The Australian Geological Survey Organisation (AGSO) through the partnership in the Australian Geodynamics Cooperative Research Centre (AGCRC) and Kalgoorlie Consolidated Gold Mines (KCGM) completed a joint research project to image the crustal structure of the Kalgoorlie region to develop a knowledge of the shallow and deep structures, tectonics, and fluid migration pathways. The Australian National Seismic Imaging Resource (ANSIR) was contracted to acquire the seismic data. The project's objectives were to obtain a better understanding of - sub-surface geology at a regional and mine scale - provide more information on regional crustal thickness and major features - stratigraphic and structural architecture of the mineral system - timing and locations of fluid migration pathways The seismic survey obtained 25 km of 10 fold CMP (common midpoint) regional reflection seismic data along two traverses and 8 km of 10 fold CMP high-resolution reflection seismic data along another two traverses. The data are of good quality and similar to both the 1991 and 1999 Eastern Goldfields reflection seismic data to the north and south of the survey area. The major outcome of imaging the four localities included mapping the Golden Mile and Bolder-Lefroy Faults, and the Boorara Shear at depth. This new information indicates the Golden Mile Mine was fed by a suite of relatively minor faults dangling off the major crustal-scale Boorara Shear. The dangling element relates to percolation theory. The detachment surface was imaged on all seismic traverses. Thrust duplexes were interpreted above the detachment surface.

Legacy product - no abstract available

Palaeoproterozoic tectonics and metallogenesis: comparative analysis of parts of the Australian and Fennoscandian Shields. Papers for a Workshop, Darwin, Australian Geological Survey Organisation.

Legacy product - no abstract available

Legacy product - no abstract available

In 1997, AGSO - Geoscience Australia (GA) and the Tectonics Special Research Centre (TSRC) at the University of Western Australian (UWA) and Curtin University conducted a joint research project to image the crustal setting of the Hamersley Province of northern Western Australia. This joint research was aimed at investigating the shallow structure of the Hamersley Province, the regions deeper basement structure and in so doing, developing an understanding of the region's tectonics and possible fluid migration pathways. The project's objectives were to obtain a better understanding of sub-surface geology of the Hamersley Province at both a regional scale and a mine scale. In particular, the project's objectives were to provide more information on: * regional crustal thickness and major features, * stratigraphic architecture of the regions mineral system, * structural architecture of the mineral system, * timing and locations of fluid migration pathways The seismic survey obtained 132 km of nominally 10 fold CMP (common midpoint) deep reflection seismic data along two transects over approximately 5 weeks of acquisition.

No abstract available

A prospectivity assessment of the offshore northern Perth Basin, Western Australia, was undertaken as part of the Australian Goverment's Offshore Energy Security Program.

The Tanami region of the Northern Territory lies approximately 600 km north-west of Alice Springs and is a major Australian gold province. A thin veneer of Cainozoic sand and gravel largely obscures basement host rocks, posing considerable challenges to mineral explorers looking for buried deposits. Recent multi-disciplinary investigations rely on the integration of geophysical data with more traditional field techniques to map sub-surface structure, stratigraphy and identify potential mineralised targets (Hendrickx et al., 2000a,b, Crispe and Vandenberg, in prep). While two dimensional (2-D) mapping of the subsurface has been relatively straightforward, three dimensional (3-D) reconstruction of the regional structure and stratigraphic architecture is more difficult given the lack of continuous exposure and vast distances between outcrops. In this study 19 2-D geological cross-sections were tested via ModelVision, a 21/2-D potential field modelling package, to a depth of 15 km. Sections were revised and remodelled till geological relationships and geometries across serial sections approached a reasonable level of consistency. The modelled sections were then captured in GOCAD, a 3-D earth modelling system. This enabled the interpolation of fault surfaces, major contacts and granitic bodies to produce a 3-D geological model (Fig. 1). The modelled sections, surfaces and other data sets were then combined in Virtual Reality Modelling Language (VRML) to create 3-D views of the geology (Vandenberg and Meixner, 2004). The resulting model provides a 3-D framework in which various data sets and interpretations can be visualised and compared. The model can evolve as new data is incorporated, and provides a base for the construction of further tests to refine our understanding of the geology and associated mineral systems.

Despite the clear unambiguous link between gold mineralisation and structural control in the well-endowed eastern Yilgarn Craton (EYC), the tectonic history of this region remains controversial. The current paradigm describes the tectonic history to have evolved in a relatively simple progressive manner with the main `D2? and subsequent events (D3 and D4) being the result of maximum shortening oriented ~E?W or ENE?WSW. Although most previous studies have focussed on the structural geology of the greenstones, both greenstones and granites (Fig. 1) have been assumed to have experienced the same event history (Swager, 1997: Precambrian Research 83, 11-41). This article outlines a new approach taken to better understand the tectonic and geodynamic evolution of this important part of Australia.