Resumen

BUSTAMANTE, Andres et al. CHLORITOID-MUSCOVITE SCHISTS AT EL RETIRO REGION, ANTIOQUIA: GEOTHERMOMETRY AND TECTONIC SIGNIFICANCE. Bol. cienc. tierra [online]. 2013, n.33, pp.5-16. ISSN 0120-3630.

The muscovite-chloritoid schists represent low-grade metamorphism in greenschist-facies of pelitic sediments intercalated with Triassic high grade metamorphic rocks within the Central Cordillera of the Northern Andes. In this paper, we analyzed detailed petrographic and mineral chemistry data, with the aim of applying the chloritoid-chlorite geothermometer and understand the metamorphic evolution and geotectonic implications of this rocks. Through the application of this geothermometer were obtained temperatures varying between 520 and 600 °C showing that this association is stable in low-grade metamorphic and may be transitional to the amphibolite facies in its lower temperature portion. The new field and petrologic observations suggest that these lower grade schists were placed as represent shear zones that affected the metabasites and migmatites of high amphibolite facies. When integrated with published data the results of this study confirmed the existence of a very fast exhumation trend of these Triassic belt which show affinity with conditions of extensional settings. Future research must considered this extensional pattern to evaluate the existence of collisional or subduction related orogens in the Northern Andes.

Palabras clave : chloritoid-chlorite geothermometer; metabasites and migmatites; high amphibolite facies; El Retiro; Northern Andes.

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