1951 Report on Willeroo Native Copper Prospect

Abstract

In July 1951, Mr. H. Brennan of Maranboy was granted a reservation of 25 square miles for three months over a native copper prospect on Willeroo station. Mr. Tom Fisher of Manbulloo station via Katherine and manager of Willeroo, discovered the prospect 10 or 12 years ago and collected eight pack saddles of native copper (No. 1 Locality) in the belief that the metal was gold, but lost interest when it was identified. I arrived at the prospect late in the afternoon of Wednesday, August 29th, and departed at midday Friday, 31st. At the time Mr. H. Brennan and two black boys were camped at Campbell's Springs and after spending several days prospecting, had found No. 2 Locality, Native copper, apparently the result of epithermal hydrothermal mineralization associated with lower Cambrian volcanic activity, occurs near the contact of a basaltic lava formation with overlying sandstone. Veining and joint filling is the mode of emplacement and folding may play a part in localisation of the copper. Although large nuggets of copper occur (reported up to 10 lbs) in two localities a mile apart there is no evidence to suggest that the average grade of metal in the lava is high enough to warrant a mining operation. Testing by- diamond drill would not be practicable owing to the apparent highly irregular mode of deposition. Regional mapping from air photographs would help greatly in the understanding of the story of the mineralization, but this could best be left to the Bureau of Mineral Resources.