Ochre Mine EL 416, Annual report year ending 27-6-1977

Abstract

Surveying-Buxton, Tuder and Waugh of Sydney, N.S.W., completed an extensive tellurometric and geodimeter survey along the eastern margin of the Bonaparte Basin. The survey was designed to tie together the major areas of investigation with the National Grid. One of the baselines traverses the south-eastern corner of the EL and the seismic lines SNBC 5 and SNBC 6 were surveyed in. RESULTS AND CONCLUSIONS-The results of exploration on EL 416 during the 1976 - 1977 year of tenure are not completely clear. Preliminary seismic refraction studies have shown several faults and the velocities of several units, although the interpretation is not yet complete. The position of the contact between the shale/siltstone unit and the underlying sandy carbonates is not very clear.On the other hand the drilling of NBO 1002 identified the contact at about 142m., with a depth of 145m, (gamma log). The litholog of NBO 1002 demonstrates the contact, although the basal units of the sand silt facies have some carbonate horizons and the elastic horizons generally have a carbonate cement. No visible mineralisation was found at or near this contact, and indeed routine check assays of the percussion precollars demonstrates the extremely low values encountered a Results of the investigations during the 1976 - 1977 dry seasons, although not yet complete (seismic refraction interpretation), do not indicate any great potential. The contact between the shale siltstone unit and the underlying sandy carbonate has no associated mineralisation in EL 416.