Elementos traza y parámetros cristalinos en casiteritas como indicadores de procedencia: aplicación a la zona de Golpejas (Salamanca)

Abstract

A geochemical study of the detrital cassiterites included in the recent alluvial deposits in the vicinity of the Golpejas mineralisation was undertaken for the following reasons:(l) the further understanding of the geochemical patterns; (2) the application of these patterns as a guide to provenance studies. The results show that minor and trace elements contents in the cassiterites from Regato de los Lentiscos are similar to those obtained for the cassiterites from the Golpejas mineralisation. Otherwise , Ta, Nb, and Fe concentrations in cassiterites from Tirados de la Vega are clearly lower than those from Regato de los Lentiscos and Golpejas mineralisation cassiterites. This pattern is also present in other elements (Ga, Co, Zn, Al, Si, and Pb), although the contents are only slightly lower. These minor and trace element concentrations let us to affirm that the source rock of the two types of detrital cassiterrites is different. A comparative study in Ta, Nb, and Fe concentrations of both types of detrital cassiterites versus Golpejas mineralisation and associated stanniferous vein cassiterites shows very clearly that Regato de los Lentiscos cassiterites come from Golpejas mineralisation and Tirados de la Vega cassiterites come from associated stanniferous veins. So, we can conclude that studies of minor and trace element concentrations can be a useful tool in solving provenance problems. Unit cell studies of different cassiterites corroborate these conclusions.