Annual report for AP 2451, period ending 24-11-1971

Abstract

This area is situated some forty miles southwest of Tennant Creek. Although the area was apparently devoid of outcrop, the company considered that Warramunga sediments might occur close to the surface and therefore considered it prospective for Tennant Creek type mineralisation. Encouragement to this hypothesis was given by a broad zone of aeromagnetic anomalies revealed by the high level BMR survey. During the previous year a contract was let to GRD for a detailed aeromagnetic survey. However, that company had difficulties with their Doppler navigational system which we considered essential for accurate flying in this type of country, so the flying was not commenced until December 1970. The preliminary aeromagnetic results were eventually received in March. These results were considered very promising as some of the anomalies appear similar to those at Tennant Creek. A ground inspection of the area was then carried out. No outcrop was located in the vicinity of the anomalies. The area is semi-desert and it was found impossible to utilize air photos to locate the anomalies. It was realised that sophisticated equipment would be required to locate the anomalies on the ground so that a carefully planned follow-up survey would be required. Detailed interpretation of the aeromagnetic results indicated depths in excess of 300 feet which is in accordance with oxidising conditions for ironstone bodies at Tennant Creek. These results and subsequent discussions with Geopeko Ltd. were sufficiently encouraging for a ground survey to be carried out. Seven anomalies were investigated; one in detail which involved about 40 kilometers of ground traversing. The interpretation of these results was not carried out during the period of this report. During the latter part of this period, negotiations were made with Geopeko for a joint venture. Although successful, they were not finalised in this period. Expenditure for the year was $10,120. This amount does not include the cost of the follow-up ground survey.