Presentation made to the Second US Geological Survey Conference on Reserve Growth. Discussed results of reserve growth study undertaken at Geoscience Australia.

The Leigh Creek Coalfield is approximately 350 miles north of Adelaide. Coal seams of economic importance are known to occur in two basins about 5 miles apart. Immediately to the north of the known coal basins is an area of some hundred or more square miles, much of which is covered by a thin layer of rocks younger than the coal measures. Other coal basins could exist beneath this cover, and it is considered necessary to the sound development of the coalfield as a whole, that the prospecting of this area should be completed at an early date. The present survey was undertaken at the request of the South Australian Government and was carried out during October, November and December, 1947. The report is a preliminary one since the analysis of the results is not complete. However, sufficient work has been done to make possible the selection of sites for test drill holes. The geology of the area, geophysical method and application, results, interpretation, and testing are discussed in this report. The results of the gravimetric survey are shown on an accompanying plan.

Approximately fifteen shafts were sunk near the eastern end of the Portion to depths of about 30 feet or more. The shafts were sunk from positions along the boundaries of a right-angled triangle with the east-west zero line for base, the 200E meridian for perpendicular, and the hypotenuse formed by the diagonal from 00/600W to 800N/200E. Two or three shafts have been sunk outside the triangle and none near the centre. This work has served to test thoroughly an area of not less than 400,000 square feet, equivalent to about 25,000 tons per vertical foot. The results of the work to date are discussed in this report.

A visit was made to inspect the limestone and dolomite deposits at Cow Flat and Walls Siding. An overview of the working of these deposits, which includes details of the leases, production, prices, plant operations, future developments, and the present positions of the owner companies, is given in this report.

This map shows Western Australian and Commonwealth fishing closures, marine conservation areas and maritime boundaries for the area from Esperance to the South Australian border. It has been produced for the National Oceans Office.

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.

Brief descriptions and estimates of the size and grade of the more important known uranium deposits in various parts of the world.

The Blue Spec Mine, Nullagine, was visited from 20th to 24th September, 1947. An inspection was made of the mine. No. 3 level (depth 450 feet) was mapped and the antimony-gold occurrences on lease 196, and on the property known as "Blacks", were also briefly inspected. The present position regarding water supply was investigated and recommendations made. The ore reserves, workings, economic considerations, and water supply are discussed in this report.

Bauxite deposits on Rosedale, Meadowbank and Riccarton Estates at Campbell Town were tested by shaft-sinking and boring during November and December 1946. Earlier than this the Tasmanian Mines Department had sunk a number of shafts on the deposits, mainly at widely spaced intervals. The work undertaken chiefly consisted of testing between the shafts sunk by the Mines Department so that the interval between the points tested was reduced to 200 feet or less. A few of the old shafts were cleaned out and resampled. The results of the tests at each estate are discussed in this report.

Bauxite deposits on Rosedale, Meadowbank and Riccarton Estates at Campbell Town were tested by shaft sinking and boring during November, and December 1946. Earlier than this the Tasmanian Mines Department has sunk a number of shafts on the deposits, mainly at widely spaced intervals. The work undertaken by the Aluminium Commission mainly consisted of testing between the shafts sunk by the Mines Department, so that the interval between the points tested was reduced to 200 feet or less. A few of the old shafts were cleaned out and re-sampled. The results of the tests at each estate are reported on.