TORONTO (miningweekly.com)  –  An exploration programme at the San Dimas precious metals mine, in Durango state, Mexico, had extended the mine’s top-producing vein beyond a minor vault that was previously regarded as its limit, TSX- and NYSE-listed Primero Mining reported this week.

The 2014 exploration programme was delivering a host of positive results at the top-producing Roberta vein, with intercepts beyond the minor vault returning 24.4 g/t gold and 258 g/t silver over 3.4 m (RO14_349) and 28.3 g/t gold and 239 g/t silver over 2.4 m in hole RO14S_347.

Primero had also discovered a new high-grade vein in the West Block (the Marshall vein), which returned intercepts of 22 g/t of gold and 2 646 g/t of silver over 0.9 m (MSH14_017).

The drilling campaign had also extended the Alexa vein, returning intercepts of 8.9 g/t of gold and 490 g/t of silver over 1.9 m (AL14_126), as well as extending the Santa Gertrudis vein, which returned intercepts of 14.2 g/t of gold and 2 200 g/t of silver over 1.9 m (SG14_012).

The San Jose vein was also extended and intercepts included 6.6 g/t of gold and 470 g/t of silver over 4.m (SJ14_029).

“This [Roberta extension] improves knowledge of the vein extensions eastward in the Central block and is important to the mine life of our platform San Dimas mine,” president and CEO Joseph Conway said on Thursday.

“We also discovered a new vein in the West block, which encourages our geologists that this area of the mine will expand [further] as we continue to invest in exploration. Our strategy at San Dimas remains focused on exploring for high-grade mineralisation in close proximity to existing infrastructure to [reduce] the time between discovery and inclusion in the mine plan,” he noted.

The San Dimas regional exploration programme was focused on new discoveries as well as on surface expressions of the known underground veins.

Primero also reported exploration results from Ventanas, an exploration property close to the San Dimas mine. A drilling programme had demonstrated continuous mineralisation in the San Pedro ore-shoot in the Mala Noche vein, including 11.3 g/t of gold equivalent over 3.2 m, 4.1 g/t of gold equivalent over 10.1 m (MN14_013), 7.9 g/t of gold equivalent over 6.2 m (MN14_016) and 7.1 g/t gold equivalent over 9.7 m (MN14_019A).

“With further success this property could ultimately deliver additional ore to the expanded San Dimas mill,” Conway highlighted.

The Ventanas exploration programme was focused on increasing the existing resource and included drilling on two past producing veins and systematic channel sampling.