The Scott Hill (EL 3587) licence area, centred about 80 km north-west of Manna Hill, is the westernmost of 5 adjacent tenements held by PepinNini Minerals within the eastern Adelaide Geosyncline close to where it abuts the Curnamona Province. This...
The Scott Hill (EL 3587) licence area, centred about 80 km north-west of Manna Hill, is the westernmost of 5 adjacent tenements held by PepinNini Minerals within the eastern Adelaide Geosyncline close to where it abuts the Curnamona Province. This boundary region has long been thought to have a highly favourable geological and structural setting for metallogenesis, and was recognised by grant licensee PepinNini Minerals (PepinNini) as being prospective for stratiform Pb-Zn-Ag, stratiform Zn-Pb, strata bound Cu-Au, iron oxide copper gold (IOCG) and Tertiary roll-front uranium styles of mineralisation. During licence Year 1, no field work was undertaken. PepinNini assessed available previous exploration data, and then designed an exploration drilling programme to investigate a Pb-Zn-Ag-Au target at Eukaby Hill. The programme involved 4 inclined RC holes for a total of ~500 m of drilling, to test magnetic anomalies located south of and aligned parallel to a major ENE trending, deeply crust-penetrating fault zone which was envisaged, along with conjugate fault zones to the east, to control the emplacement of mineralisation in the area. The work proposal was submitted to PIRSA during September 2006 as part of a submission for the grant of PACE Initiative Theme 2, Year 4 collaborative drilling project subsidy funds. No work occurred on the licence during Years 2 and 3, except for the in-house remodelling of historical geophysical data, because of the JV's commitment of technical resources towards progressing the nearby Crocker Well uranium project. During licence Year 4, exploration operator Sinosteel PepinNini Curnamona Management (SPCM) acquired a detailed ground gravity survey during March-April 2010, when 1199 new stations were read on six regular grids at various station spacings of 1 km x 500 m or less. The new gravity data identified a number of discrete positive gravity anomalies, as well as enabling the identification of regional structures and the mapping of possible palaeochannels. During licence Year 5, SPCM drilled four selected gravity anomalies with 4 inclined RC and 3 inclined NQ diamond holes, for a total penetration of 267.6 m of precollars and 1718.35 m of coring. All of the drillholes ended within clastic sediments of the Adelaidean Wilyerpa Formation, and no hole penetrated into the inferred underlying older Palaeoproterozoic Willyaman Supergroup basement. Common to abundant sulphides, dominated by pyrrhotite-pyrite, occurr as disseminations and distinct bands throughout most of the Wilyerpa Formation interval that was drilled. The bulk amount of these sulphides in some of the lithologic units intersected may be sufficient to explain the defined gravity features. Drillhole DD11SH001, targeting discrete positive gravity feature Anomaly E3, intersected a thick sequence of very dark to black weakly graphitic shales with common to abundant disseminated and banded pyrrhottite. Assaying of the drill core for Mount Isa style mineralisation did not return anomalous geochemistry. However, drillhole DD11SH004 intersected numerous folded, multiphase mineralised veins within the modelled gravity feature Anomaly S1, which were considered highly encouraging and possibly indicative of an igneous intrusion - related mineralised system at depth. The layered quartz-carbonate veins are dominated by Zn-Pb+Cu-As-Ag-Py mineralisation. Drillhole DD11SH003 did not intersect significant mineralisation, but an interpretation of Geoscience Australia's regional AEM data indicated that a strong conductive feature exists at depth that may coincide with the gravity feature Anomaly C1. However, the now prioritised gravity Anomaly S1 was not covered by the AEM survey. During licence Year 6, a detailed infill ground gravity survey was completed over the Eukaby mines prospect during April 2012, when 230 new stations were read on variably spaced regular grids. The resulting data delineated two discrete positive gravity anomalies which had been identified earlier (W1 and W2), besides further contributing to the identification of regional structures and the mapping of possible palaeochannels. Geophysical modelling of the merged gravity data was performed by two consultants, who between them generated over twenty possible anomaly source bodies at <300 m inferred depth which may reflect buried rocks containing 10-15% sulphide content. The aforementioned two main discrete positive gravity anomalies were originally interpreted by the JV partners to represent possible igneous intrusion/porphyry - related or IOCG-(U) style mineralisation at depth. Surface mineralisation, such as that noted as occurring at the Eukaby mines, was interpreted to represent the products of upward leakage of mineralised fluids into the cover sequence, which would have come from a stalled intrusive body within the underlying basement. However, it now appeared to SPCM that the mineralisation found in these areas may be related to undefined younger, Delamerian igneous intrusive activity, and consequently it is more likely to represent epithermal style mineralisation. Accordingly, due to age constraints imposed by this scenario, it was deemed unlikely that IOCG style mineralisation is associated with the observed surface mineralisation. Notwithstanding the changed exploration model, it was clear that the gravity and geochemical anomalies present in the vicinity of the Eukaby mines would require further evaluation and drill testing. During licence Year 7, no work was done. A change in ownership of the subject EL 4784 occurred on 22/9/2014, when farminee Sinosteel Uranium purchased grant licensee PepinNini's 40% share of the joint venture and became the sole tenement holder. During licence Year 8, Sinosteel Uranium inspected some historic abandoned small-scale mines located on EL 4784, and 9 grab rock samples were collected from mine spoil heaps for assaying. During the company's field reconnaissance, several historical drillholes were also located and had their true positional information captured by GPS, together with GPS coordinates for a large number of old workings that were not shown on existing published maps. During licence Years 9 and 10, no work was done. Instead, exploration activity was directed elsewhere within the company's adjacent project tenements. At the end of the previous reporting period, a partial surrender from 422 km2 to 379 km2 was made on renewal. During licence Year 11, on renewed exploration licence EL 6026 no field work was undertaken, with exploration activities again focused on adjacent tenements. During licence Year 12, no field work was undertaken, with exploration activities again focused on adjacent tenements.
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