Analyse des phases fluides associees a la genese des amas sulfures et des filons Au-Ag de la province de Taxco-Guanajuato (Mexique).
Por:
Charoy B., Gonzalez-Partida E.
Publicada:
1 ene 1984
Resumen:
Two principal types of sulphide occurrences have been recognized in the province: 1) exhalative-like massive sulphide deposits enclosed in the metamorphic Tizapa sequence and 2) quartz veins with sulphide concentrations spatially related to intrusive monzogranite stocks. The characteristics of the hydrothermal mineralizing solutions were determined, using fluid inclusion studies. Three different types of solutions were identified: 1) hypersaline brines close to halite saturation at approx 500oC with boiling point approx 420oC. These are related to the volcanism associated with the massive sulphide occurrences; 2) complex carbonic solutions related to the epizonal metamorphism of the Tizapa sequence; and 3) aqueous solutions associated with ore veins of salinity decreasing with homogenization T from 10 to 1 equiv. wt.% NaCl and 350o-150oC. The K/Na ratio is high, approx 0.3. There is no evidence for boiling. The geothermal gradient is estimated at approx 80oC/km. The genetic model postulated from S isotope data supports a selective remobilization of the massive or disseminated sulphides originally trapped in the Tizapa sequence by circulation of meteoric water within the granitic intrusions.-P.Br.
Filiaciones:
Charoy B.:
Ecole Nationale Superieure de Geologie Appliquee, B.P. 452, 54001 Nancy Cedex, France., France
Gonzalez-Partida E.:
Ecole Nationale Superieure de Geologie Appliquee, B.P. 452, 54001 Nancy Cedex, France., France
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