Junior explorer Antipa Minerals (ASX: AZY) has confirmed that joint venture partner Rio Tinto Exploration (ASX: RIO) will proceed with the next stage of its phased earn-in to the Citadel copper-gold project, in Western Australia’s prolific Paterson Province.
Rio recently earned a 51% interest in Citadel after sole-funding $11 million of exploration expenditure on the 1,330 square kilometre tenement package.
Exploration commenced in October 2015, following the signing of the farm-in agreement with Antipa.
The expenditure milestone triggered the formation of the Citadel joint venture between the two parties.
Under the terms of the farm-in, Rio has notified Antipa that it will spend an additional $14 million over five years (updating the terms that was initially slated for three years) to increase its interest in Citadel to 65%.
Rio has indicated it will kick-off a $2 million field exploration program in April, with activities continuing through the remainder of the year.
The program will feature induced polarisation surveys along favourable structural corridors; interpretation of a recently-completed airborne gravity survey over the entire acreage; and evaluation of the Calibre gold-copper-silver deposit within Citadel, including possible drilling.
It will also include a remodelling of the project’s broader Magnum Dome deposit and additional drilling targeting high-grade gold-copper mineralisation.
Antipa executive chairman Stephen Power welcomed Rio’s decision to proceed to the next stage.
“We are very pleased and we look forward to extending what has been a very rewarding partnership [with Rio] to date,” he said.
“The Calibre and Magnum resources within Citadel have significant potential for further growth which, together with our regional exploration targets, establishes excellent growth prospects for Antipa.”
The project hosts a global mineral resource of 63.8 million tonnes at 0.8 grams per tonne gold and 0.2% copper for 1.6 million ounces gold and 127,000t copper.
The resource is split over two deposits – Calibre with 47.7Mt at 0.9g/t gold and 0.15% copper for 1.3Moz gold and 69,500t copper; and Magnum with 16.1Mt at 0.7g/t gold and 0.37% copper for 339,000oz gold and 57,800t copper.
Both deposits are within 45km of Winu which Rio has formally moved from an “advanced project” to study stage.
Subject to Rio earning a 65% interest in Citadel and Antipa then electing not to contribute to expenditure to maintain its 35% interest, Rio has the ability to increase its interest to 75% by sole funding a further $35 million within three years.
At morning trade, shares in Antipa were steady at $0.014, while Rio was up 0.82% to $100.30.