Termobarometria e trajetória p-t de metassedimentos do grupo araxá em goiás

EnglishIn the southeastern region of Goias state (Caldas Novas - Morrinhos - Rochedo region) outcrop psammitic, psamopelitic and pelitic metasediments related to the Araxa Group. In the Caldas Novas region (Caldas Novas Domain), the mineral associations related to the metamorphic peak are typical of the upper greenschist facies/lower amphibolite facies and the calculated metamorphic peak indicates temperatures between 500oC and 570oC and pressures between 7-8 kbar, kyanite zone. The mineral associations related to the metamorphic peak in the region between Marcelândia - Morrinhos - Rochedo (Araxa West Domain) are typical of medium to upper amphibolite facies and the thermobarometric calculations show metamorphic peak at 600oC - 670oC and 9-11 kbar, under conditions of amphibolite facies, kyanite zone. The calculations with the geothermometer Zr-in-Rt, performed for pressures of 10 kbar, indicate a minimum temperature of 527oC and a maximum of 688oC. The P-T path, inferred based on textural and thermobarometric data, is clockwise. The mineral associations observed in congruence with mineral chemistry analyzes and thermobarometric studies suggest a progressive metamorphic zoning from E to W in the Araxa Group in the Caldas Novas - Morrinhos - Rochedo region. However, the thermobarometric data suggest that the sets have different metamorphic histories and that metamorphic zoning is a result of tectonic structuring portuguesNa regiao sudeste do estado de Goias (regiao de Caldas Novas – Marcelândia - Morrinhos – Rochedo) afloram metassedimentos peliticos, psamo-peliticos e psamiticos atribuidos ao Grupo Araxa. Na regiao de Caldas Novas (Dominio Caldas Novas) as associacoes minerais relacionadas ao pico metamorfico sao tipicas da transicao da facies xisto verde superior/anfibolito inferior e o auge metamorfico calculado indica temperaturas entre 500oC a 570oC e pressoes entre 7–8 kbar, no campo de estabilidade da cianita. As associacoes minerais relacionadas ao pico metamorfico na regiao entre Marcelândia- Morrinhos – Rochedo (Dominio Araxa Oeste) sao tipicas da facies anfibolito medio a superior e os calculos termobarometricos mostram pico metamorfico a 600oC670oC e 9-11 kbar, em condicoes de facies anfibolito, zona da cianita. Os calculos com o geotermometro Zr em rutilo, realizados para pressoes de 10 kbar, apontam temperatura minima de 611oC e maxima de 692oC. A trajetoria P-T inferida, com base nos dados texturais e termobarometricos, e horaria. As associacoes minerais observadas e os dados termobarometricos sugerem um zoneamento metamorfico progressivo de E para W no Grupo Araxa na regiao, e sugerem