Location
The Puchuldiza Project is located in the high Andean Plateau (Puna) of northernmost Chile (Figure 1), close to the Bolivian border at an altitude 3,800 to 4,200 meters above sea level. Central UTM coordinates of the property are 7,854,000 North and 504,500 East. The project lies approximately 230 kilometres NW from the port city of Iquique, capital city of the region, and 18 kilometres west of the small Chile border town of Colchane. Access to the area is via good paved roads that join Iquique through Huara with the village of Colchane.
Mineralization is related to a low sulphidation epithermal system developed in acidic to intermediate volcanic and volcanoclastic rocks of Upper Tertiary to Quaternary age (Figure 2). Alteration is extensive in the area, consisting of a central silicified nucleus, represented by the sinter and underlying silica replacements, surrounded by an extensive halo of argillic alteration, characterized by a low temperature assemblage of illite and/or illite-smectite, and an external zone of chloritic alteration grading to fresh rocks. Solfataric alteration, related to a Quaternary volcanic centre, is extensive in the higher parts of the zone.
Gold mineralization coincides with a complex system of veins, veinlets, breccias, stockworks, and hydro-fractures that generate sub-horizontal bodies hosted in the sinter and in the underlying breccias and basement volcanic rocks, and also in restricted sub-vertical vents, both intimately related to the silicic alteration. These bodies consist of fine bands of opal and chalcedony, with disseminations, bands, and veinlets of pyrite, marcasite, arsenopyrite, occasional free gold, stibnite, native antimony, cinnabar, orpiment and realgar.
1968-1981: The Chilean Geothermal Committee, a government agency, with the assistance of the Japan International Cooperation Agency (“JICA”) initiated exploration activities aimed at evaluating the geothermal potential of the area. They actively explored the area until 1981 and conducted geological mapping, geochemistry, geo-thermometry and drilled 6 geothermal holes down to a maximum depth of 1,147 meters. Results were not conclusive and the project was abandoned.
1990’s: Early in 1990, Coeur d’Alene Exploration (CDE) acquired the mining rights from Freeport Chile, who had started precious metal exploration in the area. Freeport completed surface geological mapping and a 25 x 30 meter rock geochemical grid over the sinter (samples assayed for Au, Ag, Cu, Mo, As, Sb, Hg, Tl, and Ba). CDE continued the exploration activities with:
2001: In November 2001, CDE optioned the project to Barrick Chile whereby Barrick committed to spend a minimum of US$2,250,000 in exploration activities within a period of five years in exchange for a 75% interest in the project.
2002-2006: Barrick Chile explored the project and completed:
2007: In May 2007, Coeur and Barrick agreed on an extension of the option until November 2008. The extension was granted in return for fulfillment by Barrick of US$250,000 in pending expenditures committed for the 2001 – 2006 period and for fulfillment of additional expenditures of US$200,000 in exploration in the property. By the end of the extension period Barrick had not met the committed expenditures and was thus officially notified by Coeur of the expiration of the option.
2010: In a public deed dated May 14, 2010, that was signed, before the Notary Public, Mara Achar¡n Toledo, repertoire N° 13.921, between Coeur South America, Chile Agency; and Minera Southern Legacy Chile Limitada and Southern Legacy Minerals Inc., an unilateral option to purchase agreement whereby Coeur irrevocably offered to sell to MSL the claims and all of the rights inherent to them. In order to earn a 100%-ownership, Minera Southern Legacy Limitada paid Coeur South America US$1,500,000 plus 500,000 shares of SLM common stock.
2011: In May 2011, a NI 43-101 compliant resource estimate by Sociedad Cartografica Limitada (“Cartografica”) was completed indicating an inferred resource of 686,000 oz of Au at a grade of 0.71 g/t in 30.07 Mt (using a 0.5 g/t cut-off).
2014: In October 2014, Southern Legacy Minerals was amalgamated into Regulus Resources Inc.
On November 7, 2011 Southern Legacy Minerals completed the following NI 43-101 compliant technical report at the Puchuldiza Project. The resource estimate was completed by Antony J. Amberg of Sociedad Cartografica Limitada. The 43-101 estimate is based on 6,097 metres in 35 core drill holes.
Cut-Off Grade Au (g/t) |
Tonnes (x1,000) |
Au (g/t) |
Au (K oz) |
---|---|---|---|
0.7 | 13,029 | 0.85 | 356 |
0.5 | 30,072 | 0.71 | 686 |
0.3 | 40,716 | 0.63 | 827 |