Blackstone Minerals (ASX: BSX) has received promising historical assay results from the deepest hole drilled at its new Mankayan project in the Philippines.

Best known for its nickel aspirations in Vietnam, Blackstone recently moved to acquire 100% of Mankayan via an all-scrip merger with owner-operator IDM International.

Sitting in the mining-focused province of Benguet on the main Philippine island of Luzon, Mankayan is strategically located 2.5 kilometres along strike of the Lepanto gold mine and Far Southeast project.

Unreleased results

Significant intercepts for the drill hole were 432 metres at 1.25% copper equivalent from 692m and 210m at 1.60% copper equivalent.

Drilled in 2013 by Gold Fields, these results had not previously been released, according to Blackstone managing director Scott Williamson.

“Drillhole BRC-60 is one of the best intersections into the Mankayan copper-gold porphyry, confirming the project as one of the best undeveloped copper-gold projects globally,” Mr Williamson said.

“Mankayan remains open at depth and along strike to the north and we are fully committed to allocating resources to thoroughly explore the full extent of the mineralisation.”

Angled orientation

One of only a few angled drill holes in the Mankayan project, BRC-60’s purpose was to explore for deeper high-grade copper-gold mineralisation, with drilling done at an angle of 70 degrees to increase the likelihood of intersecting vertically oriented mineralisation and intense quartz veining.

Gold Fields sampled and assayed the hole from 650m to the end of hole at 1,491m, while IDM recently sampled and assayed the hole from 432m to 650m.

The results confirmed that the porphyry system extends significantly deeper than previously understood.

Extensive experience

Mr Williamson said that Blackstone’s extensive experience in base metals mine development, particularly in South-East Asia, would support the success of the Mankayan project. 

“Blackstone’s proven track record with the Ta Khoa nickel project provides valuable insights and synergies that can be directly applied to the Mankayan project,” he said.

“Through cost-effective exploration techniques, advanced development strategies and the ability to deploy equipment from Ta Khoa (such as geophysics, drilling and metallurgical testing), Blackstone brings invaluable operational efficiency to Mankayan.”