Seismic reflection studies in the Perth Basin, between the coast and the Darling Range, 30 miles north of Perth, were conducted in an attempt to derive a suitable recording technique for obtaining reflections when shooting on the Coastal Limestone formation, to investigate geological structure in the basin,and to supplement hydrological studies being madeby the Geological Survey of Western Australia. Experimental work occupying half of the survey period failed to yield a technique for obtaining seismic reflections on the Coastal Limestone, but led to reflections being obtained across the major part of the basin, Record quality with a fairly heavy technique was poor to fair in the western half of the basin off the Coastal Limestone but improved considerably to the east. A complex geological section in the west gave way to a more concordant thick synclinal section in the east, terminated at its eastern end by the Darling Fault. Of interest is an apparent anticlinal reversal of dip in beds lying deeper than 7000 ft,with the reversal axis near the centre of the major gravity 'low' of the basin.

The Vibroseis method of seismic exploration was first introduced into Australia during 1963. In accordance with the programme for accelerated oil search, the Bureau of Mineral Resources employed a Vibroseis seismic party to demonstrate the performance of the method in various problem areas within the Otway and Sydney Basins, the locations of which are indicated on the regional map. The Experimental Vibroseis Seismic Survey was conducted by Seismograph Service Limited. Party 243. on behalf of the Bureau of Mineral Resources, Geology and Geophysics during the period from 11th May to 3rd October, 1964. The broad objective of the survey was to demonstrate the capabilities of the Vibroseis method in selected areas where previous conventional seismic surveys had experienced difficulties in obtaining results and where various seismic problems had been defined. The main aim of the survey was to obtain good quality results rather than a high production rate yielding poorer quality data. However, as a secondary objective, some short production traverses were recorded USing the optimum field technique developed during the course of the survey for comparison e with normal shot hole production techniques.

Some experimental geophysical work was undertaken by the Bureau of Mineral Resources at the Moura Coalfield in Queensland in order to investigate the structure of coal seams which lie within 1000 feet of the surface. The aim of the survey was to evaluate the use of geophysical techniques for locating faults of small displacement. Most of the effort was concentrated on shallow seismic reflection techniques but additional techniques (magnetic, gravity, resistivity, electromagnetic and induced polarization) were used. The whole area of the survey was covered with a close-spaced grid of gravity and magnetic stations. A lesser effort was devoted to resistivity, electromagnetic, and induced polarization methods, the object being to take advantage of the opportunity to tryout these relatively inexpensive methods in the hope that they might give some indications of fault locations. These methods will be evaluated in a separate Record; this one deals- with the results of the seismic work. Encouraging results were obtained from seismic reflection work. The uppermost economic coal seam was mapped to within 300 feet of the surface and areas of faulting could be deduced from time differences and lack of continuity in reflections.

Field tests were conducted on 11 March 1974 in Waiaal Victoria to compare the seismic efficiency of Molanite, TNT, and-Anzite Blue. Ueismic energy p:enerated by equal amounts of each explosive was recorded in identical conditions, and the amplitudes of the refracted and reflected waves were measured and compared. The comparisons indicated that Molanite and Anzite Blue were equally efficient whereas TNT was about 10 percent less efficient. No significant difference was observed in the character of the seismic energy generated by any of the explosives tested.

A deep crustal seismic reflection survey, conducted at Gundary Plains near Canberra, to test a digital seismic recording system, produced additional data for interpretation of seismic refraction profiles in the Lachlan Fold Best. Good reflections were recorded down to the probable Moho, at an estimated depth of 41 km. The intracrustal reflections are characterised by bands of seismic energy, which probably represent velocity transition zones within the crust.

<p>Geoscience Australia conducted a seismic survey in the central Eromanga Basin in Queensland in 1981. This survey was a continuation of the work undertaken in 1980 to investigate the structure, stratigraphy, geological and tectonic evolution, and petroleum potential of the area. The survey obtained 438 km of six-fold Common-Depth-Point seismic reflection data, in the Quilpie Trough and over the Cooper and Thomson Synclines.<p><b>Raw data for this survey are available on request from clientservices@ga.gov.au - Quote eCat# 74971</b>

<p>Geoscience Australia with assistance from the Geological Survey of Queensland conducted a seismic survey in southeast Queensland form April to December 1984. The survey set out to investigate deep structures within the earth's crust and is the first of the Australian Continental Reflection Profiling (ACORP), initiatives to study critical transects of the Australian lithosphere. The survey obtained 798 km of six-fold seismic reflection data over the Westgate Trough, Nebine Ridge, Surat Basin, Kumbarilla Ridge, and Clarence-Moreton Basin.<p><b>Raw data for this survey are available on request from clientservices@ga.gov.au - Quote eCat# 74969</b>

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