Estudio de inclusiones fluidas de las mineralizaciones epitermales de Ag.Baritina.metales de base de Hiendelaencina y de Baritina de Atienza (Sistema Central Español)

Abstract

Fluid inclusion studies on quartz and barite samples from the Hiendelaencina Ag-base metals epithermal deposit (late Hercynian) suggest that this mineralization was formed during four hydrothermal stages. Ore stage I was characterized by aqueous-carbonic fluids from which pyrite and arsenopyrite were precipitated. The interaction between probably magmatic-derived fluids (aqueous solutions; Th = 320 – 200º C, 12 eq. wt. % NaCl) and meteoric waters (of lower temperature and salinity) caused a generalized decrease in both, T and salinity (from 12 eq. wt. % NaCl to 3 eq. wt. % NaCl), thus probably inducing the precipitation of Cu and Zn minerals (ore stage 11). Ore stage 111 (silver stage) was characterized by the interaction between fluids of low temperature and contrasted salinities (Th = 100 – 150º C; 3 eq. wt. % NaCl to 18-22 eq. wt. % NaCl). A final and «barren stage » (stage IV) resulted in the precipitation of a late generation of quartz and barite.