Summary
The La Encantada Silver Mine is a producing underground mine located in Northern Mexico approximately a 1.5 hour flight from Toreon and comprises 4,076 hectares of mining rights and surface land ownership of 1,343 hectares. The closest town, Muzquiz de Boquillas del Cármen, is 45 kilometres away via dirt road. (Apr/12).
SILVER and LEAD mine.
* Technical report (Jan/09) on document Pa715153.PDF, 134 pp.
* Technical report (Dec/08) on document Pa709218.PDF, 113 pp.
* Technical report (Mar/08) on document Pa611619.pdf
* Technical report (Jan/08) on document Pa580842.pdf, 117 pp.
* Technical report (Dec/06) on document Pa441983.pdf; 37 pp.
Geology
The elevation of the area varies between ± 1,800 m (Maria Isabel shaft and/or fault) and ± 2,300 m (at the San Javier breccia outcrop) above sea level (a. s. l.).
The La Encantada Silver Mine is located in Lower Cretaceous limestones (Albian) in a regionally folded and thrusted sequence of Mesozoic carbonates and interbedded with shale. This folded complex forms part of the morpho-tectonic province of the Sierra Madre Oriental which can be compared to the Rocky Mountains in BC and Alberta.
Mineralization at La Encantada is a typical assemblage of metasomatic deposits with a high content of silver and lead. This mineral assemblage has been affected by a long process of oxidation and secondary enrichment. The most important mineralization consists of unconsolidated massive concentrations of oxides including hematite, limonite and other iron oxides as well as carbonates and sulphates, including the minor presence of zinc oxides. Silver and lead represent the main economic minerals within the oxidized deposits at La Encantada. Silver mineralization occurs as argentite and native silver. Lead mineralization is present as carbonates (cerussite) and sulfates (anglesite) and other oxides. (Jan/08)
The mineralization occurs predominantly in Albian limestones of the Aurora Fm. and belongs to the high-temperature, carbonate hosted, Ag-Pb-Zn-(Cu) skarn deposits (Megaw et al., 1988) type. The mineralization occurs in chimneys, contact bodies, mantos, and irregular veins. Some 34 minerals of 9 groups have been recognized. They are all supergenic enrichment minerals. The predominant silver mineralization occurs as argentite, acanthite, galena and some native silver.
Operations
La Encantada Silver Mine has been in operation since the 1950s, with intense extraction and processing
operations from the early 1970’s. The mine was initially developed from the shafts as a conventional operation with rail haulage levels, and utilizing standard rail-bound loading and hauling equipment. Subsequently, La Encantada Mine has been converted to a mainly trackless operation, although rail haulage is still used on a few of the deeper levels of the mine.
La Encantada Silver Mine consists of an industrial complex that includes underground silver/lead/zinc mining, a flotation ore processing plant, water wells and pipeline, airport, housing, camp facilities and a new cyanidation plant under construction to process silver tailings. The La Encantada mine was operated by Peñoles for a period of about 25 years, until June 2002.
Its production, by Peñoles records, amounts to over 80 million ounces of silver and over 1.3 billion pounds of lead. La Encantada is by no means exhausted; its geologic potential remains to be fully explored. Several zones within the mine area have been identified that may contain significant mineralization, such as Breccia La Escalera, Breccia Milagros, Breccia San Javier and others that enable the operators to increase La Encantada’s production. (Jan/08)
The La Encantada Silver Mine consists of a newly constructed 3,750 tpd cyanidation plant, an old 1,000 tonnes per day flotation plant (currently in care and maintenance), a village with 180 houses as well as administrative offices, laboratory, general store, hospital, schools, church, airstrip and all infrastructure required for such an operation. During the third quarter of 2011 the plant constantly achieved 4,000 tpd. (Nov/11)
