GEOLOGICAL SURVEY OF WESTERN AUSTRALIA ANNUAL REVIEW 1995–96 GEOLOGICAL SURVEY OF WESTERN AUSTRALIA GEOLOGICAL SURVEY OF WESTERN AUSTRALIA ANNUAL REVIEW 1995–96 Perth 1996 MINISTER FOR MINES The Hon. Kevin Minson, MLA DIRECTOR GENERAL K. R. Perry DIRECTOR, GEOLOGICAL SURVEY OF WESTERN AUSTRALIA Pietro Guj Copy editor: I. R. Nowak The recommended reference for this publication is: (a) For reference to an individual contribution SHEPPARD, S., 1996, Mafic–felsic magma mingling in the Bow River batholith of the Halls Creek Orogen: Western Australia Geological Survey, Annual Review 1995–96, p. 56–60. (b) For general reference to the publication GEOLOGICAL SURVEY OF WESTERN AUSTRALIA, 1996, Geological Survey of Western Australia Annual Review 1995–96: Western Australia Geological Survey, 223p. ISBN 0 7309 6543 0 ISSN 1324-504 X Cover: Mississippi Valley-type marcasite–sphalerite ore from Goongewa mine, Lennard Shelf, Canning Basin. Deposit is hosted in platform-facies limestones of the Devonian reef complexes. Frontispiece: Helicopter taking off from base station during GSWA gravity survey of the Merlinleigh Sub-basin near Gascoyne Junction. One GPS antenna is set on a tripod over the base station and another is mounted on the helicopter to fix the gravity stations by differential GPS technique. Foreword Foreword It gives me pleasure to introduce you to the Geological Survey of Western Australia Annual Review for 1995–96 — our third issue. I take this opportunity to thank you, the reader, for your constructive feedback on the previous issues which, I hope, has been reflected in an improvement in quality and relevance. I have also been very flattered by, but have resisted, the suggestion that GSWA should charge for its Annual Review. I think of the Review as our “loss leader”, the means to whet your appetite for new products to come. It is also confirmation that we care about keeping our stakeholders well informed about our programs and activities, and that we take our accountability seriously. The Review is also meant to be a tribute to GSWA staff, to recognize their competence, effort and dedication in serving our customers and in achieving what amounted to very demanding milestones and productivity targets in 1995–96. I like to believe that they will take pride in distributing it to their most immediate clients, colleagues and associates. I am confident, too, that the variety of feature articles and previews of significant preliminary results from various active projects will stimulate interest in new areas, and inspire new exploration and research concepts. Finally, we have succeeded in our intention of publishing the Annual Review just before the end of the relevant calendar year; thus its content is reasonably up-to-date with the current state of play. Of course, if you have a specific interest in any of our projects, or for that matter in anything geological at all, please feel free to contact the appropriate officer who will be only too pleased to help. Good hunting. P. Guj DIRECTOR v Geological Survey of Western Australia 1995–96 Annual Review vi Contents Contents Foreword ......................................................................................... v Mission statement ......................................................................... ix Feature articles ............................................................................... 1 Technical papers ........................................................................... 39 Program review ........................................................................... 177 Appendices.................................................................................. 215 vii Geological Survey of Western Australia 1995–96 Annual Review viii Mission statement Geological Survey of Western Australia A century of service to a million mile State Our vision is to be the international benchmark for delivery of high-quality geoscientific products and services to industry, Government, and the public, making Western Australia the focus of international exploration. Our commitment is to provide, in a timely and courteous manner, up to date regional geoscientific data and information to the mining and petroleum industries, Government, and the public to encourage and support resource exploration and landuse planning. Our role is to systematically record and interpret the geology of the State and to provide this information to Government, industry, and the general public to assist with the exploration, development, and conservation of the State’s mineral (including groundwater) and petroleum resources. The Geological Survey also evaluates mineral and petroleum resources as a basis for decision making by Government, and assists and advises on a variety of community needs, including urban planning and landuse matters. Our strengths are in field-based research, especially regional geological mapping in both the Precambrian and Phanerozoic provinces of the State. The Survey is also strong in the fields of structural geology, basin studies, carbonate sedimentology, mineralization studies, hydrogeology, geochemistry, regolith studies, geochronology, geoscientific computer applications, palaeontology, and petrology. Other areas of expertise include mineral economics, and financial modelling and evaluation of resources projects. As a result of the application of these skills for over 100 years, and of its role as the depository of mineral and petroleum exploration reports, the Geological Survey is the custodian of an immense volume of information on the geology of the State and has become the premier pool of geoscientific expertise in Western Australia. ix Geological Survey of Western Australia 1995–96 Annual Review x Feature articles Feature articles The year in review by P. Guj .............................................................................................................. 3 A history of hydrogeology in the Geological Survey of Western Australia 1888–1995 by A. D. Allen ..................................................................................................... 11 Mineral exploration in Western Australia in 1995–96 by W. A. Preston................................................................................................ 22 Inside the GSWA Profiles ..................................................................................................... 30 Staff list .................................................................................................... 33 Staff movements: 1/07/95–30/06/96 ........................................................ 35 Organizational chart ................................................................................. 36 Key contacts ............................................................................................ 37 1 Geological Survey of Western Australia 1995–96 Annual Review 2 The year in review Feature articles The year in review by P. Guj Well, when the going gets tough . Truth is that, surprisingly, we just made it; we achieved all the products and services, output milestones and a total productivity target of over 7% improvement (4% real) for 1995/96. I say surprisingly, because when we agreed to finalize the restructuring of the Geological Survey of Western Australia (GSWA) within a flat (5 strata) new Departmental organization and to introduce a new Performance Enhancement Program (PEP) linking our pay increases to our performance, we took a major step into uncharted waters. Uncharted waters in two respects. Firstly, we were embarking on a very significant cultural change for a traditional and largely static public service environment. And secondly, in retrospect, we only had a vague idea of the commitment in time and effort required to succeed in implementing effective structural reform throughout our organization, and the heavy toll it takes on its leaders. It is always hard to realise other people’s obsessions, at least until one also becomes totally committed. It is also hard to divorce one’s attitudes to change from the initial perceptions that are clouded by potential, or imagined, threats to one’s own self-interest. It is hard for staff to make an objective and detached assessment of the situation, of the motives and of the significant organizational and indeed personal opportunities inherent in change. It is not enough, in the first instance, that change makes considerable rational and analytical sense at the level of the decision makers. Nonetheless, the GSWA vision to become an international benchmark for geological surveys will only be achieved with a flatter, leaner and meaner organization where, over time, more highly skilled and productive, motivated and relatively well-paid geoscientists excel in fulfilling the GSWA role of enhancing and promoting the State’s prospectivity, and contributing to making Western Australia the focus of international exploration investment. For this vision to be fully realised it must be sold to, and accepted by, not only all staff but also Government decision makers. The formality of a new stratified structure (displayed schematically else- where in this publication) and of performance assessment systems by themselves, however, will not realise the vision unless all GSWA staff understand, work within, and make a commitment to our new management system. A first step in this direction has also been taken in 1995–96 with the introduction of Workplace and Enterprise Bargaining Agreements within the Department of Minerals and Energy (DME). The Workplace