The guide develops exploration strategies for gold, base metals,nickel <strong>and</strong> surficial uranium deposits within the context <strong>of</strong> theevolution <strong>of</strong> the l<strong>and</strong>scape <strong>and</strong> regolith <strong>of</strong> the Yilgarn Craton. Inmany instances, this paper alone should provide the explorer with a‘one-stop shop’ with respect to the knowledge required to plan <strong>and</strong>execute effective geochemical exploration strategies. However, thepaper has a comprehensive reference list if more detail is sought ona particular topic or for a particular area. The illustrations includephotographs <strong>of</strong> relevant regolith materials, real examples <strong>of</strong> maps<strong>and</strong> sections as <strong>well</strong> as schematic block diagrams. The guide includesflow charts that demonstrate the process <strong>of</strong> regolith mapping <strong>and</strong>procedures for selecting the optimum geochemical sampling strategyfor a particular area.The guide commences with a brief introduction to the geology<strong>and</strong> principal ore deposits <strong>of</strong> the craton, followed by a description<strong>of</strong> the development <strong>and</strong> characteristics <strong>of</strong> the regolith, <strong>and</strong> therelationship between regolith type <strong>and</strong> l<strong>and</strong>forms. The Regolithsection provides a succinct <strong>and</strong> accessible summary <strong>of</strong> the vast body<strong>of</strong> research on this topic, <strong>and</strong> presents it as a coherent synthesis thatmust underpin any thinking about geochemical exploration in theYilgarn. The distribution, characteristics <strong>and</strong> use <strong>of</strong> the principalsample media are described. The regolith <strong>and</strong> l<strong>and</strong>forms providea framework for empirical models that describe the processes <strong>of</strong>geochemical dispersion, based on numerous case histories <strong>and</strong> otherinvestigations, grouped according to the principal commodities.The models anticipate <strong>and</strong> summarise the surface expression <strong>of</strong>mineralisation <strong>and</strong> include recommendations on explorationprocedures, such as sample selection, sampling interval, analysis <strong>and</strong>data interpretation.Ravi An<strong>and</strong> is a Chief Research Scientist at CSIRO <strong>and</strong> an AdjunctPr<strong>of</strong>essor in regolith geology <strong>and</strong> geochemistry at Curtin University,Perth, Western <strong>Australia</strong>. In 1984, Ravi completed his PhD on weatheringprocesses at the University <strong>of</strong> Western <strong>Australia</strong> (UWA).He then became a postdoctoral fellow at UWA. He joined CSIRO in1987 as a Research Scientist in the Division <strong>of</strong> Mineralogy, carryingout research into methods <strong>of</strong> exploring for concealed mineraldeposits in <strong>Australia</strong>’s deeply weathered terrains. Ravi wasApplications Coordinator <strong>of</strong> the CRC for L<strong>and</strong>scape Evolution <strong>and</strong>Mineral Exploration (1995–2001) <strong>and</strong> Program Leader <strong>of</strong> Program 2for L<strong>and</strong>scape Environments <strong>and</strong> Mineral Exploration (2001–2008).He has been a leader <strong>of</strong> industry-funded projects since 1990. Theseprojects have included multidisciplinary, multi-client projectsthrough <strong>Australia</strong>n Mineral Industries Research Association Ltd(AMIRA) <strong>and</strong> projects with individual companies. The outcomes <strong>of</strong>his research have been major contributors to the discovery <strong>of</strong> manymineral deposits in deeply weathered terrains. Ravi has authoredover 220 publications <strong>and</strong> scientific reports <strong>and</strong> four monographsor journal issues. Recognition <strong>of</strong> Dr An<strong>and</strong>’s achievement inregolith-geochemical research is demonstrated by awards <strong>and</strong>invitations to international conferences <strong>and</strong> media releases.Charles ButtCharles Butt was appointed to CSIRO in 1971 after completing a PhDin Applied Geochemistry at Imperial College, London. His researchconcentrated on developing geochemical exploration procedures forgold, nickel, platinum group elements (PGE) <strong>and</strong> base metals indeeply weathered terrains. He also concentrated on the geology <strong>of</strong>secondary mineral deposits, particularly nickel laterites, supergenegold <strong>and</strong> calcrete uranium. He led a number <strong>of</strong> projects in regolithgeochemistry through AMIRA, was Program Leader <strong>and</strong> DeputyDirector for CRC LEME1 <strong>and</strong> Chief Scientist for CSIRO Exploration<strong>and</strong> Mining. Charles Butt was elected a Fellow <strong>of</strong> the <strong>Australia</strong>nAcademy <strong>of</strong> Technological Sciences <strong>and</strong> Engineering in 2004 <strong>and</strong>appointed a CSIRO Fellow in 2007. He retired in 2011 <strong>and</strong> is nowan Honorary Research Fellow with CSIRO Earth Science <strong>and</strong> ResourceEngineering.Richard MorrisRichard Morris has been a CSIRO Honorary Research Fellow sinceretiring in 1996. He gained a BSc in geology in 1958 at UWA parttimewhile working as ‘the lab boy’ in the Department <strong>of</strong> Geology.After graduating, Dick worked in the WA Department <strong>of</strong> Mines as amineralogist until 1970, before going into petrographic consulting