Year 3 Annual report for EL 9725 and EL 10136, Hammer Hill project

Abstract

A detailed review of the past exploration in exploration licences 9725 and 10136 has been completed by Andrew Drummond and Associates. The review has indicated that there is the potential to find several types of mineral deposits in the licence area. Arafura's primary interest lies in nickel-chrome mineralisation associated with the Hammer Hill ultramafic intrusive or rare earth elements (REE) associated with barite-apatite veins at the Holstein's prospect. A short field trip has been made to the two deposits and a limited number of samples were collected from each. The visit to the Hammer Hill prospect has tended to down grade the immediate potential of the area. The rock chip samples collected contain anomalous amounts of nickel and chromium however the observations made on site suggest the distribution of ultramafic rock is fairly restricted. Two exploration models were considered, a lateritic accumulation and a primary sulphide deposit associated with a layered ultramafic intrusive. The geochemical analysis and petrology completed on the Hammer Hill samples has confirmed the exposure is a highly weathered remanent of metamorphosed ultramafic rock which is anomalous in chromium and nickel. Microprobe analysis indicates that the elemental ratios are similar to those found in other ultramafic Ni-Cu deposits. The visit to the Holstein's REE prospect has produced similar results as the visit to Hammer Hill. A series of fairly thin dykes containing elevated REE's were located and their compositions noted in the field have been confirmed by geochemical assay, microscopic mineral identification and electron microprobe analysis. The samples from Holstein's are geochemically anomalous in Cerium, Lanthanum and Thorium. The petrology report describes a complex mineralogy containing primary, replacement and metamorphic mineral over prints. Barite and apatite appear to be the important primary host mineral phases. A group of discrete magnetic lows were investigated at West Gimlet but no indication of economic mineralisation was observed. A foot traverse was completed over the anomalies which lie in a broad depression surrounded by hills made of felsic to mafic gneiss and very coarse grained pegmatitic granite.