This page intentionally left blank Meteorites, Ice, and Antarctica Bill Cassidy led meteorite recovery expeditions in the Antarctic for 15 years. His searches resulted in the collection of thousands of meteorite specimens from the ice. This fascinating story is a first hand account of his field experiences on the US Antarctic Search for Meteorites Project, which he carried out as part of an international team of scientists. Cassidy describes this hugely successful field program in Antarctica and its influence on our understanding of the moon, Mars and the asteroid belt. He describes the hardships and dangers of fieldwork in a hostile environment, as well as the appreciation he developed for the beauty of the place. In the final chapters he speculates on the results of the trips and the future research to which they might lead. bill cassidy was the founder of the US Antarctic Search for Meteorites project (ANSMET). He received the Antarctic Service Medal of the United States in 1979, in recognition of his successful field work on the continent. His name is found attached to a mineral (cassidyite), on the map of Antarctica (Cassidy Glacier) and in the Catalogue of Asteroids (3382 Cassidy). He is currently Emeritus Professor of Geology and Planetary Science at the University of Pittsburgh. Frontispiece: The illustration shows a digitally enhanced, false-color mosaic of satellite photos of the Allan Hills – Elephant Moraine area. Blue areas are patches of exposed ice. Notice that the Allan Hills Main Icefield stands away from the roughly Y-shaped Allan Hills exposure, due to the presence of a low-lying structural barrier (a subice ridge). Ice flows over this barrier toward Allan Hills. Elephant Moraine is also indicated. The regional linear patches of blue ice, in one of which are found Elephant Moraine and Reckling Moraine, mark the presence of a subice ridge. Ice is spilling over this ridge on its journey northward. The irregular dark area at the top of the photo is open water of the Ross Sea, which is completely frozen during most of the year. Contorted patterns in the water are aggregates of floating ice chunks whose trends reflect eddy currents. Brownish patches in the upper right quadrant are Dry Valleys. (Courtesy of Baerbel Luchitta, USGS Image Processing Facility, Flagstaff, Arizona, USA) Meteorites, Ice, and Antarctica william a. cassidy University of Pittsburgh    Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo Cambridge University Press The Edinburgh Building, Cambridge  , United Kingdom Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521258722 © Cambridge University Press 2003 This book is in copyright. Subject to statutory exception and to the provision of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published in print format 2003 - ---- eBook (EBL) - --- eBook (EBL) - ---- hardback - --- hardback Cambridge University Press has no responsibility for the persistence or accuracy of s for external or third-party internet websites referred to in this book, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate. I dedicate this book to my wife,Bev,who ran our home,and our family,for fifteen field seasons while I was in Antarctica,and never once complained. Contents Foreword page ix Acknowledgments xiii Introduction 1 PART I Setting the stage 1 Antarctica and the National Science Foundation 7 2 How the project began 16 3 The first three years 32 4 The beat goes on: later years of the ANSMET program 57 5 Alone (or in small groups) 84 PART II ANSMET pays off: field results and their consequences 6 Mars on the ice 103 7 Meteorites from the moon 144 8 How, and where, in the solar system . . .? 186 viii contents PART III Has it been worthwhile? 9 Evaluating the collection – and speculating on its significance 227 10 Meteorite stranding surfaces and the ice sheet 274 11 The future: what is, is, but what could be, might not 320 Appendices A The US–Japan agreement 335 B ANSMET field participants, 1976–1994 337 Index of people 342 Index of Antarctic geographic names 344 Subject index 346