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  • An enquiry has come from the Melbourne University Ore-Dressing Laboratory concerning the mineralogy of ores from Nos. 1 and 2 orebodies at Rye Park. Mr. K. S. Blaskett, Principal Research Officer at the Laboratory, has done treatment tests on ore from the No. 1 orebody, but is uncertain as to whether the sample investigated is typical of the ore as a whole. Sullivan and Dallwitz (1952) suggested that scheelite is more abundant than wolfram in the ore, but Mr. Blaskett found that the principal tungsten mineral is wolfram; evidence for this was obtained during ore treatment tests, and was confirmed by mineragraphic work. According to the geological report, fluorite is stated to be abundant, but very little fluorite was found in the ore treated in the Laboratory. As the bulk of the ore at Rye Park is in the No. 2 orebody, the question has arisen whether this ore is appreciably different from the sample tested. Differences in mineral association, grain-size, etc., may be very important in ore treatment. The following report describes in a general way what is known at present about the minerals and problems in which Mr. Blaskett is interested.

  • An area of about 12,000 square miles was mapped in the field seasons 1950-51. It contains four Pre-Cambrian rock groups ranging from Archaeozoic to Uppermost Proterozoic. The main groups in the area, the Mt. Isa and Lawn Hill Groups, are shallow-water geosynclinal sediments involved in a Proterozoic orogeny which resulted in fairly intensive folding along dominantly north-south axes, together with much faulting. The geological features discussed in this report include physiography, topography, stratigraphy, igneous activity, structure, mineral deposits and water supply.

  • A total of 22 "testing and defining" rotary cored drill holes were drilled by the Bureau and J. McD. Royle Ltd., contractor to the Bureau, during the prospecting for reserves of open-cut coal in the Tomago Stage of the Upper Coal Measures near Buchanan. These 22 holes involved 3640 ft. of drilling and indicated possible reserves of 4,200,000 tons of coal suitable for mining by underground and open cut methods. The geology of the area, and the operations carried out, including mining, logging, sampling, analysis, and surveying, are discussed. The results of the drilling programme are shown in the accompanying maps, and graphic and bore logs.

  • The Australian Antarctic Expedition 1911-14 established four absolute magnetic stations, namely Stations A, B, C and D. Two subsequent stations, Stations E and F, came into operation in 1950 and 1952 respectively. Because absolute magnetic observations had been made at different stations is was essential that the differences in the magnetic elements between the various stations be determined so that all data could be reduced to a common point. The observations were carried out during the period 31st March to 6th April 1952, whilst the Australian National Antarctic Research Expeditions relief operations were in progress.

  • Samples from three bores in the Great Artesian Basin in Northern New South Wales were submitted by the Water Conservation and Irrigation Commission of New South Wales for micropalaeontological examination. These bores are: Bore No. 8256, M.E. Howe, "Retreat", Dubbo, Bore No. 8259, L. Fitzell, "Marathon", Dubbo, [and] Bore No. 8264, E.W. Robinson, "Womparley", Bourke. The results of the detailed examination of the samples are given below.

  • With Australia's postwar immigration programme and the increased demand for food supplies, an expansion of Australia's rural industries is of primary importance, both to increase domestic food supplies and to obtain foreign exchange by export of primary produce. For such a development, the rainfall, surface and underground water resources are the factors of prime importance. In West Australia the difficulties met in finding water for farming purposes prevents rational development of many rural areas. Also, in some places town water supplies are insufficient or the water is saline. Water resources may be classified as follow: rain water from tanks or dams, water from bores or wells, water from old mine shafts (in mining districts), water from springs, [and] water from rivers. The present investigations are not concerned with the last two types of water supply. The following aims were set. 1. To test several types of instruments, to discover their limitations and ranges and the optimum conditions for their operations. 2. To estimate the accuracy of depth determination to discontinuities which might be related to the geology. 3. To investigate the possibility of distinguishing the nature of the discontinuities, for instance, decomposed granite, fresh granite, ground water level, etc., and the possibility of estimating whether ground water is fresh, brackish or saline. The tests areas were selected in the belief that sufficient bore information would be available to serve as controls. However, except at Austin Downs, near Cue, and at Big Bell, the bore information was generally insufficient, vague and unreliable. With the exceptions mentioned above, adequate records had not been kept. The purpose of the geophysical survey was not primarily to search for areas with favourable ground water occurrences but to test the resistivity method in areas where information on the occurrence of ground water was available from existing wells and bores. The order in which the tests are described in the report is: Wubin, Cue, Big Bell, Lake Grace and Kulkin.

