Nasty Knob

The Nasty Knob Prospect falls in CVC and the Owen Group lithologies, with the Great Lyell Fault separating the two units. CVC volcanics are composed of a series of competent rhyolite and andesite volcanics in the west and volcaniclastic units and siltstones in the east adjacent to the Great Lyell Fault and the Owen Group. There is structural complexity near the fault resulting in repeating lithologies. Several base metal anomalous gossan outcrops are found within the siltstone and volcaniclastic units adjacent to the fault, where sericitic and chloritic alteration pervades the units. Other mineral showings are exposed intermittently through Owen group talus shedding off of Mt Owen, along about 1km strike to the south

Target mineralisation at Nasty Knob is polymetallic exhalative VHMS mineralisation adjacent to the Great Lyell Fault. Broad zones of anomalous base metals within volcaniclastic and siltstone units associated with sericitic alteration have been intersected previously in drilling, and can be seen in outcrop also. Drilling at Nasty Knob has shown mineralisation to extend 500m below the gossans. Given the dominance of lead-zinc-silver mineralisation this suggests, at surface at least, being more distal from a Cu-Au locus.

Exploration at the Nasty Knob Prospect commenced in earnest in the 1980’s by BHP and RGC with several geophysical surveys, mapping, geochemical sampling and the drilling of two diamond drill holes; one in 1985 (HX1) targeting an IP anomaly intersecting 22m @ 0.27% Zn and one in 2004 (NCT003), an ambitious hole drilled by Newcrest targeting depth extensions to the gossans seen at Nasty Knob, which intersected broad zones of sub-economic mineralisation (24m@ 0.9% combined lead and zinc from 533m) some 500m vertically below the outcropping gossans. An electro-magnetic (EM) survey conducted by BHP in the 1990’s delineated a conductive anomaly along strike from the outcropping gossans at Nasty Knob. No follow up work was completed. The outcome of this exploration has shown that a large area of alteration and base metal anomalism exists within the Nasty Knob Prospect, anomalism that is seen to extend more than 500m from surface in a very prospective setting adjacent to the Great Lyell Fault.