I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Ore Geology and Industrial Minerals An Introduction GEOSCIENCE TEXTS SERIES EDITOR A. HALLAM LapworthProfessorofGeology UniversityofBirmingham EngineeringGeology F.C. BEAVIS OreGeologyand Industrial Minerals: An Introduction A.M. EVANS An Introductionto GeophysicalExploration P. KEAREY AND M. BROOKS Principles ofMineral Behaviour A. PUTNIS AND J.D.C. MCCONNELL TheContinentalCrust S.R. TAYLOR AND S.M. MCLENNAN SedimentaryPetrology: an Introduction M.E. TUCKER GEOSCIENCE TEXTS Ore Geology and Industrial Minerals An Introduction ANTHONY M. EVANS BSc, PhD,MIMM,FGS FonnerlySeniorLecturerin MiningGeology UniversityofLeicester THIRD EDITION A ~ II Blackwell ~ Publishing ©1980,1987,1993byBlackwellScienceLtd aBlackwellPublishingcompany BLACKWELLPUBLISHING 350MainStreet,Malden,MA02148-5020,USA 9600GarsingtonRoad,OxfordOX42DQUK 550SwanstonStreet,Carlton,Victoria3053,Australia TherightoftheAuthortobeidentifiedastheAuthorofthisWorkhasbeenassertedin accordancewiththeUKCopyright,Designs,andPatentsAct1988. Allrightsreserved.Nopartofthispublicationmaybereproduced,storedinaretrievalsystem, ortransmitted,inanyformorbyanymeans,electronic,mechanical,photocopying,recordingor otherwise,exceptaspermittedbytheUKCopyright,Designs,andPatentsAct1988,\vithoutthe priorpermissionofthepublisher. Firstpublished1980underthetitleAnIntroduction toOreGeology Chineseedition1985 Secondedition1987 Germanedition1992 Malaysianedition1989 Japaneseedition1989 Thirdedition1993 15 2009 LibraryofCongressCalaloging-in-PulJlicationData Evans,AnthonyM. Oregeologyandindustrialminerals/AnthonyM.Evans,-3rded. p. em.- (Geosciencetexts) Rev.ed.of:AnIntroductiontooregeology,2nded.1987. Includesindex. ISBN978-0-632-02953-2 1.Oredeposits. 2.Industrialminerals. 1.Evans,AnthonyM. Introductiontooregeology. II.Title III.Series. QE390.E92 1993 553'.1-<:Ic20 AcataloguerecordforthistitleisavailablefromtheBritishLibrary. SetbySemantieGraphics,Singapore Printedandbound inSingapore byC.OSPrintersPteLtd Thepublisher'spolicyistousepennanentpaperfrom millsthatoperateasustainableforestry policy,andwhichhasbeenmanufacturedfrompulpprocessedusingacid-freeandelementary chlorine-freepracticf's Furthermore,thepublisherensuresthatthetextpaperandcoverboard usedhavemetacceptableenvironmentalaccreditationstandards. Forfurtherinformationon BlackwellPublishing,visitourwebsite: www.blackwe1lpublishing.com Contents Prefaceto the third edition, vii 12 Greisen deposits, 154 Preface to the second edition, viii 13 The skarn environment, 157 Preface to the first edition, ix 14 Disseminated and stockwork deposits associated with plutonic intrusives, 171 Unitsand abbreviations, x 15 Stratiform sulphide, oxideandsulphate deposits ofsedimentaryand volcanic Part 1: Principles environments, 190 Some elementary aspects ofmineral 16 The veinassociation and someother economics, 3 hydrothermal deposit types, 213 2 The nature and morphologyofthe principal 17 Strata-bound deposits, 233 types ofore deposit, 26 18 Sedimentary deposits, 244 3 Texturesand structures ofore andgangue minerals. Fluid inclusions. Wall rock 19 Residual deposits and supergene enrichment, alteration, 40 262 4 Some major theories oforegenesis, 52 20 Industrial minerals, 272 5 Geothermometry,geobarometry, paragenetic 21 Short notes on selected industrial minerals, sequence, zoning and dating oforedeposits, 301 84 22 The metamorphism ofore deposits, 305 Part 2: Examples ofthe more importanttypes Part 3: Mineralization in space and time ofore deposit 23 The global distribution ofore deposits: 6 Classificationofore deposits, 99 metallogenic provinces and epochs, plate 7 Diamond deposits in kimberlites and tectoniccontrols, 313 lamproites, 104 24 Ore mineralization through geological time, 8 The carbonatite-alkaline igneous ore 339 environment, 114 Appendix, 345 9 The pegmatitie environment, 121 10 Orthomagmatic deposits ofchromium, References, 347 platinum, titanium and iron associated with basicand ultrabasic rocks, 128 Index, 379 II Orthomagmaticcopper-nickel-iron (-platinoid) deposits associated with basic and ultrabasic rocks, 139 v I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Preface to the third edition This edition, like the second, is an enlarged and In turning my hand to writing about industrial extensively revised work. I blame much of the minerals I have been ablyassisted and encouraged increased size, after all this is an introductory text by Professor Peter Scott of Camborne School of only, on many ofmy readers, reviewers and trans Mines in Cornwall, and Professor Ansel Dunham lators. These, almost without exception, have ig andMrMichaelWhateleyofLeicesterUniversity's nored the plea at the end ofthe preface to my first Geology Department. Mr David Highley of the edition and have called for additions, changes but British Geological Survey also gave me invaluable rarelyfordeletions!OnceagainIamintheirdebtfor help, particularlyinthe sphereofmineralstatistics. approving letters, good reviews and their many