Summary of the mining and exploration history of AntaKori and the Hualgayoc district:
Mining and Exploration Carried Out
Mined a hill at Chupicayacu (Quechua chupica - red, yacu - water), probably the Rio Colorado (AntaKori).
Hualgayoc silver mines discovered. From 1771-1956 they produced 1,000-1,500 tonnes (32-48 million ounces (Moz)) silver, with some estimates as high as 4,000 tonnes (130 Moz).
Alexander von Humboldt
Visit to Hualgayoc district by Alexander von Humboldt.
1859 & 1868
Visits to Hualgayoc by Antonio Raimondi. Most of the mines were abandoned, having exhausted the silver oxide ores.
1887 & 1893
Introduction of smelting (1887) and sulphide leaching (1893) enabled sulphide ores to be processed and reactivated silver production in the Hualgayoc district. In 1904 there were 5 small smelters and 8 leaching plants.
Consolidation of companies
Consolidation of ownership of Hualgayoc district in 3 main companies. Compañía Minera Italía (1908), which became the Sindicato Minero Santa María de Hualgayoc (1927). Compañía Socavón Purgatorio (1908), became the Compañía Explotadora Minas de San Agustín (CEMSA) (1940), and the Compañia Minera Colquirrumi S.A. in 1970. The third miner was Sr. Eloy Santolalla. There were also many small miners.
Late 19th to late 20th century
Small scale mining of massive sulphides at Sinchao (Antakori) to produce Cu, Au, Ag, Pb and Zn. Ore processed in plants at Tingo, Sinchao and Maria Eugenia.
Northern Peru Mining & Smelting Corporation
Diamond drilled the Tantahuatay and Sinchao areas and identified a moderately large, low grade copper body.
Carried out exploration (details not known).
Cerro de Pasco Corporation
Optioned 384 ha of concessions at Tingo-Sinchao. Carried out a topographic survey, geological mapping, mapping and sampling of all small mines, a self potential (SP) survey which identified 16 anomalies, magnetic survey, trenching, and drilled 4 diamond drill holes in 1964 (2 at Maria Eugenia, 1 at Cleopatra, 1 unknown). Estimated potential for 2 million tons at 2.5% Cu and 1-1.5 opt Ag. They described mineralisation in metasomatic replacement bodies along a limestone-intrusive contact.
Cerro de Pasco Corporation
At Azufre (Tantahuatay) staked 17,000 ha. Carried out helicopter reconnaissance, geological and alteration mapping, soil and rock geochemistry, IP survey.
Servicio de Geologia y Mineria (now INGEMMET)
Soil sampling program for porphyry copper deposits over 10 km sq on a 200 m grid at Tantahuatay and Sinchao. Found 7 anomalies with the largest at Quebrada Tantahuatay.
Regional exploration program.
Drilled 2 vertical holes 100 m south of the Inquisicion pit.
Exploration for massive sulphide bodies. Identified an area of 400 m by 100 m with 3-5% Cu in an ore-bearing horizon.
Southern Peru Copper Corporation (Asarco) and Buenaventura.
Explored Tantahuatay and drilled 30 diamond drill holes.
El Misti Gold Limited, Canada (El Misti Gold S.A., Peru)
Explored Sinchao. Soil grid 50 m x 50 m, geological mapping, 22.1-line km of IP-resistivity, 23.3-line km of ground magnetics. Drilled 22 x reverse circulation holes for 3,274.50 m in two phases in 1997-98, and 10 x diamond drill holes for 8,450.75 m in 1998.
Andean American Mining Corp., Canada (El Misti Gold S.A., Peru)
Change of company name on share consolidation. No drilling carried out. NI 43-101 technical report by Jaramillo (2006).
Sinchao Metals Corp., Canada (Compania Minera Sinchao S.A.C., Peru)
Andean American was acquired by Sinchao Metals Corp. 3D IP and ground magnetic surveys, geological mapping, geochemical sampling, trenching. Drilled 38 x diamond drill holes for 9,503.41 m in 2007-08. Released a NI 43-101 mineral resource estimate in 2008 (Jaramillo, 2008). In 2011 the resource was invalidated when the company announced that it did not own four of the tiles where 40% of the resource was located, and the project was written off.
Gold Fields Limited
Started open pit mining of copper-gold sulphides at Cerro Corona.
Compañía Minera Coimolache S.A.
Started open pit mining of a gold oxide orebody at Tantahuatay adjacent to the southern side of Sinchao (Antakori).
Southern Legacy Minerals Inc., Canada (Southern Legacy Peru S.A., Peru)
Southern Legacy acquired Sinchao Metals Corp. and renamed the project Antakori in 2012. No new exploration. Filed a new NI 43-101 mineral resource estimate in 2012 (Wilson, 2012).
Regulus Resources Inc., Canada (Southern Legacy Peru S.A., Peru)
Regulus Resources amalgamates with Southern Legacy Minerals.
Agreements signed with Compañía Minera Coimolache S.A. and Compañía Minera Colquirrumi S.A. for mutual rights of access, expansion and collaborative exploration around Antakori.
Phase I diamond drill program of 34 holes (30 holes drilled by Regulus and 4 holes drilled by Coimolache partially onto Regulus ground) for 19,601.23 m.
Phase II diamond drill program.