Las mineralizaciones de Pb-Zn-Ba en el Muschelkalk inferior de los Catalánides

Abstract

The Catalan Triassic is divided into the three characteristie facies of the Germanic Triassic: Buntsandstein, Muschelkalk (Loxver, Middle and Upper Muschelkalk) and Keuper. The base fractures condition the Mesozoic sedimentation, whereby the Catalanid are divided into sedimentary domains, which are separated by transversal faults to the mountain range (ANADON et aL, 1979) (fig. 1). The carbonatic facies from the Catalanid Lower Muschelkalk, Anisien Age, corresponds itself with a ramp depositional environment, in which the paleokarstic levels are frequent, the importance of which development, number of Ihe afected paleokarstic surfaces and materials vanes in accordance with the location of the different domains (MARZO et al., 1983). In this context you can find numerous traces of Pb-Zn-Ba stratabound mineralizations (SAGRISTA et al., 1980, and MATA, 1982) associated with paleokarstic surfaces or algal-mats leveIs (fig. 2). me associated karst mineralizations are singenetic with the karstic filling, Anisiense age. Ihe algal-mats, rich in organic matter, present a high level of Pb-Zn-Ba, Uds elements themselves accumulated into the algal facies while this build up. As fon the origin of this deposits a model named supergen singenetic by AMSTUTZ (1962) is proposed, in `which Ihe minerals themselves deposited at selisame time which the sediments and the mineralizants elements are supergen source. The main contribution of the elements comes from the continent lixiviation (strong anomalies in Pb, Zn, Ba, Cu in the Paleozoic Age) (CASAS, 1979 and FONT, 1983).