Alma’s final assays from core drilling at its Briggs copper project in Central Queensland have proven beyond a doubt that a substantial upgrade to current resource is on the cards in the third quarter.

The final assays have once again extended the extent of copper-molybdenum mineralisation beyond the existing Briggs Central Inferred Resource of 143Mt at 0.29% copper with hole 23BRD0016 returning a thick 365.7m intersection grading 0.24% copper and 28 parts per million (ppm) molybdenum from a down-hole depth of just 6.3m.

23BRD0016 extends the known limits of mineralisation by over 150m to the northeast of the resource while confirming the presence of near-surface, higher grade mineralisation.

Alma Metals (ASX:ALM) notes that multiple intersections with greater than 0.2% copper have now been recorded over a strike of more than 1,650m within the 2,000m long geochemical anomaly, which is outside the current Inferred Resources’ strike length of 450m.

This drilling was aimed at testing the current Exploration Target of 455Mt to 850Mt grading between 0.2% and 0.35% copper across Briggs Central, the Northern Porphyry and the South Porphyry.

While Exploration Targets are no replacement for proper Resource estimates, they do provide a hint of the growth potential at the Briggs project.


Briggs and future plans

Alma is earning a 70% stake in the Briggs project from Canterbury Resources (ASX:CBY) by spending up to $15.25m on exploration over nine years.

Its interest in the project is fuelled by the easy-mining, shallow porphyry deposit.

Porphyry mines are huge, responsible for about 60% of the world’s copper, most of the planet’s molybdenum, and significant amounts of gold and silver as well.

While they typically have low grades between 0.2% to 0.7% copper equivalent, this is more than made up for by their large volumes.

The project is also close to key infrastructure, including sealed roads, rail, grid power, gas pipelines and the deep-water port at Gladstone, which is just 50km to the east.

Resources are currently limited to the Central Porphyry at Briggs, a porphyritic granodiorite stock where mineralisation occurs in stockworks of quartz veins containing quartz, chalcopyrite, minor molybdenite, potassium feldspars and locally anhydrite.

Meanwhile, the Northern and Southern Porphyry’s occur along strike from the Central Porphyry and show evidence of porphyry vein stockworks and banded silica bodies at surface similar to those seen at the Central Porphyry.

Drilling will resume early in the third quarter to test further extensions of the deposit as well as assess multiple higher grade zones in detail.



This article was developed in collaboration with Alma Metals, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.