USMX active in Puerto Rican copper-gold deposit

An advanced copper-gold deposit in Puerto Rico will be further tested this year by a drilling and metallurgical program funded by USMX (NASDAQ).

The company recently acquired an approximate 50% equity interest in a private company which, in turn, holds the exclusive exploration permit for the advanced porphyry deposit. Situated in the central highlands of west-central Puerto Rico, Calo Abajo was previously explored by a unit of Amax in the early 1960s.

The major outlined a near-surface reserve amenable to open-pit mining. Estimates are 70.6 million tons grading 0.83% copper and perhaps about 0.01 oz. gold per ton (little attention was paid to gold at the time of the calculation). This reserve is based on 98,400 ft. of drilling in more than 135 holes, with most of the holes spaced 164 ft. apart.

USMX is funding a drill program focused on a smaller, supergene-enriched deposit with higher copper and gold grades occurring above the primary mineralization.

Core samples will be obtained for metallurgical testing based on a view that the supergene mineralization (primarily chalcocite) may be amenable to leaching and solvent extraction-electrowinning.

USMX intends to work closely with its 50%-owned private company over the coming months to complete a feasibility study and obtain permits, if warranted.