Mineralizaciones estratoligadas de scheelita en la Faja Pirítica del Suroeste Ibérico

Abstract

In the Bajo Corumbel region (La Palma del Condado, Huelva), scheelite mineralizations occur related to carboniferous beds belonging to the Iberian Pyrite Belt. They are best located in the same stratigraphic horizon as the calcarenitic rock of the Culm bottom, although the mineralizations appear occasionally in other different stratigraphic positions (PQ y CVS). The mineralizations consists of garnetiferous quartzites and chlorite rich gametites containing variable amounts of scheelite, arsenopyrite, fluorite, topaz and sulphides. Sn, W y As contents come respectively up to 7000, 11000 y 14000 ppm. There exist also geochemical anomalies in Cu, Zn, Pb, Ag, Bi, V, Coy F. Country rocks have been affected by several deformation phases during the Hercynian Orogeny. A low to very low grade, regional metamorphism is produced related to main deformational event. Mineralized beds not show internal deformation patterns. There is also Sn-W vein mineralizations in the region, which geochemical pattern are similar to scheelite stratabound deposits, and also similar to others vein deposits in the Iberian Massif. Scheelite stratabound deposits, controversial in origin, have been previously described elsewhere in the Iberian Massif. In the case of Bajo Corumbel ones, a metasomatic genesis is proposed, related to the same hydrothermal fluids which originated the associated vein deposits according to the following evidences: mine-ralogical and geochemical evidence, textural and spatio-temporal relationships and close relation with hydrothermal alteration.