South Alligator Valley stream sediment orientation survey

Abstract

The report describes a stream sediment orientation survey based on 15 samples collected throughout the South Alligator Valley in early 1986, as preparation for surveys over broader regions. Sampling was confined to creeks draining known mineralisation. The drainages from the Coronation Hill, Scinto Plateau, El Sherana, and the Rockhole groups of mines were sampled. The study evaluates gold distribution in various mesh fractions, pan concentrates, and cyanide extractible gold. Cyanide leach gave the most reliable result, and is recommended for future work. Pt and Pd analyses are not recommended in stream sampling, but Pd should be considered in cyanide leach surveys. 5kg of -2mm bed-load sediment should be collected at a spacing of one sample per 2km2. If base metal assays are required, sufficient -80 mesh material should be screened from the sample in the lab.