During late 1951 and early 1952 the Bureau, while searching for open-cut coal in New South Wales, prospected the Big Ben and Donaldson's Seams in the Bloomfield Area which is 3.5 miles south of East Maitland. Drilling involving 21 holes and totalling about 2400 ft. revealed that although the actual coal of the seams was quite good in parts, the seams themselves were subject to marked bending, thinning, and splitting. This not only severely limits open-cut prospects to small areas but will make mining difficult. In the contiguous East Bloomfield, Stoney Pinch and Thornton Areas an additional 16 holes with a total footage of 2,250 feet were drilled and indicated that the seams were characterised by the same rapid variation and offer no better possibilities than the main Bloomfield Area. Operations, including mining, coal analyses, logging, and surveying are discussed. Bore logs and the results of coal sample analyses are appended to this report.

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.

The occurrence of radioactive minerals with cobaltiferous deposits in the Carcoar area has been known since 1894, but until recently they have not received much attention. The present geological survey has been carried out following the discovery of three rather significant radioactive anomalies in the north-eastern part of the mined area, during radiometric surveys in 1950 and 1951. The geological survey has shown that the cobaltiferous-uranium deposits occur in strong north-south shears in an area of Silurian slates and volcanic rocks intruded by diorite sills and dykes, close to the south-eastern boundary of a large mass of hornblende diorite. Opportunities occur for the discovery of other uranium deposits in parallel shears outside the area, in which radioactive anomalies have already been found. This report gives a detailed account of the geological survey. Geology, geological structure, the workings, deposits, and mineralization are discussed, and recommendations are made for future testing and surveying of the area.

Prospectors J.C. Paul and T.C. Ash claimed to have discovered wolfram near Lake Koolymilka in the area reserved for the Long Range Weapons project. The general geology and working of the area are briefly outlined in this report, and it is shown that no wolfram or any other minerals of economic importance are present.

The Cobar field was visited during the period 18th to 24th July, mainly in connection with the exploration programme which is taking place in that area. During this visit, however, some information was obtained concerning the operations of the mines controlled by New Occidental Gold Mines, N.L., which company is being assisted financially by the Commonwealth. Estimated operational costs, grade, and production figures are given. The development, exploration, and future of the field are discussed.

The Treasure Mine, Hatches Creek, is believed to have been discovered in 1914 and has been one of the most consistent producers of wolfram to the present time. This report gives an account of the economic geology of the mine. The ore type, reefs and workings, ore localization, and ore reserves are described.

This report arises from an application by Tableland Tin Dredging, N.L. that tin mining be exempt, like gold mining, from taxation. A detailed examination was made of the tin-mining industry, the results of which are attached to the Report: Appendix I outlines the economic position of the Australian tin industry, and Appendix II summarises the positions of the individual mines. Since the application was first submitted, amendments to the Act have considerably improved the taxation position of mining companies. During the investigation the conclusion emerged that, notwithstanding the recent decided improvements in taxation as applied to mining, some further improvements seemed desirable. Since it was found inadvisable, on grounds of economics policy, to make a special case for the tin industry, proposals were put forward for the mining industry as a whole, using data collected from various mines as particular examples of the effects of taxation.

This report was prepared by the Mineral Economics Section. Part 1 deals with the production of opal and includes sections on the history and present operations in the industry, production and overseas trade statistics, and the types of mining tenures at present available to opal miners. The fields at present being worked are described and the factors which affect production are discussed. Part 2 deals with the marketing of opal and includes sections on the cutting and preparation of stone, markets at home and abroad, and the various factors affecting trade. A number of proposals for improving trade and trading conditions generally are discussed, and the report concludes with a list of references in literature, two graphs showing the value of opal produced in each State and the whole of Australia, from 1890 to 1947, and a map of Australia showing localities mentioned in the text.

The Great Cobar ore deposit was discovered in 1870. Production commenced in 1871 and since that date mining at Cobar has been more or less continuous. The field has produced copper, gold, and silver to the value of approximately £A27,000,000. Cobar has been the most important producer of copper in New South Wales, and in recent years, has also been the most important gold-mining centre. The Zinc Corporation Limited is carrying out, with the aid of the Bureau, an extensive geological and geophysical examination of the area, with the hope of finding other orebodies. The Bureau itself has extended geological mapping over an area of approximately 2,000 square miles in the Cobar-Nymagee-Canbelego district with the ultimate aim of discovering other ore deposits, or even fields of the Cobar type. In the Nymagee district, North Broken Hill Limited is also carrying out, in co-operation with the Bureau, an extensive exploration programme. The history, production, reserves and prospects of the New Occidental, Chesney, and New Cobar mines are discussed in this report.

The scientific search for ore in Australia is still in an early stage of development, because, until recently, a sufficient supply of metals was available from concentrations readily detectable by ordinary prospecting methods. Now the whole mineral supply position is changing and the rate of discovery of new deposits by prospectors in the present century had been quite discouraging. The Australian Government and the Australian mineral industry have recognised the need for mineral exploration both to supply home requirements and to assist in overcoming world shortages. An overview of the situation is presented in this report, which outlines the problem and the corrective reforms and activities undertaken by the state and federal governments, and mining companies, to promote mineral exploration. A summary is given of the exploration and ore-finding work undertaken by mining companies and government agencies between 1930 and 1949.