Since 2019, AbraSilver Resource Corp. has been paving the way for mineral exploration in Argentina. Chief Geologist, David O’Connor, outlines the company’s recent successes and best practices.
DRILLING FOR VICTORY
AbraSilver Resource Corp. (AbraSilver) is an Argentine-Canadian junior mineral exploration company, with two major ongoing enterprises in Argentina, namely the Diablillos silver-gold project and the La Coipita porphyry copper-molybdenum project.
“Salta Province, where our Diablillos site is located, was voted by the Fraser Institute as the best place in Latin America for investment in mineral exploration in 2021 and second best in 2022, having been beaten to first place by San Juan Province, where our La Coipita project is situated,” opens David O’Connor, Chief Geologist at AbraSilver.
“Billions of dollars are currently being invested in the development of lithium operations in Salta Province, three of which are within 30 kilometres (km) of our Diablillos project,” he continues.
This has led to infrastructure development in the area, including the planned construction of a new gas pipeline specifically to service the mining industry.
The current AbraSilver management team took the helm at the end of 2019 and have subsequently carried out three highly successful phases of exploration. The company employs up to 50 professionals and technicians on-site, including specialist consultants to advise on geology, hydrology, metallurgy, rock mechanics, engineering, and mine planning.
“The management team is very lean, which allows us to maintain a low cash burn rate,” O’Connor divulges.
The Diablillos project has undergone several phases of drilling by various companies over the past 30 years. A total of over 400 holes have been drilled so far, with the most advanced area being the Oculto deposit.
“When AbraSilver took over management control, the deposit had a resource estimated at 26.85 million tonnes (t), containing 80.3 million ounces (oz) of silver and 732,000 oz of gold. The most recent resource estimate at the Oculto deposit totals 51.31 million t, containing 109.37 million oz of silver and 1.30 million oz of gold,” O’Connor excites.
This recent preliminary resource estimation (PRE) was based on a milling throughput of 7,000 t per day, as well as hydrological studies that included geophysical profiling and water well drilling with pump testing. This incorporated 105,000 metres (m) of drilling in 457 holes.
The Diablillos project hosts several high-sulfidation epithermal silver-gold mineralised systems, including some new and emerging resources.
“The oxide silver-gold resource drillings were accompanied by detailed metallurgical studies that demonstrated high silver and gold recoveries as well as rock mechanics testing. These are used to inform engineering studies and drilling in preparation for infrastructure development,” specifies O’Connor.
Subsequently, due to the additional available resources that the findings revealed, water well exploration and hydrological studies are set to accommodate a potentially larger operation.
AbraSilver commenced resource drilling of oxide mineralisation at the Oculto deposit four years ago, alongside discovery and resource drilling of the adjacent JAC deposit, and reconnaissance drilling of peripheral target areas on which exploration is continuing, such as the Fantasma zone.
The Oculto zone is the most advanced resource studied so far, however, the more recently discovered JAC zone has so far achieved 346 grams per tonne (g/t) of silver and 0.15 g/t of gold from an 89m down-hole depth – a promising start.
The JAC zone, uncovered in August 2022, is a high-grade silver oxide dominant extension of the Oculto zone, measuring at approximately 800m in length and extending southwest of Oculto.
“The zone has several advantages over Oculto; being a higher-grade silver mineralisation, it possesses better metallurgical recoveries because it is very amenable to cyanide leaching and is more recoverable by gravity separation ahead of leaching,” O’Connor outlines.
The JAC zone comprises shallow oxide mineralisation, covered by approximately 50m of unconsolidated colluvium which does not require drilling and blasting, as with Oculto. The removing process prior to mining is set to cost about one third of the price per tonne.
“It would make economic sense to commence the operation with a pit at JAC, which would ensure a rapid payback of capital.”
“As well as these mineralised zones, the potential for additional resources exists in other areas peripheral to the Oculto zone. These are being explored using detailed structural mapping supported by magnetic surveys in preparation for targeted drilling,” he continues.
