Goldfarb, Richard J.

English

University of New Brunswick: Centre for Digital Scholarship Journals

46painstaking elucidation of  the charac-teristics of, and relationships between,organisms. This work is unglamorous;sometimes, as Fortey remarks, it is dis-missed as “counting hairs on legs”. Yetit is fundamental to all biosciences,including palaeontology. New speciesare being discovered all the time andwe only know they are new by consult-ing the archive of  known anddescribed species. As Fortey pointsout, in some groups, such as beetlesand fungi, millions of  species remainto be described and named. Further,Fortey notes the urgency of  this task;documenting the world’s biodiversity iscritical in the light of  increasing extinc-tion rates. Although the whole organ-ism is still the fundamental unit ofstudy, especially for elucidating struc-tures and behaviour, Fortey acknowl-edges the undoubted advances inmolecular studies in recent years, andtheir value in unravelling knotty taxo-nomic conundrums. He illustrates thiswith a compelling but complicatedexample from truffle taxonomy. Cladis-tics is discussed too. Lest one shouldthink of  taxonomy as sterile and irrele-vant, Fortey presents examples of  itspractical implications, includingresearch towards the eradication ofdiseases such as bilharzia, the controlof  harmful insect pests, and develop-ment of  more productive agriculturalcrops. The impacts of  this work can befar-reaching.Museums have not beenimmune to the upheavals and disloca-tions consequent upon social and eco-nomic changes in recent years. Forteydocuments their impact on the NHM,especially the imposition of  a businessmodel of  operation, and the resultingreorganization and staff  cuts. Thismodel often requires justification ofresearch in terms of  immediate bene-fits, which militates against the“research for its own sake” ethos.Fortey is clearly at odds with the newsystem; he presents several examples ofunanticipated benefits resulting fromcuratorial work that was driven solelyby scientific curiosity. Perhaps the mostsurprising is the discovery of  a lostMozart manuscript by a researcherlooking for illustrations of  herring.Fortey also describes the tensionsbetween the front of  house (exhibi-tions and public areas) and back ofhouse areas (collections and researchlabs) and the increasing staff  numbersbeing allocated to marketing and fundraising, rather than curatorial work andresearch. Galleries, exhibitions, andoutreach get limited discussion,although Fortey recognizes changingpublic expectations for museumsthrough the years. He touches onlybriefly on his experience in gallerydevelopment. Evidently, there is anoth-er book to be written about this aspectof  museum work, in which curatorsare often heavily involved. However,here the focus is firmly on the back ofhouse activities. Fortey notes, with per-haps a certain amount of  regret, theincreasing lack of  tolerance for eccen-tricity or, with less regret, for non-pro-ductivity. He also describes every cura-tor’s worst nightmare: rogues in themuseum, or people who gain positionsof  trust and then steal specimens.Thankfully, Fortey concentrates moreon the positive and contributoryaspects of  the passion for collections. I found myself  cheering,chuckling and smiling wryly at manyplaces in this book. It is hugely enter-taining. True, it could be classified as agentle polemic or as self-justification.Special pleading? Well, perhaps. Someof  the situations Fortey describes areparticular to museums. Yet his “tell itlike it is” account of  museum lifeincludes much that will be familiar toanyone who has ever worked in a simi-lar large institution or organization,such as a university or geological sur-vey. His discussion is wide-ranging,persuasive, thought provoking, andlucid. As a curator myself, I certainlyagree with Fortey that museums arespecial places. Now, thanks to Fortey’ssplendid portrayal, the pleasures andimplications of  museum work can bewidely shared. I highly recommend hisbook to my colleagues in geoscience.Gold Deposits of the CISGregory LevitanXlibris (2008)ISBN: 978-1-4363-5354-0ISBN: 978-1-4363-5353-3Price $29.99 (Hardback), $19.99 (Paper-back)Reviewed by Richard J. GoldfarbUnited States Geological SurveyBox 25046, Mail Stop 973Denver Federal CenterDenver, CO 80225, USA  E-mail: goldfarb@usgs.govGold Deposits of  the CIS (i.e. Common-wealth of  Independent States) providesa series of  brief  descriptions of  themajor gold deposits and resources ofthe former Soviet Union (FSU).  