Annual report for EL 26103 Allungra Creek, for period ending 5 February 2010

Abstract

EL 26103 was granted to Matilda Minerals Ltd on 5th February 2008. NuPower subsequently acquired an interest in the tenement on 17 March 2008 through being offered a package of tenements in the Aileron region for joint venture. NuPower was attracted to the Allungra Creek property by its strategic position amongst NuPower's own tenements of the Aileron Project. The oldest rocks are Pre-Cambrian orthogneiss exposed beneath units of the Ngalia Basin in the south. Palaeoproterozoic rocks of the Aileron Metamorphics (Aileron Province Division 1) consisting of pelitic, semi-pelitic, psammitic and calc-silicate gneisses and granulites and rare diopsidic and forsteritic marbles, meta-gabbro, dolerite, amphibolite and mafic granulite crop out in the northern part of the license, north of Allungra Creek. They are intruded by Proterozoic gneissic biotite granite. South of Allungra Creek the Arunta Inlier is stratigraphically unconformably overlain, though, because of thrusting, structurally underlain by Neoproterozoic and early Palaeozoic sediments of the Ngalia Basin. The succession consists of shallow marine and fluvio-glacial clastic, carbonate and evaporitic rocks, overlain by Devonian and Carboniferous fluvial to continental sandstone, greywacke and siltstone. Only the lower units are exposed here in the Hann Range consisting of the Vaughan Springs Quartzite composed of a thickly bedded quartzite and conglomerate and containing the Truer Member consisting of thin bedded fine sandstone siltstone and possible evaporates. Structurally the southern NT forms a 'basin and range' province with Proterozoic and Palaeozoic rocks forming prominent mountain ranges separated by broad valleys. Cainozoic basins of unconsolidated sediments are widespread and well-developed within these intervening topographic depressions. The Allungra tenement lies on the southern margin of the Ti-Tree Basin and includes part of a major east-west trending palaeochannel draining eastwards into the basin. The stratigraphy of the intermontane Cainozoic basins is subdivided into a two-fold stratigraphic succession that broadly corresponds with the observed pattern of Cainozoic edimentation elsewhere in southern Australia comprising a restricted, fluvial palaeochannel dominated Palaeogene succession (Hale Formation) and a more widespread, dominantly lacustrine Neogene succession (Waite Formation). Deposition of these sediments was episodic and punctuated by hiatuses during which prolonged periods of weathering resulted in the formation of well-developed weathered profiles. Three weathering events which affected Arunta igneous and metamorphic basement rocks and the overlying Tertiary succession have been identified. The Waite Formation interfingers with and is conformably overlain by a moderately thick (<60m) succession of oxidised colluvial material shed from the ranges in response to neotectonism during the (?Late) Pliocene, comprising a broadly coarsening upwards alluvial fan succession that can be recognised throughout the region. This unit is informally referred to as the Napperby Formation and comprises oxidised and haematitic, clayey sands, sandy clays and minor conglomerates. Cainozoic sediments are not exposed here but are reported from drill holes. The Napperby Formation is capped by Quaternary alluvial sands and gravels and aeolian sand and red earth that accumulated downslope from the uplifted areas. Basement rocks of the Reynolds, Yalyirimbi and Strangways Ranges contain elevated background levels of uranium and thorium and have been explored for gold, base metals, rare earth elements and uranium and although there are no reported mineral occurrences here the most significant discovery to date in the region is the Nolans REE-U-Th-P near Aileron. In 1972 CRA Exploration Pty Ltd recognised that while these rocks may host primary deposits of uranium they also provide a potential source of uranium for secondary uranium deposits that may have accumulated in flanking Cainozoic basins. Arafura Resources Ltd also recognised the potential of the Cainozoic basins in the Aileron region on the flanks of the uraniferous basement rocks for secondary sandstone-hosted uranium deposits and acquired a number of exploration licenses in the Aileron region. Some of these licenses, and the uranium exploration rights of others were transferred to NuPower during the demerger process from Arafura. NuPower recognized the strategic position of EL 26103 amongst its own Aileron properties and proceeded to gain access to the tenement through the JV with Matilda to explore for uranium. Although the area has been poorly explored for gold and base metals it appears to have never been explored systematically for uranium. The area formed part of the NuPower regional airborne electromagnetic (AEM) surveys in 2007 and 2008 for palaeochannels as hosts for sandstone hosted uranium in Cainozoic sediments and the Geoscience Australia-NTGS Central Arunta Gravity Survey (CAGS) that provided valuable data for the interpretation of basement structures as controls for other styles of mineralisation including gold, rare earths, carbonatites and diamonds. The AEM survey consisted of 159 line kilometers representing <1% of the total survey. It was flown at a nominal survey height of 120m on 1km spaced lines. The AEM survey has identified an important palaeochannel some 25km long trending eastwards through the license area, about 2km wide. The headwaters of the channel drain uranium channel airborne radiometric anomalies in gneisses of the Nolans Dam Metamorphics that may provide a local source for secondary uranium. On review it was considered that the section of channel here represented instead the interfluve between two opposing palaeochannels flowing east and west in opposite directions. This area appears to be shallow, the sediments are thought to be oseidised and therefore this section is now considered unprospective for uranium and has been relinquished. A small deep basin, 5km by 2km in size has been retained in the southeast part of the area for its uranium prospectivity and most of the northern apart has also been retained for its potential to host Nolans Bore-type mineralization in sub-outcropping Boothby Gneiss beneath extensive shallow sand cover.