Library of Archaeology viii Contents 2.6.4 Bayesian Analysis and Radiocarbon Calibration 35 2.6.5 Wiggle-Match Dating 37 2.7 Applications of Radiocarbon Dating 37 2.7.1 Radiocarbon Dating: Some Routine Applications 37 2.7.1.1 Dating of plant macrofossils: Lateglacial cereal cultivation in the valley of the Euphrates 38 2.7.1.2 Dating of charcoal: a Holocene palaeoenvironmental record from western Germany 38 2.7.1.3 Dating of peat: a Holocene palaeoclimatic record from northern England 41 2.7.1.4 Dating of organic lake mud: a multi-proxy palaeoenvironmental record from Lake Rutundu, East Africa 41 2.7.1.5 Dating of marine micropalaeontological records: an example of a problem from the North Atlantic 43 2.7.1.6 Dating of marine shell: a Holocene aeolianite from Mexico 45 2.7.1.7 Dating of bone: the earliest humans in the Americas 47 2.7.2 Radiocarbon Dating of Other Materials 47 2.7.2.1 Dating of textiles: the ‘Shroud of Turin’ 48 2.7.2.2 Dating of old documents: the Vinland Map 49 2.7.2.3 Dating of lime mortar: medieval churches in Finland 51 2.7.2.4 Dating of hair: radiocarbon dates and DNA from individual animal hairs 51 2.7.2.5 Dating of iron artefacts: the Himeji nail and the Damascus sword 52 2.7.2.6 Dating of pottery: the earliest pottery in Japan 52 2.7.2.7 Dating of rock art: Palaeolithic cave paintings in Spain and France 53 Notes 54 3 Radiometric Dating 2: Dating Using Long-Lived and Short-Lived Radioactive Isotopes 57 3.1 Introduction 57 3.2 Argon-Isotope Dating 58 3.2.1 Principles of Potassium–Argon Dating 58 3.2.2 Principles of Argon–Argon Dating 59 3.2.3 Some Assumptions and Problems Associated with Potassium–Argon and Argon–Argon Dating 59 3.2.4 Some Applications of Potassium–Argon and Argon–Argon Dating 61 3.2.4.1 Potassium–argon and argon–argon dating of the dispersal of Early Pleistocene hominids 62 3.2.4.2 40Ar/39Ar dating of anatomically modern Homo sapiens from Ethiopia 62 http://www.historiayarqueologia.com/group/library