Annual report for period ending 16-09-1991 on EL 6810 (Bullo River)

Abstract

The licence was examined in a 4 phase work programme, which has shown that the region contains chromite, garnet, diamond, and particulate gold. Initially, 140 stream sediment samples were collected with 12 samples returning positive results (12 chromites and 1 diamond). In the second phase, 66 samples were collected over TM and airphoto anomalies, and to follow up some of the earlier positives. 11 samples returned positive results of mainly garnets and some chromites. The third phase of sampling included follow up sampling for garnet and chromite. All garnet follow up samples were negative with respect to garnet. 184 infill samples were also collected which produced 10 positive results of chromites and 1 diamond. In the final phase 239 follow up samples were collected, which yielded 10 positive results. Traverse sampling within the Moonlight valley Tillite suggests that most, if not all the chromites found within the relinquished area originate from this unit, as would appear to be the case for the particulate gold. Follow-up sampling of the diamonds proved inconclusive. Surface features indicate that the diamonds most probably have spent some time in a secondary sedimentary host. The garnet recovered was not of high interest, but as it was not repeated in follow-up sampling, its presence remains unexplained. It appears very unlikely that a primary diamondiferous source exists in the relinquished area.