Trace Energy Services was contracted by the Australian National Seismic Imaging Resource (ANSIR) to conduct the WA seismic 2004 survey in the eastern & northern Goldfields region of Western Australia. Recording commenced on the 26th February 2004 on line 04PD-KB1 and was completed by the 27th April 2004 on line 04SI-CQ1. There was a two week shutdown for wet weather in early March. There were 148.59 km of 2D seismic reflection data recorded, 137.54 km over 29 traverses using Litton 315 Paystars and 11.05 km over 5 traverses using a single IVI Minivib as source. All lines were situated within the lease boundaries of gold mining companies, namely, Sons of Gwalia (Tarmoola & Gwalia), Placer Dome (Kanowna Belle, Wallaby, Granny Smith, Lancefield & Mt Morgans), Anglo Gold (Sunrise Dam) and Goldfields (St Ives at Kambalda), Figure 1.

This document contains a list of all seismic reflection surveys conducted onshore by Geoscience Australia (formerly the Australian Geological Survey Organisation and the Bureau of Mineral Resources) between 1949 and the present. There are approximately 170 surveys covering sedimentary basins and mineral provinces throughout Australia. The majority of these surveys are on the Australian mainland. However the list does include early work in the Antarctic as well as early marine work in the Timor Sea and onshore New Zealand. The list contains information on survey area, recording parameters, data storage and published results. Four indices are included at the beginning of the document and a description of the format used to store this information on permanent medium is given in the introduction. This list is to be updated as further surveys are carried out. This report is an update of Bureau of Mineral Resources record 1987/2 and 1990/15.

The Stuart Shelf overlies the eastern portion of the Gawler Craton. This part of the Gawler Craton is South Australia's major mineral province and contains the world-class Olympic Dam Cu-U-Au deposit and the recent Cu and Au discovery at Prominent Hill. The Stuart Shelf is several kilometres thick in places. As such, little is known of the crustal structure of the basement, its crustal evolution or its tectono-stratigraphic relationship to adjacent areas, for example the Curnamona Province in the east. There has been much effort applied to advancing our understanding of basement, mainly through the use of potential field data and deep drilling programmes; though drilling has proved very costly and very hit and miss. The Stuart Shelf area needs new data and methods to bring our knowledge of it to the next level of understanding. At a Gawler Craton seismic planning workshop held in July 2001, stakeholders from industry, government, and university stakeholders identified several criteria fundamental to undertaking any seismic survey within the Gawler Craton. These were - Location of seismic traverse across a known mineral system in order to improve understanding and enhance knowledge of the region's mineral systems. Access to surface and/or drill hole geological knowledge to link geology data with the seismic interpretation. Good coverage of potential field data, and Potential for the seismic data to stimulate area selection and exploration in the survey region.

Gold deposits in the Archaean Eastern Goldfields Province in Western Australia were deposited in greenstone supracrustal rocks by fluids migrating up crustal scale fault zones. Regional ENE-WSW D2 shortening of the supracrustal rocks was detached from lower crustal shortening at a regional sub-horizontal detachment surface which transects stratigraphy below the base of the greenstones. Major gold deposits lie close to D3 strike slip faults that extend through the detachment surface and into the middle to lower crust. The detachment originally formed at a depth near the plastic-viscous transition. In orogenic systems the plastic-viscous transition correlates with a low permeability pressure seal separating essentially lithostatic fluid pressures in the upper crust from supralithostatic fluid pressures in the lower crust. This situation arises from collapse in permeability below the plastic-viscous transition because fluid pressures cannot match the mean stress in the rock. If the low permeability pressure seal is subsequently broken by a through-going fault, fluids below the seal would flow into the upper crust. Large, deeply penetrating faults are therefore ideal for focussing fluid flow into the upper crust. Dilatant deformation associated with sliding on faults or the development of shear zones above the seal will lead to tensile failure and fluid-filled extension fractures. In compressional orogens, the extensional fractures would be sub-horizontal, have poor vertical connectivity for fluid movement and could behave as fluids reservoirs. Seismic bright spots at 15-25 km depth in Tibet, Japan and the western United States have been described as examples of present day water or magma concentrations within orogens. The likely drop in rock strength associated with overpressured fluid-rich zones would make this region just above the plastic-viscous transition an ideal depth range to nucleate a regional detachment surface in a deforming crust.

