The Cerro Verde Tour group on the road back to Arequipa. From left: Wendell Terrones (Rio Tinto Exploration, Peru); Henrry Motta (Rio Tinto Exploration, Peru); Atsuhiro Kuroda (Sumitomo, Japan); Frederick Sanchez (BHP Mineral Exploration, Peru); Suziany Rocha de Souza (Rio Tinto Exploration, USA); Michel Moisy (BHP Mineral Exploration, Peru) Sergio Barassi (Bafermin, Chile); George Steele (Rio Tinto Mining and Exploration, Chile); and Song Zhang (Rio Tinto Minerals Exploration, China). Image by Mike Porter.
Cerro Verde was the first visit on the tour itinerary. However, early on the morning of the previous day, Monday 4 June, members of the group had rendezvoused at Lima airport to fly to Arequipa in southern Peru. Most of the remainder of that day was spent undergoing comprehensive medical examinations at a specialist clinic to generate reports for consideration by medical staff at the Las Bambas, Toromocho and Antamina mines as to whether the participants were fit for activity at the high altitudes at which these mines are located. These tests had to be performed in Peru, at a clinic approved by the respective companies.
Early on the morning of Tuesday 5 June, the group departed their hotel in Arequipa to drive to Checkpoint China on the road to Cerro Verde where they underwent an induction before continuing on to the Geology Office. There they received a comprehensive briefing by Eddy Benavente and Miguel Soncco of Sociedad Minera Cerro Verde on the setting, geology and mineralisation of the deposit and surrounding district. This was followed by inspection of core from representative drill holes through the key deposits, and finally an overview of the main open pit. No photography was permitted on site. In mid to late afternoon, the group returned to Arequipa.
The Paleocene Cerro Verde deposit cluster is characteristic of the porphyry deposits of the central Andes in northern Chile and southern Peru, developed over a basement of Proterozoic metamorphic rocks that are overlain and cut by Mesozoic to Cenozoic felsic intrusive, volcanic and siliciclastic sedimentary rocks with only minor carbonates. It is also characterised by tourmaline and silica breccias and a well developed supergene sulphide blanket overlying lower grade hypogene ore and mineralisation within intrusive felsic hosts.