From 1 - 10 / 190
  • Deep alluvial leads of Recent, Pleistocene, and Tertiary age have been of considerable economic importance in Australian mineral production. Numerous basalt-covered and alluvium-covered auriferous leads have been worked in New South Wales and Victoria, but are quite rare in other states. However, important stanniferous deep leads have been worked at Herberton in North Queensland. Several geophysical methods can be applied to the investigation of alluvium-covered leads, the seismic refraction method being generally the most suitable. In the case of basalt-covered leads the geophysical problem is more difficult, although satisfactory results have been obtained by the magnetic method at Gulgong, New South Wales, and at Herberton. More recently (1948-49) the seismic refraction method has been applied to problems of this nature at Kalgoorlie, Western Australia, and Wellington and Ardlethan in New South Wales. At Kalgoorlie, geological evidence indicates that deep auriferous leads may extend for some distance to the south of the main Kalgoorlie lodes. At the request of the Western Mining Corporation, seismic refraction profiles were obtained along two 7-mile traverses. The first traverse (A) was about 15 miles south of the mines and the second (B) about 2 miles to the south of the "golden mile". The refraction profile revealed two deep channels crossing traverse A and two channels crossing traverse B; the depth to bedrock on both traverses was, 'however, much greater, than anticipated. For some years alluvial gold has been dredged along the banks of the Macquarie River near Wellington, New South Wales. In order to plan the course of the dredge, a considerable amount of advance drilling and sampling has to be done by, the company concerned. It was considered that the seismic method might be employed in order to reduce the amount of test drilling which has to be done. In 1949, the method was tried in this area but it was found to be too costly in this -application, due to the poor transmission qualities of the overburden which necessitated the use of -large charges or the drilling of deep shot holes. However, the limited amount of work which was done did indicate the unexpected presence of deep ground in a part of the area which had not been tested by boring. In the past, small stanniferous lodes have been worked about 6 miles to the north-west of Ardlethan. The geological evidence suggested that alluvial tin, shed from the Bygoo deposits, might be found at shallow depth. The seismic refraction method was used once again, but it was found that the depth to bedrock was much greater than had been anticipated. However, the presence of a deep gutter, running in a north-easterly direction from the old workings, was fairly well established and drilling recommendations were made to the company concerned.

  • Legacy product - no abstract available

  • It appears that this product no longer exists. Copies are not held in the Library, and efforts to locate one externally have also been fruitless. This record will be retained only as proof of existence of the product at some time in the past.

  • A seismic reflection survey was made to the south-west, south and east of the Poole Range Structure, Kimberley Division, W.A. as an extension of a previous seismic survey. The results obtained confirm the surface information and show the existence of an anticlinal structure l the axis of which plunges to the east and whose axial plane probably dips to the south. A total thickness of sediments of the order of 20,000 feet is shown. Some slight evidence of deep faulting down to 10,000 feet was recorded, but is not conclusive. Insufficient evidence was obtained to select a site for a test bore, but further seismic work is not recommended at present.

  • As a contribution towards the assessment of the oil potential of the Canning Basin, the Bureau carried out a seismic survey in July, 1955 along a traverse to the north-west of Lansey's Cross ing in the Kimberley Division of Western Australia. There is a considerable thickness of sedimentary rocks, probably exceeding 20,000 feet, in the nearby Fitzroy Basin, but little is known of the structure of the Canning Basin. The object of the survey was to obtain information on the thickness of the sedimentary rocks in this part of the Basin and on thc geologicul structure of the sedimentary rocks at depth. The results show that near Langey's Crossing the thicknes s of the sedimentary rocks probably exceeds 16,000 feet and may exceed 20,000 feet. The traverse was oblique to the assumed. direction of the axes of the major structure in the basin and results indicate that it crosses the axis of what appears to be a broad syncline of low relief.

  • These documents have been scanned by the GA Library. Please refer to the document for contents.

  • These documents have been scanned by the GA Library. Please refer to the document for contents.

  • These documents have been scanned by the GA Library. Please refer to the document for contents.