Presentation made to the Second Symposium on Resource Assessment Methodologies organised by the Potential Gas Committee and the US Geological Survey. Discussed methodology used at Geoscience Australia and presented some recent results from the Bonaparte and Browse basins.

In response to a request from Mr. W.H. Williams, Director of Mines, Tasmania, a geological survey was made of the asbestos deposits situated near the tunnel on the Emu Bay railway, 5 miles north-east of Zeehan. A programme of investigation was set out involving a detailed survey of the deposit, prospecting and development work, an assessment of potential fibre grades and ore values, and research into milling practice and market utilization of fibre. The geological survey and related investigation, which are the focus of this report, were concerned mainly with the first three items. Three plates, including a geological map, surface plan, and a plan showing underground workings and effective grades, are attached to this report.

A review of the geochemical processes controlling the distribution of thorium in the Earth's crust and Australia's thorium resources can be downloaded from Geoscience Australia's website. The review is one of the outputs from Geoscience Australia's Onshore Energy Security Program (OESP). It will provide an enhanced understanding for government policy and industry investment decisions of the status and distribution of Australia's thorium resources and their potential as an alternative nuclear fuel source for overseas markets.

The results of the Dampier Sub-basin/Rankin Platform medium term assessment indicate that there is a mean expectation of finding: - 167 million barrels of oil, - 0.4 trillion cubic feet of gas, and, - 26 million barrels of condensate in the next ten to fifteen years. This result is from the medium drilling scenario with a low and a high scenario also generated. Reserves growth over the same timeframe is anticipated to add almost 3 trillion cubic feet of gas and 150 million barrels of oil to previous discoveries. Two assessment units have been identified for this assessment: - a gas assessment unit primarily located on the Rankin Platform, and, - an oil assessment unit located in the Dampier Sub-basin.

Preliminary assessment of core recovered from drill holes Nos. 22, 23, and 24, King Island.

In Australia, coal seams occur in stratified rocks of Permo-Carboniferous, Triassic, Jurassic and Tertiary systems. Black coal occurs in the rocks of the first three systems, and brown coal in the Tertiary. In the Northern Territory, Permo-Carboniferous, Jurassic and Tertiary rocks are present. Coal has been found in the Northern Territory, but none of the occurrences are of commercial importance. The occurrence of coal in the Port Keats - Cliff Head, North and East Coast, and Hale River districts is discussed in this report.

Three widely separated scout holes totalling 566 feet of drilling were drilled to investigate the possibilities of open-cut mining sites on the Australasian Seam immediately to the west and south-west of West Wallsend, a suburb of the city of Newcastle. Only one hole intersected the Australasian Seam. This hole indicated that the seam was much banded and of inferior quality - below present open-cut coal standard. Analyses suggested that it may be possible to mine a section of coal 8 feet 7 inches thick excluding non-coal bands, and that this coal would have an ash content of about 29% and calorific value of 10,000 B.Th.U. per lb. after the exclusion of bands.

This statement has been prepared as a supplement to Summary Report No. 27 - Aluminium and Bauxite - which was issued in 1946. Since that year testing of deposits in Tasmania has been completed and new discoveries of commercial bauxite have been made in northern New South Wales and the Northern Territory. Further exploration in South Gippsland has resulted in minor additions to the proved reserves of Victoria, and the presence of bauxite has been reported in Papua and New Guinea. Exploration of deposits of bauxite on the north coast of the Northern Territory is not complete but sufficient accessible reserves have been proved to change the formerly unfavourable outlook for the aluminium industry now being established in Australia. Re-examination of the formerly known deposits has necessitated recalculation of the stated reserves, and has generally resulted in a reduction of the earlier estimates, but on the other hand a substantial increase has been made for the Tamborine Mountain deposits in Queensland. South Gippsland tonnages have been recalculated and expressed as dry ore so as to be consistent with the statements for other States. Tonnages throughout are long tons (2240 pounds) of dry ore. In the following tables proved reserves are those which have been systematically tested by pits or bores regularly spaced at intervals of not more than 400 feet, and in many cases only 100 feet. Indicated reserves have been tested by more widely or irregularly spaced holes.

This report describes a geophysical test survey made in September 1952, at the request of the Queensland Department of Mines and Mines Exploration Pty. Ltd., over an area measuring 750 feet by 1,000 feet in the Liontown area, about 28 miles south-west of Charters Towers, Queensland. The existence of a lead lode was known, because of its exposure in some inclined shafts, and this test survey was made to determine if the geophysical methods used could locate the exact position of the known lode, the ultimate object being, if the test survey were successful, to extend the investigations over a greater area. Self-potential and electromagnetic methods were used. A fairly strong indication, with an easterly strike, was recorded by the electromagnetic method at a position coinciding with the known lode, but no clear anomaly was recorded there by the self-potential survey. An even stronger electromagnetic anomaly, also with an easterly strike, was recorded about 300 feet south of the known lode, and was continuous from one end of the surveyed area to the other. The only self-potential anomaly of any importance was recorded between the two electromagnetic indications and is probably due to a quartz reef with pyrite mineralisation. The results show that the test was successful, in that the known lead lode was clearly indicated, and it is recommended that the survey be extended over a greater area to determine the full extent of the mineralisation. A target for a diamond drill-hole is also suggested, to determine the cause of the high electrical conductivity in the southern part of the area.

A total of 25 rotary cored holes were drilled by the Bureau in Portion 49, Parish of Wallarah, County Northumberland, 2 miles south of Swansea. Approximately 1400 ft. of "test and define" drilling proved a possible 200,000 tons of coal suitable to be open cut under an average overburden of 6/1 ratio. The initial drilling programme showed a rolling seam. After surveying, further holes were drilled to locate the displacement which is 10 to 15 ft. in the S.W. corner of the area. No other obstacles are known which would hinder immediate working of the area. The lower split of the Wallarah Seam was tested in three holes but was found to be too thin to warrant further prospecting. The geology of the area is discussed in this report, and the results of the drilling programme are shown in the accompanying graphic and bore logs.