Drilling by Alkane Resources (ASX: ALK) at the Boda and Kaiser prospects within its Northern Molong porphyry project in New South Wales has resulted in the discovery of “significant porphyry gold-copper mineralisation” increasing in thickness and grade at depth.
Boda was tested with one diamond drill hole 200m beneath a previously-defined zone of gold mineralisation located at the northern end of the Boda Intrusive Complex.
The hole intersected a thick zone of gold-rich pyritic stringers from the top of hole vectoring downhole to a gold-rich chalcopyrite-dominant core, with chalcopyrite forming as disseminated blebs and in quartz veins.
Two monzonite porphyries were intersected in the first 200m downhole intruding into more primitive volcaniclastics and lavas that host the majority of the potassic alteration.
Intercept highlights were 502m at 0.48 grams per tonne gold and 0.20% copper from 211m; 313m at 0.62g/t gold and 0.17% copper from 228m; and 12m at 3.28g/t gold and 0.67% copper from 419m.
Drilling near Kaiser comprised five reverse circulation holes and one diamond drill hole for a total of 1557m, with mineralisation characterised by thin zones of fine disseminated chalcopyrite and bornite associated with minor silicification.
Assays confirmed strong gold-copper porphyry mineralisation 200m southeast of the small near-surface, porphyry-style, gold-copper Kaiser deposit.
Best intercepts were 40m at 1.30g/t gold and 0.22% copper from 0m including 10m at 2.86g/t gold and 0.36% copper from 0m.
Two drill holes for a total of 438m were also drilled at the nearby Glen Hollow prospect to test geochemical anomalies outboard from the Comobella Intrusive Complex (CIC), approximately 7km to the northwest of Kaiser.
Drilling demonstrated the continuation of significant porphyry mineralisation dipping to the northeast, including 42m at 0.27g/t gold and 0.19% copper from 63m.
Boda and Kaiser are part of the greater Northern Molong porphyry project which incorporates three exploration licences – Bodangora, Kaiser and Finns Crossing – over 110sq km of the northern Molong Volcanic Belt in NSW’s central west region.
The belt is considered highly-prospective for large porphyry gold-copper mineralisation, as demonstrated by the world-class Cadia Valley porphyry district located to the south.
Alkane managing director Nic Earner said the results suggest an “exciting discovery” in a region with a history of delivering large, low-grade and long-life gold-copper mines.
“The project area has already delivered some strong indications of a big porphyry system near surface at Kaiser and along with the results from Boda, we can see clear evidence of Cadia-style mineralisation and grade over hundreds of metres,” he said.
“We will be prioritising follow-up drilling in an effort to determine the scale of this highly-encouraging discovery,” Mr Earner added.
Mr Earner said Alkane had established a geological framework for the region which highlights strong similarities with Cadia, albeit structurally more complex.
It has shown that a stratigraphic sequence very similar to that at Cadia exists within Alkane’s project area and that mineralisation is hosted by very similar rock types at similar stratigraphic positions.
The Kaiser-Boda target zone has been mapped over a north-south strike length defined by monzonite intrusives, extensive alteration and widespread low-grade gold-copper mineralisation.
At midday, shares in Alkane Resources were trading 18.18% higher at $0.455.