Annual Report EL 4500 for the period ending 27/12/1986.

Abstract

CEGBEA continued uranium exploration on EL 4500 during the 1986 field season under a joint venture agreement with the title holders, Australian Coal and Gold Holdings Limited. The data from the CEGBEA 1985 airborne survey were computer processed and interpreted. At Uranium Ananaly U4 a detailed Track Etch and ROAC survey showed moderately to strongly anomalous subsurface radon values adjacent to a hill of brecciated Koolpin Formation. Thirty three percussion drill holes were completed to an average depth of 30m. Fresh, moderately to strongly graphitic siltstone was intersected in all drill holes at around 18m depth. Radiometric down the hole logging indicated weakly anomalous radioactivity at the weathering interface. Analyses of cutting samples reported low uranium values indicating that the radioactivity was caused by uranium daughter elements. It is proposed to further investigate the anomaly by diamond drilling during the 1987 field season in an effort to trace the uranium mineralisation which is the source of the radioactive daughter elements and also to test targets outlined by the GEM-8 surveys. Because of the differences in deformation and alteration between the Kombolgie Formation of Western Arnhem Land and the quartzites of the Mount Douglas Outlier and as it is suspected that the Mount Douglas rocks are much older, possibly El Sherana Group equivalents. It is recommended that the quartzites at Mount Douglas be referred to as the 'Mount Douglas Formation'.