06:20 AM EDT, 04/16/2024 (MT Newswires) -- Fortuna Silver Mines ( FSM ) was at last look down 4.8% in US premarket trade after providing overnight Monday an update on its Yessi vein exploration program at the San Jose mine in Mexico.

Paul Weedon, Senior Vice President of Exploration, in a statement said, "Drilling on the Yessi vein, since the initial discovery hole in August 2023, has continued to establish a well-defined system, with recent results such as 1,327 g/t Ag Eq over an estimated true width of 3.0 meters from 604.85 meters in SJO-1444 and 1,036 g/t Ag Eq over an estimated true width of 8.1 meters including 2,910 g/t Ag Eq in SJO-1460 highlighting the potential for high-grade shoots. In addition, wide intervals such as the 179 g/t Ag Eq over an estimated true width of 17.5 meters in SJO-1455A highlight the potential for broad zones of mineralization".

According to the statement, drilling on the Yessi vein has continued with the dual objectives of testing for the limits of the Yessi vein and infilling the drill spacing to support initial resource estimations and mining studies. It said the Yessi vein has now been successfully drill tested over a 350-meter strike and a 450-meter vertical profile where it remains open up- and down-dip, as well as along strike to the southeast. The current phase of the program consisted of 10 additional holes for a total of 6,622 meters, it added.

Geological and structural logging of the drill core has confirmed the vein geometry as trending north-northwest, intersecting and merging with the north-south orientated Victoria Mineralized Zone towards the west, Fortuna said. It added: "Evidence is also emerging of higher-grade shoots within the structure demonstrating a moderate south-easterly plunge and often associated with high gold grades. Vein development is consistently associated with extensive alteration and brecciation with veining characterized by fine veinlets and fragments suggesting several phases of emplacement."

Additional drilling with three drill rigs will continue to test the depth, strike and infill of the current Yessi vein extent, the company said.