Annual report on EL 2657, year ending 14/06/1983.

Abstract

A total of 50 samples, being 20 kg each of sieved -4mm drainage material were collected from creeks within or directly flowing from and closely adjacent to EL 2657. Each sample was collected from a selected trap site, that is, a part of the creek where heavy minerals are more abundant than in the creek as a whole. Partly because of this and partly because creeks in the area contain very high levels of heavy minerals derived from the garnetiferous, hornblende bearing gnelsses of the region, processing of the samples was extremely time consuming. Because some of the important diamond indicator minerals have similar physical properties to the common metamorphic garnets of the region (which comprised to 80% of the weight of the samples) it was not possible to machine stream the unwanted garnets away and produce a small concentrate. Consequently, assessment, which is a visual grain by grain inspection supplemented by A.E.M. analysis of selected grains, proceeded at a glacial pace and the attendant costs as reported here are unusually high.