Focus' claims total 1,200 hectares and cover the historic Minas Chanca high-grade epithermal silver mine located in the central Peru mineral belt, approximately 20km north-west of Buenaventura's Uchucchacua Mine, which reportedly produced 10.5M oz of silver in 2009.
The property was acquired 100% by Focus through staking in 2009 as part of its aggressive on-going project acquisition strategy targeting historic producing properties with untested exploration potential.
The Agreement with Buenaventura will offer Focus a foothold in any future production scenario in a historic, rich, yet unexplored silver mining district. Should exploration be successful in delineating resources at Minas Chanca, the project could have operational synergies with Buenaventura's Mallay Ag-Pb-Zn Project, located some 17km south, where production is slated for 2011.
Location
The mine is located midway between the towns of Oyon and Cajatambo, some 160km north of the Peruvian Capital, Lima, at altitudes of 4,400 -- 4,900 m a.s.l. The property is located within the central Peru polymetallic belt, known for its silver-rich base metal deposits, many of world class category (Cerro de Pasco, Uchucchacua).
History
References to mining at Minas Chanca date back to 1712 during Colonial times. Initially ore was produced by open pit along the Discubriadora vein, which was known for its richness in silver. Spectacular high grade silver in "boyos" (shoots) were exploited. However the most important vein was the Candelaria vein, which during early production reportedly yielded grades of 50 to 75 oz/t of silver.
The District of Oyon, where Chanca is located, has yielded at least 40 million ounces of silver from a swarm of epithermal veins. The area was known for its spectacular bonanza silver grades within rich pockets or "boyas" of ruby silver. The mine has remained unexplored since its closure in the 1980s and has never been drilled. Potential exists to find additional resources along strike and underneath known mined veins as well as within new structures.
More recently a Peruvian mining company worked the mine during the 1970s and 1980s until its closure in 1985. The last available resource calculation* available was by INGEMMET in 1980, who reported a resource of 503,300 t grading 13.42 oz/t Ag, 2.26% Pb ("high grade") and 112,588 t grading 3.86 oz/t Ag, 0.92% Pb ("low grade"). *The reader is cautioned that this resource estimate is historic in nature and is mentioned for information purposes only. The mine is believed to have continued production for several years after this resource estimation and Focus has not completed sufficient work to verify whether this resource exists or was mined or partially mined out. The resource was completed prior to NI 43-101 and as such it cannot be relied upon.
Geology
Production was from at least 20 veins and splits of various orientations that cross-cut lower calipuy andesites and volcanic breccias. The majority of ore came from 3 principal veins, Candelaria, Tarazca and Santo Toribio, which trend N050E. Other veins included the Prescilda, Shirley and Yanacelli veins which have a dominant N70-85W trend. The highest grades of silver were reported to occur mainly on the intersections of these structures. Mine levels span approximately 300 vertical meters, and past production occurred via a system of galleries, cross-cuts and drives. Vein mineralogy is dominated by argentiferous galena, proustite and pyrargyrite within a gangue of quartz, pyrite, calcite and rhodochrosite.
Work by Focus
Although underground galleries are inaccessible, sampling was restricted to the old mine dumps. Four grab samples of dump material gave the following results and confirm the high silver content of the mineralization.
|
Ag |
Au |
Cu |
Pb |
Zn |
SAMPLE |
oz/t |
ppm |
ppm |
ppm |
ppm |
17322 |
14.98 |
0.329 |
2530 |
2.18 |
1.73 |
17323 |
13.73 |
0.16 |
492 |
4.06 |
1 |
17324 |
10.83 |
0.25 |
524 |
3.92 |
8180 |
17325 |
91.31 |
0.692 |
2040 |
14.75 |
2.47 |
Work Program
Subject to the granting of the usual permissions, Buenaventura's work program will comprise geological mapping, sampling, trenching and drilling, including rehabilitation and sampling of underground adits and tunneling.
Terms of the Agreement with Buenaventura
Under the terms of a Letter of Intent, Buenaventura can earn up to a 75% interest in the claims by spending US$3 million in exploration and development over a period of three and a half years from the issuance of the necessary permits. During the first phase, Buenaventura has committed to earning a 50% interest in the property by spending no less than US$1 million in exploration within 18 months, which will include a total of 3,000m of drilling. To earn an additional 25% interest (total 75%), Buenaventura has the option to complete US$3 million in exploration and development expenditures within 3.5 years.
Buenaventura will also have the option to acquire the remaining 25% participating interest of Focus. The purchase price will be defined based on resources outlined in a NI-43-101 compliant technical report made after Buenaventura invests the US$3 million. A formula for the calculation of sale price and for any resources defined during any future production will be negotiated and detailed in a definitive agreement.
Chanca Photo Gallery
