Chilean Iron Belt
Iron oxide-apatite, iron oxide copper gold ore deposits (IOCG) and manto-type copper and silver are the main types of deposits. Iron-apatite and IOCG are considered to have different origins. Manto-type deposits are concentrated in the northern part of the belt and are chiefly emplaced on rocks of La Negra Formation.
The ores of the Chilean Iron Belt formed in separate pulses in the Cretaceous period as result of magmatic and hydrothermal processes. At least part of the iron oxide-apatite rock originated from molten iron in the form of lava, tephra. and intrusions. Thus iron oxide apatite magma cooled into rock variously from surface volcanoes to depths of 10 km over even more.
Some geologists have speculated that a large meteorite impact in the Pacific during the Cretaceous period may have set in motion a series of tectonic changes that led to the formation the ores.
Iron mines along the Chilean Iron Belt
- El Carmen
- Los Colorados
- El Algarrobo
- El Tofo (defunct)
- El Romeral
References
- ^ Barra, Fernando; Reich, M.; Selby, D.; Rojas, P.; Simon, A.; Salazar, E.; Palma, G. (2017). "Unraveling the origin of the Andean IOCG clan: a Re-Os isotope approach" (PDF). Ore Geology Reviews. 81 (1): 62–78. Bibcode:2017OGRv...81...62B. doi:10.1016/j.oregeorev.2016.10.016.
- ^ Simon, Adam C.; Knipping, Jaayne; Reich, Martin; Barra, Fernando; Deditius, Artur P.; Bilenker, Laura; Childress, Tristan (2018). "Kiruna-Type Iron Oxide-Apatite (IOA) and Iron Oxide Copper-Gold (IOCG) Deposits Form by a Combination of Igneous and Magmatic-Hydrothermal Processes: Evidence from the Chilean Iron Belt". In Arribas R., Antonio M.; Mauk, Jeffrey L. (eds.). Metals, Minerals, and Society. Society of Economic Geologists Special Publication. Vol. 21. pp. 89–114. doi:10.5382/SP.21. ISBN 9781629493084.
- ^ Travisany, Vinicio; Henríquez, Fernando; Nyström, Jan Olov (1995). "Magnetite lava flows in the Pleito-Melon District of the Chilean iron belt". Economic Geology. 90 (2): 438–444. Bibcode:1995EcGeo..90..438T. doi:10.2113/gsecongeo.90.2.438.
- ^ Tornos, Fernando; Hanchar, John M.; Munizaga, Rodrigo; Velasco, Francisco; Galindo, Carmen (2020). "The role of the subducting slab and melt crystallization in the formation of magnetite-(apatite) systems, Coastal Cordillera of Chile". Mineralium Deposita. 56 (2): 253–278. doi:10.1007/s00126-020-00959-9. S2CID 212629723.
- ^ Oyarzún, J.; Oyarzun, R.; Lillo, J.; Ménard, J.J. (2012). "May a large asteroid impact in the Pacific have triggered a cascade of tectonomagmatic events leading to formation of the Mid-Cretaceous Chilean Iron Belt?". Geotemas. 13: 1915–1918.