Processing operations were suspended during the third quarter of 1999 to allow additional tailings capacity to be constructed. During this period, mine development was accelerated and remedial maintenance was carried out on the mine and process plant equipment. Production under Hecla's control commenced on October 1, 1999. It lies in the Botanamo greenstone belt of the Precambrian Guayana Shield and is hosted by the Caballape Group of volcaniclastics. The formations most likely date from Archean to Proterozoic age and consist primarily of intermediate volcanics with subordinate metasediments.
Gold occurs both as free particles in quartz and attached to or included in pyrite.
Locally, gold is also seen on chloritic partings. Hecla believes the results of that program confirm that ore-grade mineralization extends to depths below the levels to which the current mine reserves have been delineated. In addition, Hecla controls nine other exploration concessions near the La Camorra mine encompassing 8,000 hectares. Ore is extracted from the stopes using rubber-tired equipment and hauled to the surface in mine haulage trucks. Subeconomic material is used to backfill and stabilize mined-out stopes.