An area located within the APY Lands of north-western South Australia, near the SA/WA State Border and covering land south of the Tomkinson Range which is largely covered by in situ and transported alluvium and aeolian sands, was taken up to...
An area located within the APY Lands of north-western South Australia, near the SA/WA State Border and covering land south of the Tomkinson Range which is largely covered by in situ and transported alluvium and aeolian sands, was taken up to explore for possible economic ultramafic igneous rock - hosted nickel-copper sulphide mineralisation, platinum group metals (PGE) and vanadium-rich chromite-ilmenite-magnetite deposits. During the first licence year, Mithril attempted to obtain heritage clearances to allow for access onto the most prospective parts of EL 4047. This work was unable to be completed; however, access was granted to the western 20% of the licence area. The central 60% of the licence area had access denied; and an area in the eastern part of the licence could not be cleared by the APY because there was difficulty in locating Traditional Owners for it. As a consequence of Mithril's open file research (including of data from past PIRSA drilling) and study of satellite imagery, it was concluded that the western cleared area is overlain by deep Tertiary to Recent sheetwash cover sediments, and therefore would be less prospective than had been first thought. The most prospective (for inferred buried Ni, Cu, Pt/Pd and V mineralisation) parts of the licence were believed to lie within the central access denied area, where Giles Complex rocks outcrop and lie at shallow depth. No work occurred during licence Year 2, pending the completion of heritage clearance surveys over the remaining potentially prospective ground still awaiting access permission. During licence Year 3, the area west of the Watarru - Pipalyatjara Road which had been cleared for low impact exploration access was explored by Musgrave Minerals via regional geochemical soil and rock chip sampling (14 +18 samples respectively collected and assayed). The field work programme was designed to examine outcropping lithologies for evidence of mafic-ultramafic intrusive magmatic targets, and to assess their potential to host nickel sulphide mineralisation. In addition, a general reconnaissance was conducted to determine which geochemical and geophysical exploration methods would be most suitable for use in this area. Preliminary rock chip and soils sampling of the very rare outcrops failed to disclose any anomalous geochemistry. The outcrops represent less than 1% of the area, so this result was not surprising. The remainder of the area did not appear to be amenable to surface geochemical sampling. Geological mapping identified a hitherto unrecorded exposed occurrence of Giles Complex layered gabbro and pyroxenite. This particular small outcrop appeared to be magnetically transparent, leading to the proposition that significant amounts of similar intrusion-related prospective mafic/ultramafic lithology may lie concealed below cover in the EL 4047 area. It was recommended that scout regional vacuum or aircore drilling to the colluvium/saprolite interface should be done to provide a more detailed geological framework for the area, in addition to providing regional geochemical information. In 2010, permission was requested and was given to fly an airborne VTEM survey across the south-eastern portion of the tenement. During licence Years 4 through 7, the activities undertaken on EL 4047/5205 were jointly reported with those for other Musgrave Project tenements, and so are not included in the subject dataset. The recently approved full surrender of the subject EL 5205 has triggered the following release of additional information, as described in the licence final report: - In 2011, Musgrave Minerals completed no field work on the tenement, only planning for a VTEM survey and completing data reviews. - In 2012, Musgrave Minerals completed two heritage clearance surveys, but only minor on-ground field work due to ongoing Aboriginal heritage protection issues. 17 rock chip samples were collected and two days of geological mapping were completed. A 697 line km VTEM survey was flown which delineated a number of targets. A coincident VTEM/structural/nickel geochemical (0.11% Ni) anomalous target was defined from this work. In 2013, Musgrave Minerals conducted three Aboriginal heritage clearance surveys, geological mapping, coarse lag sampling, stream sediment sampling, rock chip sampling and a small fixed loop ground EM survey to follow up two selected adjacent airborne VTEM anomalies (called Ehrohir and Ellandan). One gossanous sample was identified during geological mapping at another VTEM anomaly (Smeagol prospect), that returned 0.23% Ni, 0.17% Cu and 220 ppb combined Pt and Pd. One test line of EM readings was run over this gossan during November 2013. In 2014, Musgrave Minerals was unable to complete heritage clearances over prospective areas due to the lack of availability of anthropologists and budgetary constraints. Some geological mapping, coarse lag sampling, rock chip sampling and a small ground EM survey, of 9 traverses totalling 7.15 line km, were completed. The geological mapping focussed on finding further occurrences of gossan similar to that seen at the Sméagol prospect, and one further narrow horizon of the same lithology was located. Detailed moving loop ground EM profiling (50 m station spacing) was completed across and around the Sméagol gossan in late April 2014, however, a bedrock conductor was not identified. Ground EM profiling was also completed then at the Elladan target at 100 m station spacing, which did serve to constrain the location and geometry of a conductor which was interpreted to have a moderate strike length (~185 m), with a steep SW dip and moderate SE plunge, but appeared to be depth limited (16–18 m). The conductance of the target (550–650 S) indicated that if it is caused by sulphide mineralisation, it is probably a stringer zone or very thin mineralised horizon. A decision to relinquish EL 5205 Bryson Hill was made in early December 2015 following a strategic review and in response to corporate budgetary constraints. Musgrave Minerals had spent $472,821.47 on exploring the licence since 25/2/2013, whilst overall, Mithril Resources and Musgrave Minerals had spent a total of $896,829.15 on it over the whole eight year period of tenure.
More +