Thisregion of  Eurasia, extending from lati-tude 30EE (Ukraine) to 175EE (Kam-chatka), and as far south as latitude39EN (Tajikistan), is defined as con-taining the world’s largest cumulativegold reserve.  Although a few majordeposits such as Muruntau, Kumtor,and Sukhoi Log have recently receivedattention in the Western economicgeology literature, many of  the largegold systems in this region lack anyEnglish-language geological descriptionbeyond a few vague sentences on com-pany websites.  Thus, this bookattempts to fill a need in the basic oregeology literature.The author of  the volume,Gregory Levitan, is among the fewindividuals qualified to fill such a needin the economic geology field.  Heworked on mineral deposits for theSoviet Ministry of  Geology for 35years within the FSU, before moving tothe West and spending the most recentfifteen years as a consultant specializ-ing on gold ores within the same vastregion.  His most recent experience isreflected in the inclusion of  availablemining and mineral economics data ondescribed deposits, material commonlylacking in other published descriptionsof  gold deposits within the FSU.The book begins with twobrief  introductory chapters, one on thehistory of  exploration and mining, andthe second describing the complexclassification system of  gold depositsin the CIS.  The classification system isGEOSCIENCE CANADA Volume 36  Number 1 March 2009 47based on gold ore host rocks and isused to subdivide the remainder of  thebook.  Deposits are grouped into thoseassociated with Archean and Paleopro-terozoic host rocks (Chapter 3), andNeoproterozoic through Phanerozoicsedimentary, intrusive, and volcanichost rocks (Chapter 4).  Most westernreaders will recognize orogenic, intru-sion-related, skarn, and Carlin-typedeposits as being described within thefirst three groups of  host rocks, andthe epithermal deposit types as beingdiscussed within the volcanic rock-related section of  the book.  Thesefour groups of  gold deposits are fur-ther subdivided into sections withinchapters 3 and 4; these sections arebased on both, mineralization style andmajor mineralogical signatures of  theores.  The deposits discussed in thisbook are strictly those in which gold,or rarely silver, is the dominant orecomponent.  Hence, large auriferousporphyry copper deposits, such as thegiant Almalyk system in Uzbekistan,are not described.Chapters 3 and 4 are three- tofive-page-long descriptions of  51major gold deposits that occur in theFSU.  Each description typicallyincludes location coordinates, regionaland local geological descriptions, mapsand cross-sections of  variable quality,ore and alteration mineralogy, availablegrade and tonnage data, any publishedgeochronology, summary of  interestinggeochemical features, and the domi-nant genetic interpretation(s) on oreformation.  Chapter 3 summarizes theolder FSU gold deposits; these Pre-cambrian ores are basically the oro-genic gold deposits of  the UkrainianShield in the southwestern corner ofthe East European Platform.Chapter 4 discusses theremaning gold deposits and thus con-stitutes the bulk of  the book.  Thesedimentary rock-hosted deposits aredivided into those hosted by a) meta-morphic sequences, b) black shales andcarbonates, and c) sedimentary andcarbonate rocks.  The first of  thesegroups is characterized by limitedarsenic concentrations in pyrite, rela-tively high formation pressures andtemperatures, ‘greenstone’ (probablymeaning greenschist) facies metamor-phism, and thick flysch over maturecontinental crust, which would suggesta back-arc tectonic setting.  These oresin metamorphic sequences are furtherbroken down into ‘deposit types’ thatinclude gold–feldspar–carbonate–quartz (Kumtor), gold–quartz (Sovet-skoye), gold–feldspar–carbonate-sulfide(Muruntau), and gold–quartz ± car-bonate (Sukhoi Log).  