Following a two-month shutdown during unusually severe winter conditions, mining has resumed at Yamana Resources‘s (YRI-T) high-grade Martha underground silver mine on the Bacon property in the southern Patagonia region of Santa Cruz, Argentina.
So far, about 1.5 million oz. silver-equivalent have been produced from portions of three bonanza-grade pockets in the Martha vein system.
Yamana has lowered this year’s production estimate at Martha to 2.9 million equivalent oz. from its original estimate of 3.25 million. To date, ore grades have averaged 520 oz. per tonne silver-equivalent, compared with 650 oz. per tonne in the original development plan.
Yamana attributes the production shortfall to the upper, oxidized portion of bonanza pocket 1, which was expected to house about 1.6 million equivalent oz. at a grade of 880 oz. per tonne. It now seems that the block contains about 1 million oz. at a grade of 680 oz. per tonne.
Offsetting the shortfall are some 450,000 equivalent oz. that were mined from an area that hasn’t been drilled and is located between pockets 2 and 3. This material is not included in Martha’s original reserve estimate.
Faced with the lower production and depressed silver prices, Yamana is discussing with its lenders an extension of the maturity date (Dec. 31) on the project’s financing facility.
The company is working with its mining contractor to increase productivity and reduce ore dilution. A surface drilling program, aimed at expanding Martha’s known reserves and supporting ongoing mining will begin shortly.
The Martha mine is situated on the Veta Martha silver shoot, a 200-metre segment of the regionally extensive Veta Martha fissure vein system.
At least four high-grade, near-surface bonanza pockets have been found, each of which remains open in at least one strike direction and at depth below 35 metres. At a cutoff grade of 160 oz. equivalent silver per tonne, these high-grade pockets are thought to contain almost 4 million oz. equivalent silver in only 7,800 tonnes of material.
Outside the four known pockets, drilling has indicated that resources at Bacon are 4.7 million equivalent oz. averaging 42.4 oz. per tonne.
A four-phase mining plan at Martha aims to expand the lower-grade silver resources and employ a small mill to produce concentrates of shippable grade.
An in-house study suggests that the Martha vein system remains incompletely tested and has exploration potential for 40 million equivalent oz.
Be the first to comment on "Martha Mine thaws out"