Introduction to Mineral Exploration Second Edition Edited by Charles J. Moon, Michael K.G. Whateley & Anthony M. Evans With contributions from William L. Barrett Timothy Bell Anthony M. Evans John Milsom Charles J. Moon Barry C. Scott Michael K.G. Whateley introduction to mineral exploration Introduction to Mineral Exploration Second Edition Edited by Charles J. Moon, Michael K.G. Whateley & Anthony M. Evans With contributions from William L. Barrett Timothy Bell Anthony M. Evans John Milsom Charles J. Moon Barry C. Scott Michael K.G. Whateley Copyright © 2006 by Charles J. Moon, Michael K.G. Whateley, and Anthony M. Evans BLACKWELL PUBLISHING 350 Main Street, Malden, MA 02148-5020, USA 9600 Garsington Road, Oxford OX4 2DQ, UK 550 Swanston Street, Carlton, Victoria 3053, Australia The rights of Charles J. Moon, Michael K.G. Whateley, and Anthony M. Evans to be identified as the Authors of this Work have been asserted in accordance with the UK Copyright, Designs, and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs, and Patents Act 1988, without the prior permission of the publisher. First edition published 1995 by Blackwell Publishing Ltd Second edition published 2006 1 2006 Library of Congress Cataloging-in-Publication Data Introduction to mineral exploration.–2nd ed. / edited by Charles J. Moon, Michael K.G. Whateley & Anthony M. Evans; with contributions from William L. Barrett . [et al.]. p. cm. Evans’s appears first on the previous ed. Includes bibliographical references and index. ISBN-13: 978-1-4051-1317-5 (pbk. : acid-free paper) ISBN-10: 1-4051-1317-0 (pbk. : acid-free paper) 1. Prospecting. 2. Mining geology. I. Moon, Charles J. II. Whateley, M.K.G. III. Evans, Anthony M. TN270.I66 2006 622′.1—dc22 2005014825 A catalogue record for this title is available from the British Library. Set in 9/11pt Trump Mediaeval by Graphicraft Limited, Hong Kong Printed and bound in India by Replika Press PVT Ltd The publisher’s policy is to use permanent paper from mills that operate a sustainable forestry policy, and which has been manufactured from pulp processed using acid-free and elementary chlorine-free practices. Furthermore, the publisher ensures that the text paper and cover board used have met acceptable environmental accreditation standards. For further information on Blackwell Publishing, visit our website: www.blackwellpublishing.com Contents Contributors ix Preface to the Second Edition xi Preface to the First Edition xii Units, Abbreviations, and Terminology xiii Part I – Principles 1 1 Ore, Mineral Economics, and Mineral Exploration 3 Charles J. Moon and Anthony M. Evans 1.1 Introduction 3 1.2 Mineral economics 3 1.3 Important factors in the economic recovery of minerals 11 1.4 Structure of the mining industry 12 1.5 Some factors governing the choice of exploration areas 13 1.6 Rationale of mineral exploration 14 1.7 Further reading 18 2 The Mineralogy of Economic Deposits 19 Anthony M. Evans 2.1 Introduction 19 2.2 Mineralogical investigations 25 2.3 Further reading 32 3 Mineral Deposit Geology and Models 33 Anthony M. Evans and Charles J. Moon 3.1 Nature and morphology of orebodies 33 3.2 Wall rock alteration 39 3.3 Geological models of mineral deposits 40 3.4 Further reading 45 3.5 Summary of Chapters 1, 2, and 3 46 3.6 Appendix: mineral deposit model classification of Cox and Singer (1986) 46 4 Reconnaissance Exploration 52 Charles J. Moon and Michael K.G. Whateley 4.1 Exploration planning 53 4.2 Desk studies and reconnaissance 57 vi CONTENTS 4.3 Sustainable development 67 4.4 Summary 69 4.5 Further reading 69 5 From Prospect to Prefeasibility 70 Charles J. Moon and Michael K.G. Whateley 5.1 Finding a drilling target 70 5.2 When to drill and when to stop 84 5.3 Recycling prospects 93 5.4 The Bre-X Minerals saga 100 5.5 Summary 102 5.6 Further reading 102 6 Remote Sensing 104 Michael K.G. Whateley 6.1 Introduction 104 6.2 The Landsat System 105 6.3 Other imaging systems 116 6.4 Photogeology 117 6.5 Summary 125 6.6 Further reading 126 7 Geophysical Methods 127 John Milsom 7.1 Introduction 127 7.2 Airborne surveys 127 7.3 Magnetic surveys 130 7.4 Gravity method 133 7.5 Radiometrics 135 7.6 Resistivity 136 7.7 Spontaneous polarization (SP) 138 7.8 Induced polarization (IP) 138 7.9 Continuous-wave electromagnetics 142 7.10 Transient electromagnetics (TEM) 144 7.11 Remote source methods (VLF and magnetotellurics) 145 7.12 Seismic methods 147 7.13 Ground radar 148 7.14 Borehole geophysics 149 7.15 Geophysics in exploration programs 150 7.16 Integration of