The Tasmante cruise (AGSO Cruise 125) started in Auckland on 12 February 1994, and ended in Adelaide on 29 March 1994 (Fig. 1). The cruise used the French research vessel l'Atalante on an exchange basis. The French vessel was used rather than Rig Seismic because of the wide-angleswath-mapping capability of its SIMRAD EM12D system. Data were recorded on transits, as well as off Tasmania, our main area of interest (Figs. 1 & 2). The swath-mapping system functioned well throughout. The maps produced are mostly at 1:250 000 scale, and cover the transit from New Zealand (T1-77), the detailed survey off Tasmania (C1-C7), and the transit to Adelaide (T8-T9). The suite of maps generally includes ship tracks, sonar imagery, detailed and less detailed contour maps (25 and 50 m contours), and an overlay of sonar imagery on the less detailed contours. In addition, 1:1 000 000 scale maps of the entire Tasmanian survey area were produced of bathymetry (50 m contours) and imagery. Finally, 1:100 000 scale maps were provided of two fisheries areas off Tasmania: 20 m contours and imagery in thesouth, and 20 m contours in the west.

Legacy product - no abstract available

Legacy product - no abstract available

Most crustal-scale seismic reflection surveys use single profiles, and are an attempt to create two-dimensional images of three-dimensional structures. CMP data are stacked and migrated assuming that the seismic energy comes from within the plane of the section. However, three-dimensional topography on an interface results in out-of-plane reflected energy coming into the plane of the section, and energy from the plane of the section being lost from the plane of the section. Interfaces with low to moderate relief image as a zone of reflections in which the top of the zone reproduces the shape of the interface within the plane of the reflector fairly accurately, and energy lower in the zone of reflections is from out of the plane. However, if the relief on the interface is significant, reflections from shallower levels of the interface out of the plane of the section can arrive before those from deeper parts of the interface in the plane of the section. This makes interpreting both the position of the interface in the plane of the section and the amount of relief on the interface difficult. Three-dimensional topography on the interface out of the plane of the section generates more diffractions than does two dimensional topography. The amount and nature of diffracted energy in stacked data is a qualitative indicator of structure in and out of the plane of the section. For a synthetic three-dimensional interface with relief ranging over a number of wavelengths, reflection amplitudes up to twice the primary reflection strength were observed; destructive interference produced very weak reflections elsewhere. The absolute amplitude of the strongest reflections is therefore a poor indicator of impedance contrast for reflectors with significant three-dimensional topography.

Legacy product - no abstract available

One's understanding of the crustal architecture of Australia's Archaean Yilgarn Craton has increased greatly over the last few years with the collection a range of different seismic data types. The seismic data collected range from broadband seismic studies using distant earthquakes to study lithospheric scale problems, receiver function studies to obtain crustal velocity variations, deep seismic reflection transects to image province to mine scale studies on specific structural problems within the top few kilometres of the crust. At the craton scale, broadband deployments, recording P-wave, S-wave and surface wave variations, have been used to develop 3D velocity models of the craton. These velocity models allow researchers and the Yilgarn Craton mineral industry to understand the larger picture variations within the craton. An interesting feature of the data, easily identified in 3D, is the presence of a fast S-wave velocity anomaly (> 4.8 km.s-1) within the upper mantle. This anomaly is east-dipping and has a series of step-down offsets that coincide approximately with terrain boundaries. Receiver function results show significant variation in crustal and upper mantle velocities across the craton. The receiver function results for the depth to the Moho are consistent with the deep seismic reflection data; both show an increase in depth to the east. Refraction results have provided the framework for the construction of a 3D crustal architecture of the Eastern Yilgarn Craton that suggests the dominant geodynamic process involved the development of a foreland basin with its associated contractional folding and thrusting events. This contractional event were separated by equally important extension events, with the seismic reflection data suggesting that extensional movement on shear zones was more common that previously thought. The seismic reflection suggests that the dominant mineral systems operating involved fluid flow up along crustal-penetrating shear zones. These seismic data have proved invaluable in constraining the crustal geometry of the Yilgarn Craton and in developing three-dimensional models of the crust and upper mantle of the Yilgarn Craton, Australia. In all these data sets, ANSIR, the Australian National Seismic Imaging Facility, is acknowledged for its part in the provision of equipment and expertise and in the data collection phases of the work