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  • <p>Geoscience Australia conducted the Gunnedah Basin Seismic Survey during January to April 1991. The major aim of the seismic survey was to record deep seismic reflection data across the Gunnedah Basin and bounding margins. The seismic survey would also address several problems relating to the geometry of structural units and major faults. The survey recorded 253 km of eight-fold Common-Middle-Point (CMP) seismic data. The seismic data have been processed, with the data showing good seismic reflection images of the main structural features targeted in the seismic survey.<p><b>Raw data for this survey are available on request from clientservices@ga.gov.au - Quote eCat# 74952</b>

  • Seismic reflection survey has been conducted to help identify the possible oil-bearing structures, which were revealed by two residual gravity anomalies in a geophysical survey made by the Bureau of Mineral Resources. Good reflections were obtained in some parts of the area, but the quality was not consistent. The seismic results appear to confirm a small closure near one of the gravity anomalies. No definite closure is shown near the other anomaly.

  • The seismic survey made by the Geophysical Section of the Bureau of Mineral Resources to assist in the search for oil in the Carnarvon (North-West) Basin of Western Australia. The seismic field work in the Carnarvon Basin was confined to one field season, i.e., from April to December 1951, and consisted of surveys on the Capa Range and Giralia Anticlines. Both refraction and reflection methods were used. The purpose of the seismic work was to determine if the structures at surface extended to depth and thus establish if a suitable site for a deep exploration drill hole exist. The seismic work has shown that seismic methods are applicable in the investigation of possible oil-bearing struotures in the Carnarvon Basin. It is clear from the results obtained on the Giralia Anticline, that investigation with a view to tile selection ot deep drilling sites cannot be carried out thoroughly without seismic surveys of selected areas.

  • Techniques for recording deep crustal reflections were developed on an experimental seismic survey at Mildura, Victoria and Broken Hill, NSW, during September to December 1968. The survey was carried out preparatory to a seismic reflection survey on the 'Geotraverse' project, a project initiated by the Australian Upper Mantle Commitee to study the Earth's crust and upper mantle along a line across the Precambrian shield in Western Australia.

  • The seismic reflection survey was undertaken by the Bureau of Mineral Resources on top of gravity and magnetic surveys in the Gippsland Lakes district, Victoria. The aim of the seismic survey is to convience the favourable structure to the accumulation of oil being present on the overlying Tertiary rocks. Two north-south traverses and one running east-west and crossing the other two were surveyed.

  • A seismic velocity survey was carried out in Associated Freney Oilfields Nerrima No. 1 Bore by the Bureau of Mineral Resources on the 10th August 1955. The well is situated on the Nerrima Dome in the Fitzroy Basin, W.A. Some trouble was experienced with cable breaks for the shallow part of the hole, but in general it was possible to recognise the true formation break. Average measured velocities ranged from 8000 ft/sec near the top to 12,200 ft/sec for the total depth of the bore.

  • Middalya in the Carnarvon Basin, Western Australia, during October 1955 by the Bureau of Mineral resources. The object of the survey was to assist in interpreting gravity results in the region. Prior to this survey the interpretation of the geology suggested that the deepest part of the Palaeozoic basin was in the Wandagee Hill area, but gravity results indicated that a basement ridge may exist in this same area. The seismic results indicate a sedimentary thickness of at least 17,000 ft between Wandagee Hill and Middalya and possibly 24,000 ft thickness to the east of Middalya. Although no useful information was obtained in the immediate vicinity of Wandagee Hill, extrapolation of results from farther east, suggests that the basement may be as shallow as 6000 ft just west of Wandagee Hill. This would confirm the interpretation of the gravity results at this location. The seismic cross-section shows that there may be a large elevation of the basement over a region about 20 miles west of Middalya between Shot-points 90 and 113. Although there is no direct evidence of this in the gravity results, it may be related to faulting, particularly a fault four miles east of Middalya that is indicated both by surface geology and by gravity results.

  • A seismic velocity survey of the APM Development Pty Limited No. 1 bore at Rosedale, Victoria, was made by the Geophysical Branch of the Bureau on the 3rd May 1960 using a TIC three-component well geophone. Measurements were taken with the geophone suspended in the well at selected intervals down to 5500 ft. It was apparent that signals reached the geophone by transmission along the cable by which it was suspended, and these interfered with the signals reaching the geophone along a path directly through the ground. This made interpretation difficult; however, by careful inspection of both the vertical and horizontal components of the signals received by the geophone at each depth, an interpretation has been made that yields a series of velocity/depth determinations. The average vertical velocity increases from 5000 ft/sec at the surface to 8930 ft/sec at a depth of 5500 ft. The average velocity in the Tertiary (0-2159 ft below datum) was computed to be 6420 ft/sec; the -werage velocity in the Mesozoic rocks penetrated (2159-5314 ft below datum) was 12,180 ft/sec. Two reflection spreads laid out and recorded in the vicinity of the bore showed the presence of reflectors at depths estimated to be in excess of 7700ft.