Without the help of these good friends this text helpful comments. I am particularlygrateful to the would contain many more sinsofcommission and manylecturers in North Americaand the UKwho omissionthanarenodoubtstillpresent.Manyofmy returned my questionnaire concerning industrial other colleagues at Leicester have good naturedly minerals. Theserespondents votedoverwhelmingly allowed me to pester them with questions in my fortheinclusionofsectionsonthistopicandforthe search for enlightenment on various, to me, dark mode of presentation that I had tentatively sug problems. I would also like to thank all those in gested. Of this group I would like, to give sincere industrial circles who have encouraged me to pro thanks toDrBladhofWittenberg University,Ohio ceedtoathirdedition,inparticularProfessorColin andDrGarlickofHumboldtUniversity,California Bristow who supplied me with invaluable data, for theconsiderablethoughtand time they putinto which I have incorporated intoChapter 1. their replies. Apart from the new material discussed above I All this encouragement has led me to develop haveincludedadescriptionofhydraulicfracturing, Chapter 1into an overview ofmineral economics, hypothermal and epithermal gold mineralization to emphasize the non-metallurgical applications of and introduced new material into most chapters of metallicelementsatvariouspointsinthebookandto this book. This work is, however, an introductory include two chapters devoted entirely to industrial text and therefore does not deal with the esoteric minerals. The first ofthese (Chapter 20) illustrates subjects, lists of which one or two reviewers have in alittledepth somechosenexamplesofindustrial drawn up and then proceeded to deplore their minerals(and bulkmaterials) that possesscontrast absence. Thisgameis betterplayed inassessingthe ingchemicalandphysicalpropertiesaswellashaving merits ofadvancedgeology texts! different modes of formation, uses and financial Finally I am happy once more to confess my values. The second chapter (Chapter 21) contains overwhelming debt to my loving wife who has summary details of other industrial mineral com encouraged and helped me at every stage in the modities to make the readeraware ofthe potential preparationofthisthird edition, especiallythrough ofmanycommonnon-metalliferous resources. the hiatus ofmajor surgery. Anthony Evans Burton on the Wolds January 1992 vii Preface to the second edition Thisrevisionappearsinresponsetowhatthemedia posits.Thechapteronoregenesishasbeenenlarged arepleasedtocall populardemand. The publishers and I am grateful to Dr A.D. Saunders for his and Iwerequiteastonished by the impressivesales comments on it. figuresforthefirstedition,theflatteringreviews,the To emphasize still further the importance of 'fan mail' from places as far apart as France, viewing mineral deposits from an economic stand California, Japan, New Zealand and Spainandthe point, IhaveexpandedChapter I considerablyand offerstotranslateitintoboth FrenehandJapanese. Iam gratefulto MrM.K.G. Whateleyfor reviewing I would like to express my thanks to the many it. Ihavecontinued mypolicyofthefirst edition of readerswhohavebeenkindenoughtocommenton peppering the text with grade and tonnage figures the first edition, instead ofmakingthe usual excla and other allusions to mineral economics in a mation marks in the margins oftheir copies when further attempt to create commercial awareness in theyobjectedtomyprose,orcaughtmeoutinsome the tyro. fact, or disagreed with my interpretation of the As in the first edition bibliographic references evidence. Many of what I hope will be seen as generally direct attention to works in English. The improvementsto the text owe their presenceto the studentshouldnotethatthis, initself,ismisleading; kindness ofreaders and reviewers, and I hope that for much significant work in the field is written in noneofthem will feel that any oftheirconstructive French, German, Russian and otherlanguages. But criticism has been ignored. works in English are much more widely accessible I have attempted a thorough revision and many and the main aim has been to help the reader find sections have been rewritten. A chapter on dia worksthatwillamplifythediscussionsthisbookhas monds has been added to meet requests. Chapters begun. on greisen and pegmatite deposits have also been Muchofthesuccessofthefirsteditionwasdue to added, the former in response to the changing SueAldridge'sfineartworkandIamdeeplygrateful situationintin miningfollowingtherecenttincrisis to her for the pains she has taken. Once again I and the latter in response to suggestions from lovingly acknowledge the encouragement, editorial geologists in a numberofoverseas countries. Some andtypingskillswhichmywifehascontributedand chaptershavebeenconsiderablyexpandedand new without which this edition would still be awaiting sections added; in particular on disseminated gold attention. deposits and unconformity-associated uranium de- Anthony Evans Burton on the Wolds July 1986 viii