Andean Silver (ASX:ASL) says it has picked up rock chips grading as high as 135,800 grams per tonne silver equivalent at its Cerro Bayo Project in Chile.
CEO Tim Laneyrie says these are the highest grades ever encountered at the project in its entire 40-year history.
“To find those results in veins next to mines depleted 20 years ago again highlights the potential for the entire district,” he says.
Shares ended Friday (24 January) up nearly 5% to trade back above $1 following the news, giving the explorer a market capitalisation of $153.2 million.
The 135,900g/t sample was taken from the historic Cascada underground mine, which is not currently included in the existing resource.
Other rock chip results, which have extended the Droughtmaster corridor that also sits outside the existing resource to over 3km of strike, included silver equivalent grades ranging from 4,613g/t to 14,514g/t.
Laneyrie tells Mining.com.au the actual main grades historically at Cerro Bayo are not much different from those rock chips samples.
“In fact, they’re very wide veins just below the surface. The ultimate aim is to hit one of these very high-grade feeder systems and you’ll see these grades continue,” he explains.
“We’ve got these grades in the underground mines, proximal to the mill currently. We’re seeing, up to probably 800, 900, 1,000 grams per tonne, silver equivalent over drill metres.”
The 285km2 Cerro Bayo Project was in production for over 15 years, producing more than 45 million ounces of silver and 650,000 ounces of gold. The operation has been on care and maintenance since October 2022.
The project hosts a high-grade resource of 8.2 million tonnes @ 342g/t silver equivalent for 91 million contained ounces. The resource comprises both open pit and underground mines across two mining complexes within the Cerro Bayo Project.
Laneyrie says the rock chip results confirm the belief that they are big vein systems that continue for a long way.
“The area itself hasn’t been fully picked over, and there’s a lot more new discoveries to be made within the district itself, even after 40 years of exploration history, which is outstanding for this type of area,” he says.
Andean has been ramping up its field work along the Droughtmaster Corridor which continues to define strike extensions along the key Claudia veins that define the western graben margin of the corridor.
Mapping and sampling of the Claudia vein initially defined a 1.6km zone of mineralisation within the northern extent of the corridor.
Additional mapping and sampling work to the south has confirmed a further 1.5km of strike to the Claudia vein making it one of the largest, near continuous veins in the district.
Andean says it is almost double the strike of the Coyita Vein at Laguna Verde.
Detailed mapping and sampling has also extended the recently discovered east-west trending veins by up to 300m of strike to a total of 500m.
“The pipeline of drilling targets that continue to be generated at Droughtmaster will set Andean up for a multi-year exploration campaign,” Laneyrie says.
“At the same time, our extensional drilling continues to deliver outstanding results at Pegaso 7 and Cristal, and with our third drill rig drilling at Coyita, will continue our aggressive resource extensional drilling campaign across multiple existing resource areas.”
A resource update is slated for completion in the first quarter of the year. This will be followed by a geophysics campaign that is due for completion in the second quarter.
Andean Silver, formerly Mitre Mining, is an Australian mineral exploration and development company focused on advancing its 100% owned flagship Cerro Bayo Silver-Gold project in the Aysen region of Southern Chile.
Write to Angela East at Mining.com.au
Images: Andean Silver
