After pocketing $5 million in new money, Larvotto Resources is on the cusp of launching a 5250m exploration drilling program to infill and extend its Clarks Gully gold-antimony resource that sits just 4.7km north-west of its Hillgrove Mine in New South Wales.
The measured and indicated Clarks Gully resource – that is within 200m from surface – contains 266,000 tonnes at 3.8 per cent antimony and 2 grams per tonne gold, or 8.40g/t gold equivalent. And following the recent $5 million capital raise, management is also now eyeing a further $1 million injection via a share purchase plan.
The Clarks Gully deposit is hosted by a north-west-trending, steeply-dipping lode that intersects the major north-east/south-west-striking Hillgrove Fault. The trend also hosts the company’s Eleanora-Garibaldi and Brackins Spur deposits.
The Hillgrove Fault runs parallel to a second significant regional structure, the Chandler Fault, which lies about 8.5km to the south and 4.5km south of the Hillgrove Mine centre of operations.
The two major structures bracket nearly all of the significant gold-antimony-tungsten mineralisation in the Hillgrove region. They are largely ductile and mylonitic in character, cutting the granitoids and metasedimentary rocks.
This style of mineralisation is hosted by repeatedly deformed and altered metasedimentary rocks of the late Palaeozoic and Permo-Carboniferous granitoids of the New England Orogen.
More than 204 individual mineral occurrences have been identified in the area to date and are contained within an elongate area measuring some 9km by 6km. The mineralisation is typically developed as strike extensive – with occasionally more than 20km of known veining – and potentially depth-extensive, steeply-dipping lodes and reefs.
The economic mineral occurrences at Hillgrove show strong affinities to other orogenic gold-antimony deposits elsewhere, especially in New Zealand. However, it differs from the New Zealand deposits in that the ore-related mineral assemblage has been telescoped, with earlier deeper mineralisation overprinted at the same structural level by later, shallower mineralisation.
It means that at Hillgrove, structurally higher mineralisation typically has a higher antimony-to-gold ratio, with the latter being richer at depth.
Larvotto Resources managing director Ron Heeks said: “The Clarks Gully deposit extends from surface and remains open at depth. Significantly, the mineralisation is open in all directions and there is great potential for it to extend to depth as all of the other deposits in the field do.”
With the existing Clarks Gully resource lying above 200m vertical depth, some of the resource – and any extensions to it – may be amenable to open-pit mining. Only a small part of the near-surface deposit has been mined previously for antimony and gold, by a small open pit in the 1980s.
The company is encouraged by previous significant drill intercepts at Clarks Gully, including 7m at 2.33g/t gold and 9.16 per cent antimony (30.82g/t gold equivalent) and 15m at 1.61g/t gold and 5.18 per cent antimony (17.73g/t gold equivalent).
Larvotto is planning to plunge into the existing Clarks Gully resource with an initial 5250m of reverse-circulation (RC) drilling on a 20m-spaced infill pattern to increase its confidence in the existing resource numbers and also, if possible, extend it both laterally and vertically.
The company’s objective is to increase and update its current resource estimate and convert a significant part of its measured and indicated resources into reserves categories. Management says that once the Clarks Gully program is underway, it will also take on diamond drilling at the Bakers Creek reef system in a bid to define more of the almost legendary high-grade gold there.
It also aims to test the geochemical anomalism south of the Clarks Gully resource area to try and extend mineralisation in that direction.
Given the host style at Hillgrove, where mineralisation is typically contained in strike and depth-persistent structures, Larvotto is confident about being able to amplify its Clarks Gully resource.
If successful, the shallow mineralisation at Clarks Gully – if proven to be economically feasible – could see Larvotto kicking off a new era of mining at the 1.4 million-ounce gold equivalent Hillgrove operation, ultimately giving it a solid leg-up to bigger riches.
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By Doug Bright
