Galena Mining Ltd (ASX:G1A) (FRA:GM6) has achieved key objectives from the 2020 Abra Drilling Program with a subsequent updated JORC 2012 resource estimate helping to increase confidence in the Abra Base Metals Project in Western Australia.
The April 2021 resource has been independently prepared by Optiro Pty Ltd based on assays from the completion of the 2020 drilling program, which consisted of 57 holes for a total of 24,834 cumulative metres of diamond core drilling.
The resource estimate now totals 34.5 million tonnes at 7.2% lead and 16% silver, comprising 16.9 million tonnes at 7.4% lead and 17% silver in the indicated resource category and 17.5 million tonnes at 7% lead and 15% silver in the inferred category.
To feed into optimised mine plan
Galena managing director Alex Molyneux said the project now had in excess of 100 kilometres of drilling in its database and the geological confidence and understanding of the deposit continued to improve.
He said: “Almost all of the new holes were drilled within the previous mineral resource envelope and over 75% of those holes achieved expected or better results.
“This mineral resource update will now feed into an optimised mine plan and mine development will allow for underground drilling to continue resource development, particularly the conversion of significant inferred mineral resources associated with the Core Zone mineralisation, which remains open in several directions and also hosts the interpreted copper-gold zone.”
Drilling objectives achieved
The completed 2020 Abra Drilling program was designed to achieve three specific objectives - mainly focused on the original resource estimate and potential grade and continuity risk of certain areas within that estimate:
- Lead-silver orebody infill drilling – Some infill drilling that had previously been planned to take place from underground once the decline was in place was pulled forward into the 2020 Abra Drilling Program. This aimed to further tighten the drill-hole spacing over the first four years of proposed production to 20 by 20 metres and up to 30 by 30 metres or better, compared with a more variable drilling density of up to 40 by 40 metres and up to 60 by 60 metres in that area previously;
- Drilling into selected lead-silver ‘metal rich’ zones – Some drill-holes successfully targeted selected areas within the Abra lead-silver mineralisation where higher concentrations of metal (in both grade and thickness) were projected from previous drilling campaigns, in particular drill-hole AB147, which became the best high-grade lead-silver drill-hole ever at Abra, and the follow-up drill-holes that were added to the program in its vicinity; and
- Gold-copper exploration – Some of the drilling, in particular drill-hole AB195, successfully targeted the newly interpreted gold and copper drilling targets to the south and south-east of the lead-silver mineralisation and at depth.
The first two of these objectives enable the company to optimise mine planning, which is now underway.
Stylised geological cross section of Abra at 660,575mE looking east
Resource update advantages
The April 2021 resource has some major advantages over its predecessor including:
- Increased predictability – Optiro was able to confirm a substantial increase in the predictability of the April 2021rResource model vs the October 2019 resource;
- Indicated material is more consolidated around the shallower, northern area of the deposit – The Apron Zone is now largely indicated in the area that was previously inferred between the two northern limbs of Indicated in the October 2019 resource; and
- Increased confidence within indicated material – The drilling density within the indicated resource outline is much higher for the April 2021 resource than for the October 2019 resource.
Next steps
Various project enabling/early construction works have been in progress at Abra for some time, with the project 15% complete as of March 31, 2021.
Certain key works have been completed, including a 280-unit mine site village, mining of the box-cut, installation of production water infrastructure (bores, pumps and water reticulation), installation of site communications, and various site clearing, roadworks and civil works.
Conclusion of the 2020 drilling program, along with the updated resource estimate is a key milestone to further progress Abra to a final investment decision (FID).
The outcome of the work shows that Abra continues to demonstrate its standing as a long-life, globally significant high-grade lead-silver project.