Legacy product - no abstract available

The Tennant Creek Mining Field occupies an area extending some 70 miles east and west and 40 miles north and south. Over this area are scattered a large number of small mines and prospects and it is sometimes difficult to bring a field such as this into perspective so as to obtain some idea of its true valuation. The following notes are designed to help in this direction. The output and nature of the orebodies, and the respective positions and productivity of the major deposits, are discussed in this report.

The authors were engaged in geological reconnaissance work in the Fitzroy Crossing - Halls Creek area, during the period 16th August to 23rd September, 1948. The principal object of the investigation was to examine the area covered by the Mt. Ramsay Sheet of the Army Series. Work was extended beyond the limits of this sheet however in order to obtain information with regard to the age relationship of some formations, and a visit was made to the Wolf Creek Meteorite Crater 63 miles south of Halls Creek. During the survey, work was concentrated chiefly in mapping the distribution of rocks and different geological periods, determining their relationships and economic possibilities, and recognising areas warranting more detailed investigations. Accompanying geological plans and aerial photographs are included.

Later in September, 1948, the writer, accompanied by L.C. Noakes and an officer of the Department of Works and Housing, Mr. F.K. Hosking, spent part of a morning examining the rock in Mt. Mugga quarry. The object of the examination was to find whether the rock was suitable for aggregate, as the presence of pyrite had been reported some years ago. A set of representative specimens was collected, and these have been studied microscopically. The geological and petrographic characteristics of the rock specimens are described in this report.

The Lesi structure, situated near the coast of the Gulf of Papua, about 100 miles north-west of Port Moresby, was surveyed by plane table. A full account of this survey work is set down in this report. The general characteristics, physiography, and regional geology of the area are described. A detailed account of the geology of the Lesi structure is given, including descriptions of the lithology, palaeontology, stratigraphy, and geological structure. The structure's relation to adjoining structures and the possibility of oil accumulation are discussed. An extract from a micropalaeontological report, geological plans, and photographs of the area are appended.

Old molybdenite-wolfram-bismuth workings in the Stanthorpe-New England area were tested for radioactivity by means of a Geiger-Muller Counter. This report is intended to furnish some notes on the geology of the areas examined, and only general remarks are given on the results of testing for radio-activity.

This report is a summarised account of an investigation into the heavy mineral content of three bores, put down by the Roma Blocks Oil Company. The positions of the bores and a short account of the geology of the area are given, together with results of the work to date, and an evaluation of the prospects of correlation by petrological means.

At the end of 1945 the area dredged by the Bulolo Gold Dredging Co. Ltd. was 831 hectares. At that time 307 hectares remained to be dredged and of this 227 hectares contained soil which has been shown by soil analysis to be reasonably good. Resoiling would not be practicable on about 70 hectares of this area, as the Company plans to dredge this section twice, first with shallow and then with deep-digging dredges. Similar soil exists on 3-400 hectares classified previously by the Company as marginal ground, but which, since the increase in the Australian price of gold, is now probably quite profitable. This makes the total area that might be suitable for resoiling about 500 hectares compared to 1,281 hectares that either has been dredged or to which for other reasons resoiling is not applicable. Revenue to the Administration from the gold produced at Bulolo is over £1,000 per hectare from royalty alone and as most of the area has now been worked it seems questionable whether resoiling is worth further consideration at this stage. No provision was made for resoiling in the terms of the original mining tenements, but the Company's officials have expressed willingness to co-operate in carrying out the wishes of the administration. It has been considered impracticable now to resoil the areas that have been dredged or to rebuild the existing dredges for mechanical resoiling, but if the Department of Internal Territories considers that the matter should be pursued further, the Company might be asked to consider removing soil from the dredge path by bulldozer or other mechanical means and replacing the soil on the flattened out tailings after the dredge has passed; also to provide details of the economics of carrying out a similar scheme on the areas in which values were previously considered to be marginal.

Legacy product - no abstract available

Geological investigation by the Bureau commenced late in July, 1948, and continued until the end of October of that year. The objects of the survey were to lay the foundation for future detailed studies of the mining field, to study the factors controlling ore localization, to assess the quantity and value of ore exposed to date, and to estimate the potential value of the field. In the search for orebodies, a knowledge of the geological factors can be of great assistance, and it is felt that the information given in this report and in the accompanying plans should be of considerable help in this respect. However, the prospector's methods - loaming, dollying, panning etc. are still quite fundamental to success in a prospecting field such as Tennant Creek and the suggestions made in this report are intended to supplement this type of work. The climate, topography, vegetation, gold production, general geology, and gold deposits of the area are described in this report. Detailed descriptions are given of the individual mines examined to date.