At times, thenumerous levels of  classifications seemto become too complex and can becontradictory and confusing.  Forexample, in the section describing thegold–feldspar–carbonate–quartz typedeposits, a discussion of  Muruntau fol-lows that of  Kumtor and begins bystating Muruntau is another example ofgold–feldspar–carbonate-sulfide typemineralization.  What happened to the‘quartz’?  Furthermore, the Muruntaumineralization is said to reflect twostages of  hydrothermal activity, and tocontain five assemblages that are notrelated to these stages, although thefifth assemblage is actually called a‘stage’.  The second sedimentary rock-hosted group (black shales and carbon-ates) includes deposits such asOlimpiada, Bakirchok, and Daugyztau.Many features of  this group are notobviously different than the features ofthe first group; for example, host rocksare affected by greenschist metamor-phism, gold-bearing arsenopyrite ispresent, and formation temperaturesabove 400EC are reported for some ofthe largest deposits.  Yet some depositsin this group are lower temperatureand seem to resemble epizonal Sb-richorogenic gold deposits, such as theAlaskan Donlin Creek deposit.  Also,gold–mercury–quartz deposits in thisgroup have similarities with Carlinores; these include Kyuchus in easternRussia and perhaps Vorontsovka in theUrals.  If  I had to generalize, my opin-ion would be that this second groupincludes some of  the same mesozonalorogenic gold deposits that aregrouped within metamorphic sequencehost rocks, as well as epizonal orogenicand Carlin-type gold deposits.  Thethird group (sedimentary and carbon-ate rocks) is suggested to consist ofepithermal gold deposits in lowergreenschist facies rocks and distal toany known igneous rocks.  The silver-rich nature of  these deposits (e.g.Okzhetpes) and reported low-tempera-ture phases such as kaolinite and dick-ite, are used to support such an inter-pretation.The intrusion-related golddeposits described in Chapter 4 arealso divided into three subgroups: a)stockworks, veinlets, and dissemina-tions in plutons (e.g. Vasil’kovskoye,Jilau); b) veins within and near plutons(e.g. Jerooy, Natalka, Darasun,Kochkar, Berizovsk); and c) skarns (e.g.Makmal).  Levitan states that all thedeposits are defined by a close spatialor genetic link to plutons, although itseems that there is also a spatial linkbetween intrusions and many of  thesedimentary-rock hosted deposits.  Thefirst two subgroups are defined as ‘por-phyry gold deposits’ and are stated todiffer from the classic intrusion-relatedgold system at Fort Knox, Alaska, bythe greater abundance of  sulfide min-erals and the more mafic character ofigneous phases.  The vein-type sub-group is further subdivided into gold–quartz and gold-sulfide–quartzdeposits based on sulfide volumes ofless than or greater than five percent,respectively.  Although some of  thesemay indeed be ‘intrusion-related’,descriptions of  other deposits, such asJilau, where ore occurs in the shearedmargins of  plutons, may indicate simi-larities to the sedimentary rock-hosteddeposits.  The gold deposits that arerelated to volcanic rocks are classifiedas gold-telluride (e.g. Zod, Kochbulak),gold related to andesite–dacite (e.g.Kubaka, Baley), and gold–silver or sil-ver related to dacite–rhyolite (e.g.Dukat).  These are generally equivalentto alkalic-related, high sulfidation, andlow sulfidation epithermal precious-metal systems, respectively.The descriptions of  thedeposits summarize the informationavailable from all published sources inthe Russian literature and from Levi-tan’s site visits.  It would have beenhelpful if  the author had been a littlemore critical in evaluating the oftenquite variable information.  For exam-ple, in discussing Muruntau, one para-graph states that the ores formed intwo stages at 245 and 220 Ma, andthus long after magmatism, whereasthe next paragraph reports a 287 Madate for mineralization that is coevalwith magmatism.  Which paragraphshould the readers believe?  Broadranges of  fluid inclusion temperaturesare reported for many deposits, such as465 to 100EC at the Kochbulakepithermal deposit, but what does sucha range tell us about temperatures ofore formation?  