Andean Silver Ltd could well be on the cusp of becoming a significant global silver player via its revitalisation of a historic precious metals project and its environs in southern Chile.
During the March quarter, the Perth-based junior increased its Cerro Bayo mineral resource estimate (MRE) to 9.8 million tonnes at 353 grams per tonne silver equivalent (AgEq) for 111 million ounces of AgEq (containing 47Moz of silver and 8Moz of gold).
This boost represents a total rise of 18 per cent (tonnes) and 22 per cent (oz) in the company’s inventory, which has grown by 439 per cent since it was acquired in 2024.
Located in the South American country’s Aysen region, production at Cerro Bayo originally started in 1995, yielding more than 100Moz AgEq up until June 2017.
The project sits in the western margin of the Deseado Massif, which is considered one of the premier epithermal gold-silver mining provinces globally, hosting world-class deposits like Newmont Mining Corporation’s Cerro Negro and boasting an endowment of over 4.9Moz of gold and 29.9Moz of silver for over 437Moz AgEq.
According to Andean, the updated MRE incorporates two new discoveries.
They are the Cristal and Pegaso 7 prospects at the Laguna Verde mine complex and, together, account for around 65 per cent of the inventory upgrade.
At Cristal, drilling revealed a central corridor that represents an intersection of multiple structural zones trending north-south and northwest-southeast.
The broad stockwork veining, which envelopes the principal veining occurring at the structural intersections, will be a focus of future open-pitable optimisation work.
Meanwhile, at Pegaso 7, several lithological and structural shoot controls were identified within the main north-south trending structure on top of multiple intersecting north-northwest-south-southeast trending subsidiary veins.
As it stands, significant quantities of vein and stockwork intercepts within 300 metres of the central corridor in cross-cutting and parallel zones are yet to be tested.
The junior has also started a large geophysical survey that supports the potential presence of an extended mineralised system extending north from the Droughtmaster and Sinter Hill prospects, with many of the planned drilling targets corresponding to known surface veins.
This geophysics has indicated the potential presence of a significant mineralised system, defining over a dozen structural targets extending north from Sinter Hill.
New north-south trending structures were also identified that demonstrated mineralisation potential over a two-kilometre strike length.
According to the company, these geophysical results linked the target zone at Sinter Hill to the known outcropping veins of Aguila and Meseta.
Sinter Hill gets its name from the fact it hosts a geological feature known as a sinter cap, a paleo-surface layer of silica-rich rock formed at the discharge point of a hot spring in an epithermal system. In effect, it acts as a cap over an underlying mineralised zone.
These structures, Andean said, were classic indicators of the presence of an epithermal system due to their direct association with the rising hot, mineral-laden fluids that create the sinter through precipitation as they cool at the surface.
Importantly, intact epithermal systems suggest a high potential for valuable mineral deposits, particularly gold and silver, as the entire process of hydrothermal fluid circulation and mineral precipitation remains undisturbed, thus preserving the full concentration of precious metals within the system and leading to higher-grade deposits.
In its March quarterly, the junior said it was effectively applying “boots on the ground” geology work, together with proven geophysical techniques, to aggressively explore over 330 square km of granted tenure in order to generate a robust project pipeline “which has already seen multiple major discoveries over the previous six months”.
During the coming year, the company plans to complete a geophysical campaign focusing on defining high-priority drill targets across the Pampa la Perra, Droughtmaster and Sinter Hill areas to generate a multi-year, district-scale ongoing program.
It will also drill brownfield targets in an attempt to grow the existing resources in the Laguna Verde and Cerro Bayo project areas.
In addition, Andean is looking at drilling greenfield targets, as well as beginning regional exploration campaigns (mapping, sampling and target generation) at Cerro Diablo and Los Domos.
So far three drill rigs have been deployed during 2025, with a fourth one now being considered as more results emerge from the geophysics program.
Andean chief executive Tim Laneyie said recent global events had reinforced the value of precious metal projects such as Cerro Bayo and “we look forward to demonstrating the value of the project as we establish a third avenue of value creation through the production restart studies”.
