EL 7190, partial relinquishment report, March 1993

Abstract

Exploration for diamonds, base metals and gold was carried out over the relinquished portion of EL 7190. Thematic Mapper imagery and air photos were examined prior to the commencement of fieldwork. No anomalous features thought indicative of ultramafic intrusives were observed. Reconnaissance heavy mineral stream sediment sampling for diamonds was completed, and possible kimberlitic indicator minerals, mainly being spinels, were obtained from a number of samples draining breakaways of Cretaceous rocks. Infill samples were collected, which confirmed the anomalous nature of a number of catchments. Rare kimberlitic compositions were obtained, but results were not encouraging enough to warrant further diamond exploration. The indicator minerals are of low interest and probably being derived from a secondary source of Cretaceous sediments. It is most unlikely that the are derived from a proximal diamondiferous ultramafic source rock. The geochemical data was reviewed, but no significantly anomalous results are present within the relinquished area.