Monthly reports on AP 3156 Oorabra, 1971 to 1972

Abstract

An 18 hole drilling programme aggregating some 200o feet was laid out during the month. Two holes aggregating 190 feet were subsequently drilling but this program was terminated due to the summer weather conditions. Both holes intersected quartz-fluorite vein material greater than 5 feet thick. The veins strike to the north-north-west over a distance of 500m. The true widths of the veins are less that 0.5m. Geological mapping and aerial photo compilation of the AP continued on the northern part of the Elyuah range. No mineralisation has been found other than hematite in the south western part of the AP. Recon and geological mapping continued and field traverses were made to obtain an overall view of the stratigraphy. The Jinka granite extends into this area and is transected by quartz veins. To the south these have been known to contain minor amounts of copper. There was also the presence of barite veins many of which are known to be fluorspar veins. More mapping and geochemical sampling to take place. The largest fluorite reef discovered to date strikes 320 deg for a distance of 2.5km and dips 60 deg westerly. Oorabra was granted to Central Pacific Minerals on 21 April for 12 months expiring on 29 March 1972. Plans are in hand to compile appropriate base maps prior to photo geology and geological mapping. During preliminary recon some work in the vacinity of narrow fluorspar veins was carried out. These are known as Narbarloo. Near Narbarloo fluorspar prospects most of the area is covered by alluvium and colluvium overlying lower proterozoic Jinka Granite. The remainder of the area is overlain by Lower Cambrian to Upper Proterozoic sediments including the Oorabra Arkose and siltstone of the Mt Cornish Formation. The siltstone thins out towards the centre of the area where Jinka Granite is overlain unconformably by Oorabra Arkose. Here, the Arkose contains small barite lenses up to 10 meteres in length. These are very similar to those found in the Jinka Fluorspar reefs except for the absence of quartz.