vii

INTRODUCTION

AEG AUSTRALIA REGIONAL MEETING VOLUME

Much geochemical exploration conducted in Australia, and, indeed, in many other countries in the Southern Hemisphere takes place in deeply weathered and/or arid environments. With this in mind the Australian Branch of the Association of Exploration Geochemists held a three-day Regional Meeting in Perth, Western Australia, in May 1983 attracting some 150 registrants. The theme "Geochemical exploration in arid and deeply weathered environments" was covered by 26 technical papers. The meeting was opened by the then Hon. Minister for Mines for Western Australia, the Hon. P.M. Dowding and a keynote address was provided by the Aus- tralian councillor for the Association, Dr R.H. MazzuccheUi.

A further five papers, not reproduced in this volume, were presented at a joint session with the Specialist Group in Economic Geology of the Geological Society of Australia and entitled "The geochemistry and genesis of ore deposits associated with weathering".

The technical sessions aroused a high level of interest which was further reflected in the numbers of members attending field excursions run in conjunction with the Meeting. Excursions included visits to Archaean gold, volcanogenic base metal and nickel sulphide deposits and to a lateritic nickel deposit.

Overall the Australian Regional Meeting was a most rewarding and enjoy- able occasion and the contributions by the speakers, the excursion leaders, the members of the organizing committee and the session chairmen to the smooth running of all parts of the Meeting are gratefully acknowledged.

This Proceedings Volume includes full papers, and abstracts for the re- mainder of the technical papers presented under the main theme. Several papers presented here in abstract are to appear or have appeared elsewhere. These include:

Butt, C.R.M. and Gole, M., 1984. Helium determinations in mineral ex- ploration. Final Report, National Energy Development and Demonstra- tion Programs, Australia.

Cart, G. et al., Submitted to J. Geochem. Explor. as a separatepaper. Thornber, M.R. and Wildman, J.R., 1984. Supergene alteration of sulphides,

vi: The binding of Cu, Ni, Zn, Co and Pb with gossan (iron-bearing) min- erals. Chem. Geol., 44: 399--434.

Giblin, A. and Dickson, B.L. to be offered to J, Geochem. Explor. at a later date.

van Moort, J.C. and Swanson, C.G., 1982. The oxidized zone of the Broken Hill Lode, N.S.W. In: G.C. Amstutz et al. (Editors) "Ore Genesis -- the State of the Art". Springer-Verlag, Berlin, pp. 251--268.

0375-6742/84/$03.00 © 1984 Elsevier Science Publishers B.V.

viii

A modified version of the keynote address by R.H. Mazzucchelli is to be included in a special publication "Applied geochemistry in the 1980s", edited by I. Thornton and published by Shiva of London.

Acknowledgements axe due to the various companies and institutions who made staff and facilities available for the organization of the Meeting:

Agnew Mining Ltd Analabs Asarco (Aust) Pty Ltd Central Norseman Gold Corp. N.L. CSIRO Division of Mineralogy Esso Minerals Geological Survey of Western Australia Geopeko Kalgoorlie Mining Associates Noranda Australia Ltd University of Western Australia Western Mining Corporation Ltd

Thanks are also due to the many anonymous reviewers whose suggestions improved these published papers.

R. DAVY, Geological Survey of Western Australia R.H. MAZZUCCHELLI, Western Mining Corporation

Regional Meeting Committee

R.H. Mazzucchelli (Chairman) Western Mining Corporation Ltd. R.A. Young (Secretary), Western Mining Corporation Ltd. T.A. Ballinger, Geopeko C.R.M. Butt, CSIRO Division of Mineralogy M.A. Chapman, Analabs R. Davy, Geological Survey of Western Australia P.G. Harris, University of Western Australia B.H. Smith, Western Mining Corporation, Ltd. R.E. Smith, CSIRO Division of Mineralogy G.C. Sylvester, Noranda Australia Ltd. H.C. WiUiamson, ASARCO (Australia) Pty Ltd.