Legacy product - no abstract available

Current geological mapping by the Northern Territory Geological Survey is leading to a much better understanding of the surface geology of the Territory. Less well understood is the geometry of the Northern Territory in the third dimension, although this has been predicted by the construction of cross sections (e.g. on recent 1:250 000 geological maps). At shallow depths, the cross sections can be constrained by drilling results, if available, but deeper levels can only be examined by geophysical techniques such as seismic reflection or magnetotelluric profiling, or by modelling of potential field data. Text of paper presented at the NTGS AGES 2002 Workshop, Alice Springs, 26-27 March 2002.

In 2006, deep seismic reflection profiling was carried out along six transects across the Mount Isa Inlier. The seismic lines were jointly funded by the Geological Survey of Queensland, Geoscience Australia, the Predictive Mineral Discovery Cooperative Research Centre and Zinifex Pty Ltd. (now Oz Minerals). In 2007, a further three seismic lines were collected by Geoscience Australia and the Geological Survey of Queensland from Cloncurry to south of Charters Towers via Croydon and Georgetown. This paper presents some highlights from the geological interpretations of the seismic lines.

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.

As part of the Australian Government's Onshore Energy Security Program and the Queensland Government's Smart Mining and Smart Exploration initiatives, deep seismic reflection surveys were conducted in North Queensland to establish the architecture and geodynamic framework of this area in 2006 (Mt Isa Survey; also involving OZ Minerals and pmd*CRC) and 2007 (Cloncurry-Georgetown-Charters Towers Survey; also involving AuScope). Nearly 2300 line km of seismic data were acquired during these surveys. Geochemical, geochronological and complementary geophysical studies were undertaken in support of the seismic acquisition. Overviews of the geology of North Queensland and more detailed descriptions and the results of these surveys are presented in Hutton et al. (2009a, b), Korsch et al. (2009a), Withnall et al. (2009a, b), Henderson and Withnall (2009), and Henderson et al. (2009). The purpose here is to use the new geodynamic insights inferred from these data to provide comments on the large-scale geodynamic controls on energy and other mineral potential in North Queensland. This contribution draws on geodynamic and metallogenic overviews presented by Korsch et al. (2009b) and Huston et al. (2009)

The Record contains extended abstracts to accompany presentations at the GOMA (Gawler Craton-Officer Basin-Musgrave Province-Amadeus Basin) seismic and MT workshop, Adelaide 25 November 2010.

Legacy product - no abstract available

The Sedimentary basins of eastern Australia project undertook structural and sequence stratigraphic mapping of a regional grid of seismic reflection data in the Bowen, Gunnedah and Surat Basins (usually 4 seconds two-way travel time data, with about 15,000 line km of data on about 1200 individual seismic lines). The seismic mapping was used to define the interplate and intraplate tectonic events that have helped to create the accommodation space and also to define the stratal geometry of the sedimentary units. Thus, the mapping provided the overall geometry of the basin system as well as the geometry of several of the sequence boundaries, resulting in the development of a new sequence stratigraphic framework for the basins. These results were also compiled into a series of structure contour and isopach maps, which have been used to build a 3D geological map of the Bowen Gunnedah and Surat Basins.

The granite-greenstone terrains of the Eastern Goldfields Province, Yilgarn Craton, are extremely important as a major Australian gold province. The Kalgoorlie region, in particular, hosts several world class gold deposits. A grid of deep seismic reflection lines was acquired in 1999 to examine the three-dimensional geometry of the major structural features in the region within an area of the Kalgoorlie - Ora Banda region of the Eastern Goldfields Province, Yilgarn Craton. These seismic lines presented an ideal opportunity to further develop our 3D understanding of this highly mineralised granite-greenstone terrain. The seismic grid tied into the earlier 1991 regional deep seismic traverse and the more recent 1997 regional and high-resolution profiles acquired in the region. It covered and area approximately 50 km square that extended to a depth of approximately 35 km (ie the base of the crust in this area). The resulting seismic grid was well suited to the development of a three-dimensional model of the region that could be used to investigate the spatial relationships of the greenstones and the granites. The 3D geological model of this region was built using a 3D modelling software package, GOCAD(r). It was built using surface geological data and geological interpretations of the region's deep and high-resolution seismic reflection profiles. The latter seismic interpretations were constrained by gravity modelling.

No abstract available