Miramar firms up Cuban play

The final feasibility study of the Mantua copper-gold deposit in Cuba is expected this month.

Miramar Mining (TSE), which owns half of the property, says the study is likely to call for a 2-year period of gold leaching, followed by a copper mining operation with a mine life of nine years. (The remaining half of the deposit is owned by the Cuban government.)

Last May, Miramar transfered its Cuban properties to its 51%-owned subsidiary Northern Orion Explorations (VSE) in exchange for 24 million shares of Northern Orion. The deal affects both the Mantua property, 220 km southwest of Havana, and the Delita gold property on the Isle of Pines, off Cuba’s southwestern coast.

Recent drilling has concentrated on the shallow “gold zone,” the leached cap of the deposit, where 65 holes were drilled to define minable reserves. The minable reserve in the gold zone is calculated at 2.04 million tonnes grading 1.44 grams gold and 11.5 grams silver per tonne.

Preliminary resources on the “copper zone,” a supergene-enriched, lower structure, are estimated at 22.6 million tonnes grading 1.01% copper. This figure includes 11.4 million tonnes of higher-grade mineralization with a grade of 1.83% copper and lower-grade mineralization totalling 11.2 million tonnes with 0.17%.

Of this material, 15.2 million tonnes are classified as minable. A reserve of 6.2 million tonnes is classified as “mill grade,” with an average copper tenor of 2.8%. (These ores will be conventionally milled.) Another 5.2 million tonnes, grading 0.53%, will be heap-leached after crushing. A further 3.8 million tonnes grading 0.11% are “dump-leach” grade, which will be leached without crushing.

Davy International of Toronto is preparing the final feasibility study.