One such resource is the Fantasma zone, about 1km west of Oculto, where drilling is planned to expand the small historical silver resource and connect the two areas.
In addition to the oxide silver-gold resources at Oculto, JAC, and Fantasma, there is potential for a substantial sulphide copper-gold-silver resource beneath the oxide zone, which has been revealed by several deeper drill holes.
There is also potential for shallow porphyry-gold-molybdenum mineralisation in the Porphyry Camp, some 4.5km northeast of Oculto.
“These can both be considered targets for future exploration drilling,” O’Connor advises.
PUTTING PEOPLE FIRST
AbraSilver places great emphasis on safety, the environment, and local community relations. It co-operates with and aids local communities in a number of ways, including developing and providing service facilities, and assisting with health checks.
The company is always in regular communication with the Sub-Secretary for Mines regarding the advancement and development of its projects.
“The government is very supportive of our activities. We comply with environmental regulations and have very good relations with the local community,” enthuses O’Connor.
“We are also a leader in the employment of women and hold induction courses associated with Women in Mining (WIM),” he continues.
As such, last year the company was voted as the best organisation to work for by its members.
In addition, AbraSilver is very health and safety conscious. “We have a medical officer and an ambulance at the Diablillos camp. We always ensure the separation of vehicle and pedestrian areas wherever possible,” O’Connor tells us.
Furthermore, lightning conductors have recently been erected to address violent electrical storms in the wet season.
The Diablillos camp, which can accommodate 60 people, is kept clean, organised, and safe.
“Regular checks are made on the water quality of our wells. For example, drill tracks at Diablillos have been sampled to demonstrate that there is no contamination,” informs O’Connor.
An Environmental Impact Statement (EIS) is being prepared on Diablillos and will be submitted before the end of 2023.
Furthermore, a new core shed has been built on-site at Diablillos to house the important drill core, which was previously left out in the open. The shed protects over 60,000m of core, which is stored on racks and accessed by a mechanical lift. Subsequently, each hole is catalogued and cross referenced by area and drill date.
The core is routinely logged and photographed, then sawn in half, with half the core sent to SGS laboratory for analyses whilst the remaining half is stored to ensure the continued safety and functionality of the drill core.
“The government is very supportive of our activities. We comply with environmental regulations and have very good relations with the local community.”David O’Connor, Chief Geologist, AbraSilver Resource Corp.
In November this year, AbraSilver will announce a maiden oxide resource at the JAC zone, together with updated oxide resource estimates at the Oculto and Fantasma zones.
These resources, alongside associated metallurgy, engineering, and financial studies, will be incorporated in a preliminary feasibility study (PFS), to be completed by January 2024.
In addition to the PFS on the Oculto, JAC, and Fantasma zones, studies for potential resources will also be carried out on the exploration of the peripheral areas.
“This will include detailed structural mapping and analyses, supported by magnetic surveys, which are already underway,” O’Connor informs us.
“As well as the Oculto-JAC epithermal area, in which systematic resource drilling has generated oxide resources, there is a considerable copper sulphide system beneath the oxide zone which has substantial associated gold and silver content. This is a target for future resource drilling,” he adds.
Meanwhile, exploration drilling for copper-gold-molybdenum porphyry mineralisation in the Porphyry Camp at Diablillos is scheduled for a later date.
It is anticipated that continued exploration for copper porphyry mineralisation at the La Coipita project in San Juan Province will proceed via a joint venture with a major mining company to help secure financing for future exploration campaigns.
“There are several mining companies that are watching the development of the Diablillos project with interest, some of which have visited the site. We anticipate that the PFS will be followed by a definitive feasibility study (DFS),” O’Connor clarifies.
At the DFS stage, AbraSilver will evaluate all options for advancing the project forward, with the aim of delivering the best outcome for its shareholders.
“As a result, the project will move rapidly to a construction decision” O’Connor concludes.