A meteoric water ori-gin is stated for the Maiskoye golddeposit based on hydrogen and oxygenisotope compositions of  bulk extrac-tions of  fluid inclusion waters, but issuch an interpretation valid?  Thesetypes of  statements will often leave thereader questioning the validity of  manyinterpretations of  ore genesis in theFSU deposits.  Also, comparisons withdeposits outside of  the FSU are oftenquestionable.  For example, it would begood to know which specific depositsin the ‘southern Appalachians’ resem-ble Sovetskoye and Muruntau.  SukhoiLog is stated to most closely resembleHomestake based upon a similarity inresource tonnage, age, structure, min-eralization style, and metamorphicgrade.  But these deposits are morethan 1 billion years different in age,and Homestake is related to sulfidizedPaleoproterozoic banded iron forma-tion, whereas no such unit is present inthe auriferous Baikal area.  Some ofthe intrusion-related deposits are com-pared to the ‘Alaska-Treadwell ladder-type vein deposit of  the CanadianCordillera’, which obviously refers tothe Alaska-Juneau and Treadwelldeposits of  Alaska, USA, whereigneous host rocks pre-date gold min-eralization by 50-150 my.  Many impor-tant references are included for eachdeposit, although there are longsequences of  text, such as the regionaldescription of  Kumtor on page 72,which lack any referencing.  Too often,names of  various Russian workers areinformally mentioned within the text(i.e. a long list of  authors who havepublished on Muruntau geology, V.Berger’s classification of  Sb-richdeposits, V. Yevstrakhin and M. Itsik-son’s descriptions of  granite-relatedgold deposits, etc.), without any clue asto who these people are or where theyhave published their material.The weakest part of  the bookmay be the figures, although the authorcannot be faulted for some becausebetter figures for certain deposits maynot exist.  The author should also beacknowledged for revising all figures toinclude western-style legends, ratherthan using the typical difficult Russian-style numbered boxes.  Most depositdescriptions are accompanied by alocal geological map that is quite gen-eralized.  For example, the geologicalmap of  the Sovetskoe deposit showsswarms of  veins surrounded by alter-ation assemblages and 'tectonic bound-aries', but no geologic units.  Regionalgeological/lithological maps would behelpful for each area, but are oftenlacking and so the local figures cannotbe put into any regional context.  Evenwhen regional maps are used, they areoften less than satisfactory, such as inthe case of  the Central deposit, wherea 10 x 5 km area is covered by a seriesof  lines defining faults, veins, anddikes, but without any regional geologi-cal background.  The appendix has onegeographic map of  the entire FSU andlocations of  all deposits in the bookare shown on that map (the same mapis shown on the book's front cover at amuch smaller size, yet none of  thenames are readable).In summary, the book servesan important purpose and will be ofuse to those individuals consideringexploration programs in Eurasia orwho want to know more about theeconomic geology of  specific epither-mal and orogenic gold deposits in theFSU.  The listed prices of  $19.99 (US)for paperback and $29.99 (US) forhardcover are very reasonable consid-ering the amount of  difficult to obtaininformation summarized by Levitan.The user should be aware, however,that other sources will be required toobtain a clear understanding of  thetectonic and metallogenic belts thathost the described gold deposits.48GEOLOGICALASSOCIATION OFCANADA(2008-2009)OFFICERSPresidentCarolyn RelfVice-PresidentDaniel LebelPast PresidentCarolyn (‘Lyn) AnglinSecretary-TreasurerToby RiversCOUNCILLORSCarolyn (‘Lyn) AnglinMichel ChampagneTim CorkeryPeter DimmellJohn GosseJeff  HarrisDon JamesEileen van der Flier-KellerJohn KetchumGarth KirkhamDaniel LebelAlain LiardJeff  PackardSteve PierceyCarolyn RelfToby RiversJim TellerSTANDING COMMITTEESCommunications: Tim CorkeryFinance: Michel ChampagnePublications: Jeff  HarrisScience Program: Don James

Gold Deposits of the CIS

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Gold Deposits of the CIS

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