Hillgrove Resources Ltd (Hillgrove) is exploring for base metals and associated gold mineralisation in the Cambro-Ordovician basement rocks of south-east South Australia. EL 6176 is one of 8 licences held by Hillgrove in this region. The licence...
Hillgrove Resources Ltd (Hillgrove) is exploring for base metals and associated gold mineralisation in the Cambro-Ordovician basement rocks of south-east South Australia. EL 6176 is one of 8 licences held by Hillgrove in this region. The licence is located in the Kanmantoo Trough and is interpreted to be a Cambro-Ordovician rift system and therefore prospective for exhalative/syngenetic base metals and for magmatic copper-gold mineralisation. The Wheal Ellen prospect is named after the historic Ag-Pb-Zn mine at the centre of the tenement which was worked in the mid 1800’s and early 1900’s. The area was previously held by Hillgrove under EL 3232, EL 4354 & EL 5627 (ENV 10811 CNO: 2036698 and CNO: 2039869). It is located approximately 44 km southeast of Adelaide and covers an area of 4.4 km square. During the first license year to 27th June 2019, exploration activities undertaken by Hillgrove included the relogging of 2 diamond core holes (WHDD003 & WHDD006) for structural and geological controls on mineralisation, orientation soil sampling and XRF analysis of different soil fractions and depths and saw the finalisation of university research on the indicator geochemistry of garnets from around the Wheal Ellen. Relogging was carried out by Dr Clement Fay of Model Earth and a detailed report is included, it concludes that the host rocks and alteration is very different to that seen at Kanmantoo, that sulphides occur parallel to bedding and are dominant in the mineralised zones, is smeared along the shear margins of the ore and infill fractured within quartz veins. It was also noted that there is an absence of a wide alteration halo. The university study was undertaken by Dr Paul Spry and Katherine Stott, who collected a range of drill core samples from the WHDD drill holes and undertook various studies that are summarised in a published paper in 2019 in Journal of Geochemical Exploration [See included report]. Their research focused on the geochemistry of alteration minerals and its use as a vector for discovering Zn-Pb deposits. The orientation soil survey saw 21 sites sampled from a single traverse across the mineralised zone at surface, at 10 cm, and 20 cm depths and screened into fine and coarse fractions for a total of 126 samples and 142 analyses with a Niton portable XRF instrument. Lead was a more reliable geochemical indicator than either Cu or Ag, with the fine fraction from 10 cm depth optimal. During licence Year 2, Hillgrove’s exploration activities included further soil and vegetation orientation surveying and XRF analysis, rock chip sampling for multi-element analysis of the hanging – and foot-wall sequences to establish the chemical footprint for undercover exploration, and the completion of a drone DTM survey by Dr Phillip Heath from the Geological Survey of South Australia. A total of 90 soil samples were collected from 10 sites along a single traverse at 25 m spacing across the Wheal Ellen lode. As part of the orientation survey, samples were split into coarse and fine fractions, and then split further into plastic and paper packaging. Samples from 3 sites were also compressed into course and fine “pellets”. Several ore grade rock samples located next to old shafts were also analysed (max values Zn 25.2%, Pb 14.2%, Ag282 ppm, As 0.4%), along with the bark of nearby trees (max values Cu 493 ppm, Zn 121 ppm). A total 56 rock samples from a long 2 travers were collected for multielement whole rock analysis. Results indicated that Pb had a wide geochemical dispersion within the host rocks and maybe useful in vectoring for this type of mineralisation. During licence Year 3, due to difficulties encountered in obtaining land access and on-going COVID restrictions, no on field activities were conducted during this reporting period. Off field activities conducted during this period include tenement management, statutory reporting, and on-going negotiations with landowners. During licence Year 4, no exploration activities were undertaken on the tenement due to changed landowner access regulations. During licence Year 5, final license year, no work was again carried out and the licence allowed to expire.
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