Final Report for EL 10215 Jervois Project

Abstract

EL 10215 was granted to Arafura Resources on 6 December 2001 and ceased on 6 November 2012. The tenement ceased due to the granting of replacement EL 29701 which combines EL 10215 and EL 26812. The geology of Jervois project area is mostly greenschist-amphibolite facies Palaeoproterozoic metamorphic and igneous rocks of the Aileron Province, Arunta Region with the unconformably overlying Neoproterozoic-Palaeozoic sedimentary units of the Georgina Basin outcropping in the northern parts. The region has potential to host numerous mineralisation styles including those akin to the Jervois Mineral Field, including metamorphosed polymetallic base-metal deposits as well as W and Mo skarn and vein-style deposits. Arafura's exploration efforts largely focussed on assessing the Fe-Ti-V resources of the Unca prospects within the Palaeoproterozoic Attutra Metagabbro. The Unca magnetite-hosted Fe-Ti-V prospects occur as a number of discrete magnetic bodies and are regarded as metamorphosed orthomagmatic deposits. Outcropping magnetite mineralisation occurs as cm-dm layers or as larger massive coarse grained bodies. Exploration activities included reconnaissance mapping and surface sampling, the acquisition of a detailed airborne geophysical survey to guide undercover exploration and two RC drilling campaigns with associated assaying and DTR test work. Arafura also sponsored a BSc Hons project which involved potential field modelling of detailed gravity and a ground magnetic survey data collected over a number of magnetic targets concentrating on the Casper magnetic anomaly. A total of 5,774 metres of RC drilling was completed in 60 vertical or inclined holes with hole depths varying from 25-120 metres. One of these shallow holes was drilled to supply water for the 2008 base camp. All other holes were drilled to test the near surface Fe-V mineralisation potential of various magnetic anomalies. A number of named magnetic anomalies have been more extensively drilled; these include the Casper, Coco, and Misty anomalies. Exploration RC drilling demonstrated significant Fe-V grades with moderate to good Fe-V recovery in processed magnetite concentrates from mineralised drill intercepts that are up to at least 77 metres thick in the more massive magnetite-rich zones. At Casper, a number of composited RC assay samples approach a maximum of 1.1% V2O5 but more commonly assay samples contain 0.3-0.8% V2O5. Laboratory testing using 100% passing 75micro typically shows DTR concentrate grades of 61-69% Fe and 1-2% V2O5. The most strongly mineralised assay samples are from Casper and yield DTR concentrates containing up to 2.5% V2O5. As shown in the table below, drilling results from the Coco and Misty magnetic anomalies yield slightly lower V2O5 and higher Fe grades than Casper. A number of the 2006 RC drilling program magnetic targets yielded lower grade DTR concentrates with <1% V2O5 and have not been evaluated further. It is suspected that the Unca Fe-V prospects may eventually be considered for economic development. This is because the Fe-V grades of the magnetite-rich mineralisation at Unca and its DTR concentrates are globally significant results with moderate to good recoveries for a relatively coarse grind. Higher grade concentrates and better recoveries might be possible at finer grind sizes but this would need to be optimised through further drilling and test work. While the geometry and size of the Fe-V magnetite resources are yet to be fully evaluated, the remoteness of these prospects and lack of infrastructure in the Jervois area are limiting factors. The Au-Pt-Pd potential of selected mineralised intervals from the 2008 drill program at Casper, Coco and Misty were evaluated because orthomagmatic oxide-type deposits such as these are may host substantial Au-Pt-Pd mineralisation. The best assayed interval was from Casper with 47 metres at 0.57 ppm Au+Pt+Pd. This included 4 metres at 1.37 ppm Au+Pt+Pd. While this and other anomalous Au-Pt-Pd intervals were identified, the results are considered too low-grade and are typical of results from known orthomagmatic Fe-V deposits within Australia. Hence the Au-Pt-Pd economic potential of the magnetite-rich Unca prospects is low. However hydrothermal and/or vein deposits associated with these intrusions can not be discounted. Arafura focussed some of its early exploration efforts on assessing the uranium potential of the Lucy Creek prospect. A large radiometric anomaly was found to be coincident with strongly weathered and oxidised Fe-enriched units that coincide with the phosphatic Cambrian Red Heart Dolomite of the Georgina Basin and adjacent units. Historic exploration by CRAE demonstrated some potential for low-grade uranium mineralisation within this phosphatic unit and hence targeted shallow exploration drilling was conducted to evaluate the outcropping and near surface units. Most of Arafura's exploration activity occurred on the adjoining EL 24716. EL 24716 was transferred to Arafura's uranium spin-off company, NuPower Resources who concentrated their efforts on the adjoining EL 24716 exploring the P and U resources. Exploration drilling at the Lucy Creek prospect on EL 10215 found anomalous uranium mineralisation in this interval but the grades were localised and disappointing. The maximum assay was 133.5 ppm U and the average 23.5 ppm U. Both of the above exploration prospects were previously known to a limited extent based on regional mapping and historic exploration. The areal size of the Unca prospects has been greatly expanded from a few small outcropping prospects. Arafura was the first company to report drilling results from the Unca prospect and more targets remain to be tested.