Origen de los anfíboles y termometría anfíbol - plagioclasa en las rocas máficas del complejo Suya Taco, Sierra de Comechingones, provincia de Córdoba

TIBALDI, A.H., OTAMENDI, J.E. Y DEMICHELIS, A.H.,

Universidad Nacional de Rio Cuarto

Congreso; 7º Congreso de Mineralogía y Metalogenia; 2004

Asociación Mineralógica Argentina

Some mafic rocks in the Suya Taco complex (Sierra de Comechingones) have an important concentration of amphibole, according to Leake (1997) these minerals have been classified like calcic amphibole. Magnesiohanstingite is the predominant amphibole while edenite and actinolite are in less proportion. In general the chemical variation can be explained for a main component of pargarsite substitution add to small component of tschemark substitution while glaucofana exchange only are observed in rocks with magnesiohanstingite-actinolite assemblage. The equilibrium temperature according to Holland and Blundy, (1994) are 836.87-1023, 802-870 and 702.68-720.19°C for assemblage with the join edenite-plagioclase, magnesiohanstingite-plagioclase and actinolite-plagioclase, respectively. These conditions were obtained for pressures ranging from 4 to 7 Kbars. Moreover, according to P-T conditions and textural relations we will be able to propose a possible process, as such as igneous or metamorphic, for the origin and/or evolution of these amphiboles.