  • In the search for deposits of radioactive minerals in Australia the area of the Barrier Ranges appears especially worthy of investigation on geological grounds because it is composed of highly mineralised pre-Cambrian rocks. Mines in this area comprise the major producing mines along the main Broken Hill lode, one developed mine of less importance (the Pinnacles), and a number of small silver, lead and copper mines scattered over the surrounding district. The present report deals with the results of a reconnaissance radio-active survey performed by the Geophysical Section of the Bureau during July and August, 1950. The work was confined to the smaller mines, attention being directed, in the first instance to the mines from which radio-active museum specimens were stated to have come. At each mine the following tests were performed: tests on dumps and residues to discover whether any quantity of stone carrying a significant content of radio-active minerals had been broken during mining operations, tests on accessible exposed faces, and tests on rocks surrounding the mines. The tests were made with portable Geiger-Mueller rate-meters. Readings taken are quoted as multiples of background count, which has been considered as a constant characteristic of the instruments, rather than as the general reading obtained on country rock in the area. In most areas these methods of defining background would lead to the same result. As mentioned later, however, in the Broken Hill area this is not the case. Generally, the schists and gneisses on this field are definitely radio-active, and a true background reading, indicative of the complete absence of radio-active minerals, is obtained only on basic rocks. A reconnaissance survey was also made over the Euriowie tin field. Tests were also made around felspar quarries at Egebeck.

  • A brief geological examination of this deposit was made by the writer and D.N. Smith between 18th and 20th June, 1952. The deposit had been previously examined in 1951 by J. Daly of the Geophysical Section, Bureau of Mineral Resources, and by J.C. Lloyd of the N.S.W. Mines Department and the results of their investigation were available for reference. The radioactive area examined during the present investigation was an area of about 1/4 square mile of the volcanic flow in the north-eastern corner of portion 39. Samples of the quartz veinlets and of the volcanic rocks were collected, and tests carried out with the Laboratory Geiger counter in Canberra indicate that both are radioactive and that the radioactivity is slightly greater in the sample from the quartz veinlets.

  • For the evaluation of the petroleum prospects of a sedimentary basin, the following factors are generally considered. Lithology, mode of deposition, thickness of the sediments contained in the basin, source and reservoir rocks. Facies of the sediments, changes in facies and the trends of such facies changes. Relationship of the various formations to each other - conformity, disconformity, unconformity, regressive and transgressive overlap, erosional gaps and their significance structurally and for accumulation. Direct or indirect evidence for the presence of oil - seepages, traces or showings of bitumen, oil and/or gas existing bores, bituminous character of some of the stratigraphic members. Tectonics - folding (single phase, multiple phase), faulting, tectonic history and its bearing on migration and accumulation of oil. Types of tectonic traps, and stratigraphic traps in relation to folding and faulting (sandy facies near basement uplift, reef formation on crests of rising anticlines, sandy facies in connection with ancient fault lines). Some of these criteria can be applied to the North-West and the Fitzroy Basins, but it is realized that the information available is not complete enough yet to fully discuss all aspects involved. On the other hand it is felt that, at this stage, a brief review of the results already obtained can greatly assist in an outline of a future programme. It will be seen that much emphasis is laid on geophysical work i.e. gravity investigations for the regional aspect of the problem - the configuration of the basins - and seismic investigations of structures which are selected for deep testing. In our opinion the results obtained so far in the North-West Basin, by both types of geophysical work, have clearly demonstrated the soundness of this way of approach

  • The distribution of marine Tertiary rocks in Australia is restricted to the western and southern coastal areas of the continent. The rocks represented are of Paleocene, Eocene, Miocene and Pliocene ages. Considerable material has been collected in stratigraphic sequence from many Tertiary localities in recent years and the detailed examination of the foraminiferal content of the rocks has yielded many startling discoveries.