Las serpentinitas de la sierra Pie de Palo y su mineralización metalífera asociada, provincia. de San Juan, Argentina

CASTRO DE MACHUCA, BRÍGIDA; MEISSL, ESTELA; CONTE-GRAND, ALICIA

San Juan)

Congreso; V Congreso Nacional de Geología Económica; 1995

Asociación Argentina de Geólogos Economistas

Previous works in serpentinites from the western flank of the Pie de Palo range describe the occurrence of nickel and chromiun minerals of eventual economical interest. The aim of this study was to corroborate the existence of such manifestations and to establish their mining potential. The diseminated metalliferous mineralization is scarce and averages 3% of the bulk serpentinites. The mineralization is represented by magnetite -the most abundant mineral- and scarce chromite, chalcopyrite, pyrrhotite, pentlandite, digenite, ilmenite, maghemite (?), niccolite, pyrite, rammelsbergite (?), native gold, graphite, hematite and "limonite". The chemical analyses indicate averages of 2723 ppm Cr, 1336 ppm Ni and 111 ppm Co. The tenors of Cu are very low with an average of 23 ppm. The maximun content of Au is 120 ppb. These values are normal for this type of rocks, without constituting in any case anomalies of interest. The reported data do not allow to encourage perspectives concerning possible ore deposits.