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Punta del Cobre District - Alcaparrosa, Carola, Espanola, La Candelaria, Punta del Cobre, Santos, Socavon Rampa, Trinidad |
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Chile |
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Cu Zn Ag Au
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Super Porphyry Cu and Au
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IOCG Deposits - 70 papers
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A series of iron oxide Cu-Au(-Zn-Ag) deposits of varying sizes are located within the ~20 x 5 km, north-south elongated, Punta del Cobre belt to the south of Copiapó in northern central Chile. It includes the Alcaparrosa, Carola, Española, Punta del Cobre, Santos, Socavón Rampa and Trinidad deposits and the much larger La Candelaria (#Location: District centre - 27° 29' 47"S, 70° 15' 6"W).
Other mines include Teresita, Providencia, Granate, Marta Venus, Manto Monstruo, Mantos de Cobre, Resguardo, Atacama Kozan, El Bronce, Las Pintadas, Manuel Antonio Matta, Hernan Videla Lira, Jilguero, Biocobre and La Plata. The Alcaparrosa and Santos mines are combined as the Ojos del Salado operation, and with the Española deposit, constitute the Candelaria Copper Mining Complex. These deposits are described separately within the La Candelaria record, which also includes a geological map of the Punta del Cobre district.
The Punta del Cobre belt lies within an Early Cretaceous continental volcanic arc and marine carbonate back-arc basin terrane whose sequences are intruded by Early Cretaceous granitoid plutons that form part of the Chilean Coastal Batholith. The Punta del Cobre belt deposits are found fringing the eastern margin of the batholith, within (e.g., La Candelaria) or just outside the contact metamorphic aureole (e.g., Punta del Cobre). Andesitic volcanic and volcaniclastic host rocks are intensely altered to biotite-quartz-magnetite. This style of alteration extends much further to the east of the intrusive contact than the metamorphic mineral associations in the overlying rocks that are clearly zoned outboard. Local areas of intense calcic amphibole veining that overprints all rock types occur within the contact metamorphic aureole (Marschik and Fontbote, 2001).
Chalcopyrite mineralisation which crosscuts and thus post-dates all of the major metamorphic and metasomatic assemblages is paragenetically late. Deposits found close to the contact of the batholith and the deeper parts of the sequence in the Punta del Cobre district are characterised by abundant magnetite with associated biotite-quartz alteration, which is overprinted by fracture-controlled calcic amphibole, and chalcopyrite-pyrite mineralisation. Potassium feldspar-chlorite and/or biotite ± quartz plus magnetite ± hematite occur in the intermediate parts of the hydrothermal system. Up-section and, in places, laterally, these assemblages grade into pervasive albite-chlorite-calcite-hematite that are spatially associated with Cu-Au mineralisation in the more distal portions of the system (Marschik and Fontbote, 2001).
Mineralisation is controlled by tectonic structures and their intersection with massive volcanic rocks and overlying volcaniclastic rocks. Isotopic ages of alteration minerals associated with the metallic mineralisation indicates that the bulk of the iron oxide mineralisation formed between 116 and 114 Ma, and the main copper-gold mineralisation between 112 and 110 Ma, and that hydrothermal activity was coeval with both the emplacement of the Copiapó Batholith and regional uplift. They also imply burial during the mineralisation was no greater than 2 to 3 km (Marschik and Fontbote, 2001).
Little information on the geology of individual deposits has been encountered in the publicly available literature.
Deposits other than La Candelaria account for another 120 Mt @ 1.5% Cu, 0.2 to 0.6 g/t Au, 2 to 8 g/t Ag, with the larger deposits producing up to 1.5 Mt of ore per annum.
Marschik and Fontbote (2001) quote resources at individual deposits as follows:
Alcaparrosa - 10 Mt @ 1.4% Cu,
Carola - 20 Mt @ 1.4% Cu,
Las Pintadas - 4.0 Mt @ 1.0 to 1.5% Cu,
Manto Verde - 1.5 Mt @ 1.5% Cu,
Mantos de Cobre - 1.5 Mt @ 1.45% Cu,
Resguardo - 6 Mt @ 1.8 to 2.0% Cu, 0.4 to 0.5 g/t Au, 7.0 g/t Ag,
Santos - 20 Mt @ 1.5% Cu, 0.4 to 0.5 g/t Au, 7.0 g/t Ag,
Socavón Rampa - 25 Mt @ 1.2 to 2% Cu, 0.2 to 0.3 g/t Au, 7.0 g/t Ag,
Trinidad - 15 Mt @ 1.5% Cu, 0.2 to 0.3 g/t Au, 7.0 g/t Ag.
More recent resource estimates for the Ojos del Salado combined Alcaparrosa and Santos mines are listed in the La Candelaria record.
The most recent source geological information used to prepare this decription was dated: 2001.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
Punta del Cobre District - centre
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Selected References:
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Chen H, 2010 - Mesozoic IOCG Mineralisation in the Central Andes: an Updated Review: in Porter T M, (Ed), 2010 Hydrothermal Iron Oxide Copper-Gold and Related Deposits: A Global Perspective PGC Publishing, Adelaide v.3 pp. 259-272
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Marschik R, Fontbote L 2001 - The Candelaria-Punta del Cobre Iron Oxide Cu-Au(-Zn-Ag) deposits, Chile: in Econ. Geol. v96 pp 1799-1826
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Marschik R, Fontbote L 1996 - Copper (-iron) mineralization and superposition of alteration events in the Punta del Cobre Belt, Northern Chile: in Camus E, Sillitoe R H, Peterson R (Eds), 1996 Andean Copper Deposits: New Discoveries, Mineralisation, Styles and Metallogeny Soc. Econ. Geol. Spec Pub no. 5 pp 171-190
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Marschik R, Leveille R A, Martin W 2000 - La Candelaria and the Punta del Cobre district, Chile: Early Cretaceous iron oxide Cu-Au(Zn-Ag) mineralisation: in Porter T M (Ed), 2000 Hydrothermal Iron Oxide Copper-Gold & Related Deposits: A Global Perspective PGC Publishing, Adelaide v1 pp. 163-175
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Marschik R, Singer B S, Munizaga F, Tassinari C, Moritz R, Fontbote L, 1997 - Age of Cu(-Fe)-Au mineralization and thermal evolution of the Punta del Cobre district, Chile: in Mineralium Deposita v32 pp 531 - 546
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Ryan P J, Lawrence A L, Jenkins R A, Matthews J P, Zamora J C, Marino E, Diaz I U 1995 - The Candelaria copper-gold deposit, Chile: in Pierce F W, Bolm J G, (Eds), Porphyry Copper Deposits of the American Cordillera Arizona Geological Society Digest 20 pp 625-645.
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Ullrich T D, Clark A H 1999 - The Candelaria copper-gold deposit, Region III, Chile: Paragenesis, geochronology and fluid composition: in Stanley, et. al., (Eds), Mineral Deposits: Processes to Processing Balkema, Rotterdam pp 201-204
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Williams P J, Barton M D, Johnson D A, Fontbote L, de Haller A, Mark G, Oliver N H S and Marschik R, 2005 - Iron oxide copper-gold deposits: Geology, space-time distribution and possible modes of origin: in Hedenquist J W, Thompson J F H, Goldfarb R J and Richards J P (Eds.), 2005 Economic Geology 100th Anniversary Volume, Society of Economic Geologists, Denver, pp 371-405
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Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge. It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published. While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants: i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.
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