ongossans, ores, mineral s<strong>and</strong>s <strong>and</strong> regolith samples. A four-monthproject in 1972 with Wilf Ewers, head <strong>of</strong> the CSIRO WA Division <strong>of</strong>Mineralogy, introduced Morris to the complexities <strong>of</strong> Hamersleyb<strong>and</strong>ed iron formation (BIF) <strong>and</strong> its phosphorus distribution. Thisproject led to Wilf, a geochemist, inviting Dick in 1976 to be hispetrological assistant for two years in the inaugural CSIRO–AMIRA‘Phosphorus in Iron Ores <strong>of</strong> the Hamersley Province’ program. The twoyears became 18, with Morris taking over the program when Wilfretired in 1981. The overall project involved detailed BIF/orepetrographic <strong>and</strong> analytical studies, with allied research involvingmajor contributions from other CSIRO staff: RC Horwitz in joint fieldstudies, MR Thornber in electrochemical modelling <strong>and</strong> AB Fletcherin demonstrating enhanced solubility <strong>of</strong> quartz during ferrous–ferricreactions. AMIRA-funded collaborative research continued on ‘shales’in ore with LH Seet, asbestos in ores with Jiri Just, channel irondeposits (CID) with ER Ramanaidou, Indian iron ores, <strong>and</strong> finally aparallel study on detrital iron deposits (DID) that concluded theCSIRO–AMIRA program in 1994. In 1985 Morris completed anexternal PhD (UWA) on the BIF-hosted bedded iron deposits (BID) <strong>and</strong>was awarded the GSA (WA) 1988 Gibb Maitl<strong>and</strong> Medal for his ironore research.Malcolm KneeshawMalcolm Kneeshaw qualified with a BSc in Geology in 1965 fromthe University <strong>of</strong> Hull in the UK <strong>and</strong> is a Fellow <strong>of</strong> The AusIMM. Aftera brief exposure to iron ore at BHP’s Middleback operations, heworked in iron, nickel <strong>and</strong> manganese exploration for BHP MineralsExploration in the Pilbara <strong>and</strong> Yilgarn in the 1960s, including someTAG September 2012| 13
<strong>of</strong> the early exploration drilling in BHP’s then Robe River CIDtenements, <strong>and</strong> BID at Mt Whaleback. Moves to BHP’s iron oreoperations at Koolyanobbing <strong>and</strong> Yampi followed, before a return toMt Whaleback in 1970 as Senior Mine Geologist with Mt NewmanMining. This period saw the 1800-million-tonne Whaleback drilloutcompleted, with mine geology <strong>and</strong> quality-control duties set upunder the then Chief Geologist, Bill Willis. Bill was responsible forBHP’s joining the AMIRA–CSIRO iron ore program in 1976.From 1981 to 2004 as Chief Geologist Mt Newman Mining/Manager Geology BHP Iron Ore, Mal was responsible for allexploration, development <strong>and</strong> metallurgical sampling work in BHPBilliton’s Pilbara tenements, which from the mid-1980s led to thedevelopment <strong>of</strong> BHP Billiton’s satellite mines in the Newman area,<strong>and</strong> new operations at Y<strong>and</strong>i, Jimblebar, Yarrie <strong>and</strong> Area C. In 2004,he received the Gibb Maitl<strong>and</strong> Medal for contributions to iron oregeoscience in WA. Mal would specifically like to record the able <strong>and</strong>pr<strong>of</strong>essional assistance <strong>of</strong> Ilmar Tehnas, Doug Kepert <strong>and</strong> MarkPudovskis during this hectic period in evaluating, developing <strong>and</strong>underst<strong>and</strong>ing the Hamersley’s various BID, CID <strong>and</strong> DID. Sinceretiring from BHP in 2004, he occasionally acts as a consultant withC<strong>of</strong>fey Mining on iron ore projects <strong>and</strong> mines in the Pilbara, Yilgarn,Northern Territory <strong>and</strong> South <strong>Australia</strong>.The CSIRO–AMIRA 1976–1994 program owes its success to theforesight <strong>and</strong> h<strong>and</strong>s-on leadership <strong>of</strong> Wilf Ewers, who initiated thepilot BIF–phosphorus study by Morris in 1972. He invited the variousHamersley iron ore companies to join CSIRO in a detailed comparableiron ore study, since the then-known low-phosphorus high-gradehematite ore resource was limited. The initial sponsors in 1976 werethe BHP Company Limited, Mt Newman Mining Co Pty Ltd <strong>and</strong>Hamersley Iron Pty Ltd (through Hamersley Exploration), eventuallyincluding CRA, Robe River Associates <strong>and</strong> Hancock Prospecting. Closecollaboration between company senior geoscientists such as JohnEvans, Richard Harmsworth <strong>and</strong> Chris Robinson, <strong>and</strong> the CSIROresearchers, produced the results that retained the sponsors’ supportfrom 1976 to 1994.The partnership between geologist Mal Kneeshaw <strong>and</strong> microscopeoperator Dick Morris helped enhance many <strong>of</strong> the varied CSIROsponsor reports <strong>and</strong> journal papers, <strong>and</strong> led to the 2007 FL Stil<strong>well</strong>Medal for Morris <strong>and</strong> Ramanaidou on the genesis <strong>of</strong> the CID. ThisAB Edwards Award is a further example <strong>of</strong> that continuing partnership.Kneebone <strong>and</strong> Morris state, “Our paper is an attempt to bringsome objectivity to the clash between the supergene <strong>and</strong> thehydrothermal genetic model advocates. We are grateful to ourreviewers for their help, to AJES Editor Anita Andrew for herpainstaking work on the manuscript, <strong>and</strong> to the Specialist Group inEconomic Geology <strong>of</strong> the <strong>Geological</strong> <strong>Society</strong> <strong>of</strong> <strong>Australia</strong> forhonouring us with this prized medal.”14 |TAG September 2012