Annual report on exploration for EL 2890 Jervois from 28-10-1981 to 27-10-1982

Abstract

The first part of the exploration programme was a literature search at the Department of 'Mines and Energy both in Alice Springs and Darwin. This search covered the eastern half of the Arunta Block with particular reference to the Huckitta 1:250,000 sheet. The licence area has formed part of a regional geological mapping programme which covered the southern half of the Huckitta 1:250,000 sheet. The mapping was undertaken at a scale of 1:50,000 using government produced RC 9 photographs. The EL is located toward the eastern part of the Arunta complex, a belt of Lower to Middle Proterozoic rocks that spreads in a wedge across the sourthern part of the Northern Territory, narrowing towards the east. Within the licence area the geology is composed of remnants of Lower Proterozoic metasediments composed of schists and gneisses, the latter varying in composition from quartzo-felspathic gneisses to those composed of calc-silicates. The metasedments have been enveloped by the intrusion of Middle Proterozic granites. Subsequent erosion has denuded the area leaving the metasediments present as only roof pendants within the granites. A large proportion of the area is covered by Quaternary wind blown sand which masks much of the underlying basement. After studying the Molyhil deposit it was decided to undertake a detailed airborne magnetic survey over selected areas of the tenure held by the Peko-Petrocarb joint venture. EL 2890 formed part of one such area. The survey was flown with a line spacing of 150m, at a mean terrain clearance of 80m with an average sample interval of 45m. The preliminary data from this survey was produced at 1: 10,000 and 1: 50,000 ,the latter scale is to coincide with the regional mapping preliminary observations of the results from the magnetic survey give no obvious indications of anomalies caused by Molyhil type bodies. However, to date, comparatively little follow up work has been undertaken and it's too early to dismiss the area. The airborne survey has provided evidence in the form of a trough of magnetic lows to suggest a nearly east-west fault entering the licence area from the west. It is likely that this structure represents a possible eastward continuation of the Delny-Mount Sainthill fault zone.