Gold Mountain is set to chase a trail of porphyry copper and epithermal gold mineralisation in Papua New Guinea (PNG) after being granted the Green River project that features historic rock-chip samples running up to 8 per cent copper.
The 1047-square-kilometre project sits in the PNG lowlands – some 350km north-west of the company’s Wabag copper-gold project. It is in a region known to have a lower cost profile to explore and develop mines in the prospective, yet challenging PNG geography.
Management believes there has been only limited previous exploration of the porphyry-style mineralisation at Green River from the 1970s to 2000s and alluvial gold sampling in the past 40 years. But it has now acquired an extensive 522 stream sediment samples and some 25 rock-chip samples to help reboot exploration plans.
In 1997, an airborne magnetic survey was reprocessed over Green River and a revised geological interpretation produced a series of target areas for further exploration. Intrusive complexes were identified by the survey that were coincident with historically-mapped intrusive occurrences.
They were then followed up by a rock-chip sampling program that reported outcropping mineralisation in the areas of reported or interpreted intrusives. Gold Mountain says the rock-chip samples asserted the potential for large-scale porphyry mineralisation in the area, with surface chips returning copper grades as high as 8 per cent at interpreted intrusive targets.
The company says it is now in the process of budgeting ahead of kicking off field work, with the highest priority follow-up work expected to be focused on the area of high-grade rock-chip and stream sediment samples.
The Green River tenements lie on the intersection of an “arc-normal” structure – a control significant for major gold and copper-gold deposits throughout PNG. It is a country universally acknowledged for its wealth of copper-gold resources and features several 10 million-ounce-plus porphyry deposits.
Porphyry mines typically comprise bulk-scale operations with huge-tonnage, low-grade, easy-to-mine deposits that can stretch from surface to kilometres underground.
The company’s principal project in PNG is the Mongae Creek-Monoyal porphyry system in Wabag, which is the capital of the Enga Province in central PNG. The project has been subjected to several phases of exploration and is believed to also possess the potential to host significant copper-gold deposits.
The Wabag ground covers some 950sq km within the producing Papuan Fold Belt. The fold includes the world-famous Grasberg-Ertsberg mine just across the border in the Indonesian province of Papua and it is understood to be the biggest copper-gold mine in history.
Ertsberg means “ore mountain” in Dutch language. The mine featured two entire mountains of mineralisation that have been mined for 50 years into large open pits and deep, open block-caves beneath the earth’s surface.
With gold prices at all-time highs and significant copper resources being favoured by majors in significant mergers and acquisitions of late, why not look for the next major copper-gold discovery in an underexplored area of world-famous producing belt?
Is your ASX-listed company doing something interesting? Contact: matt.birney@wanews.com.au