Iron Oxide Copper-Gold in South America
4 to 13 June 2007
Porter GeoConsultancy continued it's series of International Study Tours by visiting a selection of the most significant Iron Oxide Copper-Gold and related deposits in the Carajás District of Brazil and and the Coastal Cordillera of Chile, supported by classroom & field workshops.
The tour commenced in Marabá, Para state, Brazil on the evening of Sunday 3 June and ended in Santiago, Chile on the evening of Wednesday 13 June, 2007.
Participants had the option of taking either the full tour -or- any block of 4 or more days up to the total number of days on the Tour, as suited their availability and interest.
The tour program was as follows:
Cristalino, chalcopyrite-pyrite and magnetite mineralised stockwork and breccia within a shear zone cutting magnetite-amphibole altered Neoarchaean mafic volcanics ..... Monday 4 June, 2007.
Sossego, a deposit cluster in a broad zone of shearing, with two superposed Cu-Au mineralising events, an ~2.71 to 2.68 Ga magnetite-albite-actinolite, and an ~1.90 to 1.88 Ga potassic and chloritic altered phase ..... Tuesday 5 June, 2007.
Igarapé Bahia, a gossan/lateritic Au, and supergene Cu-Au deposit developed over a semicircular annulus of hypogene Cu-Au mineralised hydrothermal breccia ..... am Wednesday 6 June, 2007.
Alemão, a down-faulted segment of the Igarapé Bahia breccia that continues to depth with Cu sulphides, pyrite, magnetite, amphibole, chlorite, siderite and ankerite ..... pm Wednesday 6 June, 2007.
Salobo, a 4 km x up to 600 m wide, steeply dipping, composite of massive replacement lenses of magnetite, fayalite, grunerite, almandine, biotite and Cu sulphides following the mylonitic foliation of the enclosing Cinzento Shear Zone ..... Thursday 7 June, 2007.
Some participants left the tour after the Brazilian segment. On the morning of Friday 8 June, the day following the Saloboo visit, the on-going group flew from Carajás via Brasilia, São Paulo and Santiago to Copiapo in northern Chile, arriving in the afternoon of Saturday 9 June. There they were joined by new starters taking the Chilean leg only.
Andean Overview Workshop, an overview workshop was run late on Saturday 9 June, 2007 in Copiapo, Chile at the beginning of the Andean segments of the tour to provide a context to the tectonic, geological and metallogenic setting of the IOCG deposits of the Andes and descriptions of other deposits in the region not on the itinerary. The workshop was led by Dr Carlos Arevalo of the Chilean Servicio Nacional de Geología y Minería (SERNAGEOMIN) ..... afternoon and evening of Saturday 9 June, 2007.
Punta del Cobre district - Field Workshop, which provided a context setting to the major Candelaria deposit and an impression of the anatomy of an important IOCG district, the geologic, structural and metallogenic setting, the distribution of alteration and different styles of mineralisation. The workshop was also led by Dr Carlos Arevalo ..... Sunday 10 June, 2007.
Mantoverde, ~100 km north of Copiapo in northern Chile, comprising chalcopyrite-pyrite in fault controlled, specularite-dominated, tabular breccias and stockworks, hosted by Cretaceous andesites ..... Monday 11 June, 2007.
La Candelaria, ~20 km south of Copiapo in northern Chile, occurring as disseminated and veined chalcopyrite, pyrite and gold in volcanic and hydrothermal breccias and replacing early massive magnetite ..... Tuesday 12 June, 2007.
Mantos Blancos, some 45 km NE of Antofagasta in northern Chile, where breccia, with disseminated and stockwork sulphide mineralisation is hosted by albitised and hematite altered Triassic felsic volcanic rocks ..... Wednesday 13 June, 2007.
The tour was planned, organised, managed and escorted by Mike Porter of Porter GeoConsultancy Pty Limited. See the photo album, linked above, for more detail. Image upper left: scene in the Coastal Cordillera, northern Chile.
|A PorterGeo International Study Tour|