Alma Metals Limited provided an update on drilling at the Briggs Copper Project in Queensland. Exploration is being funded by Alma under an Earn-In Joint Venture agreement where Alma can earn up to a 70% interest from owner Canterbury Resources Limited via a staged earn-in. The Project includes the Briggs Central copper deposit, where an Inferred Resource of 143Mt at 0.29% Cu has been defined (ALM release 18 August 2021).

The current program is testing Exploration Targets outlined at the adjoining Northern and Central Porphyry areas (ALM release 4 July 2022). Up to six deep diamond core holes, for 3,000m, are planned in the current program; four to test extensions of the Inferred Resource and evaluate the Exploration Target at Briggs Central, and two to evaluate the Exploration Target at the Northern Porphyry. The program is expected to continue into Second Quarter 2023.

The first hole in the program, 22BRD0013, intersected almost continuous copper mineralisation from surface (441.5m @ 0.21% copper from 8m down-hole depth to end-of-hole) with several higher-grade zones near intrusive contacts with older volcanic/sedimentary host-rocks. This hole ended in mineralisation grading 0.34% copper over the bottom 3.5m. The second hole, 22BRD0014, tested the northern end of the Northern porphyry target, and contained visible disseminated and quartz-vein hosted copper mineralisation over much of its length.

This hole was terminated at a down-hole depth of 536.5m after passing through a contact with a post-mineral mafic intrusion at 528.6m. Drilling has commenced on the next hole, 23BRD0015, to test the Briggs Central exploration target. Observations from 22BRD0014: 22BRD0014 intersected volcanic sediments, tuffs and fragmental rocks intruded by multiple phases of variably porphyritic felsic intrusions (granite to granodiorite composition) forming dykes and stocks.

The hole passed into a post-mineral intrusion at 528.6m down hole depth and was terminated at 536.5m. All rock types other than post-mineral intrusions contain variable densities of mm- to cm-scale porphyry-style quartz veins and are variably mineralised with copper and iron sulphides as disseminations in the rock mass, and/or in the quartz-veins. A broad interval (140m) of well mineralized porphyritic intrusive, and the associated volcanic sediment contact zone, is observed in the lower portion of 22BRD0014.

This intrusive has no surface expression and its discovery opens significant exploration opportunities targeting higher grade zones of copper mineralisation, particularly in the contact zone along the north-eastern margin of the Briggs system.