geological and geophysical data 150 7.17 The role of the geologist in geophysical exploration 151 7.18 Dealing with contractors 152 7.19 Further reading 153 8 Exploration Geochemistry 155 Charles J. Moon 8.1 Planning 155 8.2 Analysis 159 8.3 Interpretation 162 8.4 Reconnaissance techniques 164 8.5 Follow-up sampling 177 CONTENTS vii 8.6 Summary 178 8.7 Further reading 178 9 Mineral Exploration Data 179 Charles J. Moon and Michael K.G. Whateley 9.1 Data capture and storage 179 9.2 Data integration and geographical information systems 186 9.3 Integration with resource calculation and mine planning software 197 9.4 Further reading 198 10 Evaluation Techniques 199 Michael K.G. Whateley and Barry C.Scott 10.1 Sampling 199 10.2 Pitting and trenching 218 10.3 Drilling 218 10.4 Mineral resource and ore reserve estimation, grade calculations 230 10.5 Geotechnical data 243 10.6 Summary 249 10.7 Further reading 250 10.8 Appendix: use of Gy’s sampling formula 250 11 Project Evaluation 253 Barry C.Scott and Michael K.G. Whateley 11.1 Introduction 253 11.2 Value of mineralisation 253 11.3 Cash flow 260 11.4 Study definitions 262 11.5 Mineral project valuation and selection criteria 265 11.6 Risk 270 11.7 Inflation 271 11.8 Mineral project finance 272 11.9 Summary 276 11.10 Further reading 276 Part II – Case Studies 279 12 Cliffe Hill Quarry, Leicestershire – Development of Aggregate Reserves 281 Michael K.G. Whateley and William L. Barrett 12.1 Introduction 281 12.2 Phase 1 – order-of-magnitude study 282 12.3 Phase 2 – pre-feasibility study 283 12.4 Phase 3 – feasibility study 284 12.5 Phase 4 – detailed engineering 291 12.6 Quarrying and environmental impact 292 12.7 Summary 293 13 Soma Lignite Basin, Turkey 294 Michael K.G. Whateley 13.1 Introduction 294 13.2 Exploration programs 295 viii CONTENTS 13.3 Geology 298 13.4 Data assessment 303 13.5 Geotechnical investigation 307 13.6 Lignite quality 309 13.7 Lignite reserve estimates 314 13.8 Surface mine evaluation 315 13.9 Summary 319 13.10 Further reading 319 14 Witwatersrand Conglomerate Gold – West Rand 320 Charles J. Moon and Michael K.G. Whateley 14.1 Introduction 320 14.2 Geology 320 14.3 Economic background 330 14.4 Exploration models 333 14.5 Exploration methods 334 14.6 Reserve estimation 344 14.7 Exploration and development of the southern part of the West Rand Goldfield 345 14.8 Conclusions 357 15 A Volcanic-associated Massive Sulfide Deposit – Kidd Creek, Ontario 358 Anthony M. Evans and Charles J. Moon 15.1 Introduction 358 15.2 Volcanic-associated massive sulfide deposits 358 15.3 The Kidd Creek Mine 370 15.4 Conclusions 381 16 Disseminated Precious Metals – Trinity Mine, Nevada 382 Michael K.G. Whateley, Timothy Bell and Charles J. Moon 16.1 Background 382 16.2 Trinity Mine, Nevada 386 16.3 Exploration 387 16.4 The geology of Pershing County and the Trinity District 391 16.5 Development and mining 395 16.6 Mineral processing 397 16.7 Environmental considerations 397 16.8 Grade estimation 399 16.9 Ore reserve estimation 409 16.10 Summary and conclusions 412 17 Diamond Exploration – Ekati and Diavik Mines, Canada 413 Charles J. Moon 17.1 World diamond deposits and exploration 413 17.2 Canadian discoveries: Ekati and Diavik 431 17.3 Summary 443 Internet Links 444 References 447 Index 469 Contributors WILLIAM L. BARRETT Tarmac Quarry Products Ltd, Millfields Road, Ettingshall, Wolverhamp- ton WV4 6JP. Previously Geological Manager, Estates and Environment Department of Tarmac (now Consultant) but he has enjoyed a varied career in applied geology. His first degree was taken at the University of Wales and he obtained his doctorate from Leeds University. Much of his early career was spent in base metal exploration and underground mining in East Africa and this cul- minated with a spell as Chief Geologist at Kilembe Mines. Latterly he has been concerned with all aspects of Tarmac’s work in the field of industrial minerals. TIMOTHY BELL Bell Hanson, Foss Road, Bingham NG11 7EP. Graduated from West London Col- lege with a first class degree (cum laude) in Geology and Geography before obtaining an MSc degree with distinction in Mineral Exploration and Mining Geology at Leicester University in 1989. He joined CP Holdings (opencast coal contractors) as geologist in charge of computer applications in the mining division before moving to SURPAC Software International where he was Technical Manager in their Nottingham office and is now running his own business. ANTHONY M. EVANS 19 Hall Drive, Burton on the Wolds, Loughborough LE12 5AD.