Final report on EL 1450 Ringwood Copper Prospect

Abstract

The licence areas were granted on the 8th August, 1978. EL. 1450 was reduced in August 1979 and EL 1451 was simultaneously relinquished. The licence areas are located in the Hale River 1:250,000 Sheet area. EL 1450 includes an area of Arunta Complex (basement), which is overlain to the southwest by Upper Proterozoic - Palaeozoic formations of the Amadeus Basin sequence, including the Upper Palaeozoic Brewer Conglomerate. A fine grained facies of the Conglomerate is host to uranium mineralisation in an area south of Alice Springs. Minor copper mineralisation occurs within a shale unit of the Upper Proterozoic Areyonga Formation , in the central part of the licence area, (Ringwood Copper Prospect). Minor lead mineral isation has also been discovered, approximately eight miles to the west. Both prospects have been tested by drilling with discouraging results. EL 1451 consists exclusively of outcrops of the Upper Palaeozoic Brewer Conglomerate. Fieldwork in 1978 was limited to aerial reconnaissance employing a spectrometer mounted in a helicopter. This work indicated that the greater part of the Brewer Conglomerate in the licence areas, consists of the unprospective coarse grained facies. Fieldwork in 1979 has been confined to EL. 1450 and consisted of reconnaissance mapping, sampling and scintillometer surveying of the Arunta

basement/Amadeus Basin unconformity, down the hole ganiiia logging of four water bores and a comprehensive review of all data relating to previous mineral exploration work in the licence area. Results are discouraging. Maximum scintillometer counts from the unconformity survey were obtained from outcrops of grir gneiss (RS 11-260-270 cps), a sample of which assayed 20 ppm uranium and 60 ppm thorium. Cuttings of granite-gneiss from Brigadier Bore assayed 20 ppm uranium and 1000 ppm thorium. Hematitic conglomerate and sandstone outcrops from the -Amadeus Basin unconformity Quartzite), showed only background counts (80-120 cps). Highest uranium and thorium were obtained from RS-1 (10 ppm uranium and 45 ppm thorium). Background counts and analytical values were obtained from the bore hole gamma logging program. The relatively high counts at Brigadier Bore can be explained in terms of thorium enrichment. The highest uranium value from bore waters was obtained from Phillipson No. 6.- 22 ppb. The creek sediment results also indicated background values. One rock sample (RS-4) described in thin section as a greisenised pegmatite, indicates there maybe some potential for tiri/tungsten/ molybdenum mineralisation.The data review indicated that the base metal mineralisation, although extensive is of very low grade and limited thickness (less than 10 feet) Scintillometer scanning of drillcore from the Ringwood Copper Prospect showed only background readings.