Geological Investigations, Golden Dyke Dome NT.

Abstract

The CRAE leases on the west limb of the Golden Dyke Dome were investigated to assess their potential to host economical viable stratabound gold mineralisation associated with banded iron formations. The area was mapped at 1:2500 scale, rock chip sampled and favourable horizons costeaned after a systematic soil sampling prbgramme. Mapping has indicated that the leases contain the favourable iron formations i1 to i5 of the middle Koolpin Formation. The i4 member is host to the mineralisation at the Golden Dyke Mine. The soil sampling outlined two areas worthy of further investigation, Northern Costeans at the Good Shepherd Anticline and Fishers Lode at the Black Rock Flexure. Rock chip and costean sampling of the Northern Costeans area resulted in gold values to 1.5 g/t for i5 and values less than 0.15 g/t for the i1 to i4 members. Fishers Lode (i5) at the Black Rock Flexure assayed up to 6.4 g/t gold but only short stratigraphic lengths are inferred to have this grade. Costeans on this member only assay up to 0.25 g/t gold. The lower banded iron formations, i1 to i4, in this area generally have gold values less than 0.15 g/t but the 13 member grades up to 1.3 g/t gold and the i4 member to 0.8 g/t gold. Samples of the quartz veining in the dolerite and carbonaceous mudstone assay up to 1.17 and 2.85 g/t gold respectively. Therefore anomalous, but uneconomic gold values were obtained from the prospective banded iron formations of the middle Koolpin Formation.