Exploration

Surrounding the Kanmantoo Operation and extending for over 4,000 sq kms in the south-east of South Australia, Hillgrove is exploring for Cu porphyry and sediment hosted Cu-Au deposits.

Hillgrove hold 100% of a series of Exploration Licenses covering 4,187 sq kms in south-east South Australia in the Cambrian-Ordovician Kanmantoo Province. Over 95% Of the Kanmantoo Province is covered by the Tertiary Murray Basin which has limited past exploration.

Recent work by Hillgrove and the GSSA has highlighted the opportunity for large scale Cu-Au deposits including;

1. back-Arc Porphyry Cu-Mo-Au mineralisation, (e.g. Dexing, SE China (view here); and
2. intrusive related sediment hosted Cu-Au-Ag mineralisation (e.g. Winu in Western Australia).

The licenses comprise three geographic groups:

• Near Mine which typically lie within a 5km radius of the Kanmantoo Copper Mine. The Stella and North-West Kanmantoo projects are priority targets within the near, mine area.
• Milendella Fault Project located ~50kms northeast of the Kanmantoo Mine and prospective for Back-arc porphyry Cu deposits.
• Dukes Project located 50 – 200 kms south-east of Kanmantoo and prospective for intrusive related sediment hosted Cu-Au deposits.

“Winu” style sediment hosted Cu-Au-Ag-Bi – Dukes Project

• 5,650 sq kms of granted tenure along 170 kms of the crustal scale Dundas Fault zone and basement high.
• Multiple zones of coincident magnetics, gravity, geochemistry, alteration, and mineralisation.
• Petrology confirms “Winu” style alteration and vein paragenesis.

“Winu” style sediment hosted alteration and sulphides have been identified at several sedimentary basins in the Dukes Project area in legacy drill holes and require further investigation including,

• Sherlock sub-basin with 11% Cu
• Elevated Cu-Pb-Zn to 1060ppm Cu in GSSA drilling in sediments in Sherlock Basin (MOO25)
• Sediments in Wynarka sub-basin to amphibolite metamorphism overprinted by K-spar, chlorite, epidote veining with elevated Cu, Bi, Ag, Mo, Pb, Zn (COP56)
• Sediments in Keith sub-basin with garnet, epigenetic pyrrhotite, chalcopyrite (CODD3)

Note: All the exploration company legacy drill holes were focused on testing airmagnetic anomalies and therefore are biased against discovering sediment hosted mineralisation.

Back-Arc Porphyry Cu-Mo/Au – Milendella Project

• 115 sq kms of granted tenure along 14 kms of a crustal scale fault zone (Coorong Shear Zone) with attendant Intrusive Related Cu-Au mineralisation.
• Coincident IP, magnetics, geochemistry and skarn style alteration and mineralisation.

Multiple small Cu-Au workings in contact metamorphic aureole of magnetite-amphibole diorites.

In addition, HGO’s geochemical sampling of its own and legacy drill holes and outcrops shows a number of areas in the Kanmantoo Province with attractive Cu fertility indexes, in particular along the Coorong Shear Zone corridor. GSSA’s recent work at Anabama supports these fertility indexes along this zone (note the red labels in the fertility plot). Further south in Hillgrove’s tenement area is a small outcrop of Cu-Mo porphyry.