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These documents have been scanned by the GA Library. Please refer to the document for contents.

These documents have been scanned by the GA Library. Please refer to the document for contents.

These documents have been scanned by the GA Library. Please refer to the document for contents.

Legacy product - no abstract available

Legacy product - no abstract available

Report on the activities of the administrative and technical sections in the Katherine-Darwin area, to April, 1954. A brief account is given of geological and geophysical operations. The results of prospecting and field work are summarised.

During the 1953 field season geochemical prospecting techniques were employed as an additional tool in the search for ore deposits in the Northern Territory. Areas of particular interest were those at which radio-active minerals had already been discovered or at which radiometric anomalies were being investigated. The work thus included the already proved Rum Jungle field as well as the new prospects at Brodribb, Waterhouse, Edith River, and Coronation Hill. A direct chemical test for uranium in soils was not used, the discovery of the radio-active areas being left to the sensitive ratemeters now in use. The close association between copper and uranium was used to advantage as it is present at many of the uranium prospects in the Northern Territory. It is a logical step to use the geochemical techniques to locate new copper mineralization, and then to carry investigations further by attempting to locate uranium in the vicinity of the copper, particularly in areas covered by deep soils where ratemeters are of no use. A field test for cobalt, a metal often closely associated with both copper and uranium, was developed, but of the many samples tested for this element only one gave a positive test. It is possible that the cobalt, an element which is extremely mobile in the oxidized zone, has been completely leached and dispersed from the radio-active minerals.

A geophysical survey, comprising self-potential and electromagnetic methods, was made during the 1952 and 1953 field seasons at the Labour Victory Copper Mine, about 7 miles north-north-west of the Mt. Elliott Copper Mine, near Selwyn, Northern Queensland. The self-potential survey covered an area of 2,400 feet x 900 feet, but owing to other operational commitments during the 1953 season, the electromagnetic survey was confined to the southern part of the area. The primary object of the work was to determine the extent of the mineralisation associated with the known lode, which strikes north-south through the centre of the surveyed area. The self-potential survey revealed a well-defined anomaly nearly 1,000 feet long, in the northern part of the area. The axis of this anomaly is parallel to, but about 75 feet west of, the known lode. The disused main shaft of the now idle mine is at the southern end of the anomaly, which in this vicinity deviates slightly towards the south-east, i.e. towards the known lode. No workings exist in the area of the indication, and no outcrops were found, the rock formations being hidden for the most part by alluvium. The electromagnetic results confirmed those of the self-potential survey, but the electromagnetic indication extends farther to the south. The results suggest that the indication may be caused by lenticular bodies and that these are disturbed by cross faults. No mineralised deposits were indicated by the electrical results in the southern part of the area. It is recommended that some trenching and geological and geochemical work be done in the area of the strong electrical indication. If the results of the testing show that the indication is not due to graphitic or pyritic schists, it is recommended that a number of diamond drill holes be put down. Suggested locations for five such drill holes are given. If the anomaly is due to ore the geophysical results suggest an ore body of considerable size.

Geophysical surveys of the magnetite deposits of Australian Magnetite Pty. Ltd. at Gulgong were made by the Bureau in 1952 and 1953, and revealed that the Tallawang deposit was the most important one. The present report gives the results of a detailed magnetic survey which was made over this deposit in August, 1953. Results show that three concentrations of very strongly magnetic material exist within the Tallawang deposit. The southern concentration is unlikely to contain considerable reserves beyond those in sight. The central concentration has been partly worked and could yield reserves of ore from the west wall of the quarry. The northern concentration, which has not been worked, could yield limited reserves. It is shown that the deposit, as a whole, pitches northwards. Some exploratory drilling is recommended on each of the three concentrations.