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Termobarometria da suíte metamórfica várzea do Capivarita (Rs): embasamento do Cinturão Dom Feliciano

2002; Sociedade Brasileira de Geologia; Volume: 32; Issue: 4 Linguagem: Inglês

10.5327/rbg.v32i4.996

2317-4889

Andréia Oliveira Monteiro Da Silva, Carla Cristine Porcher, Luís Fernandes, G. T. R. Droop,

Geochemistry and Geologic Mapping

Thermobarometric and structural geology investigation of rocks belonging to the Suite Metamorfica Varzea do Capivarita (SMVC), unit cropping out along the eastern segment of the Dom Feliciano Belt (RS), have revealed that they were affected by two main metamorphic episodes. With the use of THERMOCALC Program it was possible to demonstrate that the older episode (M 1 ), syntectonic to the flat-lying shear zones with E-W tectonic transport direction was developed under conditions of 740-790°C and pressures between 3-4 kbar, belonging, therefore, to the low P/T baric type metamorphism. The younger metamorphic episode (M 2 ) and associated penetrative deformation of impure marbles were developed under amphibolite facies conditions and abundant fluids. The close spacial association and the perfect structural agreement between the Varzea do Capivarita Metamorphic Suit supracrustals rocks and the calc-alcaline gneissic rocks of the Arroio dos Ratos Complex, as the lower pressures of the M 1 metamorphism suggest that this could be cause by the intrusion warm.