The company, which like a lot of its peers has had a roller-coaster year on the market, said drilling on four targets would be the first time a rig has been on the site since 2010.

"We are excited to be drilling at Miguel Auza for the first time since 2010 on what we believe is an under-explored part of the northern Fresnillo silver trend, one of the richest silver belts in the world," said Excellon senior vice-president geology, Ben Pullinger.

"Our recent exploration has encountered strong indicators at surface that suggest we are above the productive part of an epithermal system.

"This drill program is intended to test mineralized veins and structural targets for the deeper mineralized shoots typical of this prolific belt."

Excellon completed 25 line kilometres of induced polarization (IP) surveying, plus mapping and sampling, on the four initial targets. It says 130sq.km of "detailed mapping" across the 14,000-hectare property has identified seven additional targets for follow up.

Historical diamond drilling results were "believed to be indicative of a larger epithermal system", the company said. The results include high silver and decent zinc and lead grades over narrow intervals.

"The company believes that narrow high-grade intersections historically reported on the property are indicative of a distal part of a larger epithermal system carrying high grades over greater widths which will be targeted as part of this program," Excellon said.

"The objective of the initial drill program is to drill test targets developed from surface mapping, IP surveying and structural work conducted since mid-2017 at El Cobre, Abejas, Carmen-Lechuzas and Lomo de las Minas."

Hecla Mining has the San Sebastián mine 35km to the north-west and along strike from Miguel Auza on the Fresnillo belt.

Excellon has an 800 tonnes-per-day processing plant and 650tpd ball mill at Miguel Auza (and a smaller ball mill on "standby").

It has been producing silver from the high-grade Platosa mine in Durango since 2005.

Excellon is trading around the same level it was this time last year (circa C$1.50), but has been as high as $2.30 in the interim. Its current market capitalisation is C$148.77 million.