Resumo

RIOS-R., Carlos A.; MANTILLA-F., Luis Carlos  e  CASTELLANOS-A., Oscar M.. Petrogenesis of quartz-kyanite veins in metapelitic rocks of the Silgará Formation, central Santander Massif (Colombian Andes). Rev. acad. colomb. cienc. exact. fis. nat. [online]. 2017, vol.41, n.159, pp.230-243. ISSN 0370-3908.  https://doi.org/10.18257/raccefyn.385.

The metamorphic rock of the Silgará formation (sensu lato), of pre-Devonian age, cropping out at the central region of the Santander massif (Colombian Eastern Cordillera), presents slightly boudinated hydrothermal quartz and kyanite veins parallel to the regional metamorphic foliation. These veins are considered as exceptional manifestations due to their restricted distribution in the context of the Santander Massif and their composition and genesis. Kyanite crystals are observed, 1) in the proximity to the contact with the wall metapelitic rocks (affected by amphibolite facies metamorphism, staurolite-kyanite zone), showing a direction parallel to the metamorphic foliation, which indicates a progressive growth during the opening of the vein, and 2) toward the center of the vein, exhibiting random orientation, which suggests a growth control without significant efforts. Based on lithological relationships and paragenetic studies, it is possible to suggest that the formation of these hydrothermal veins is related to the circulation or scape of hydrothermal fluids typical of magmatic-hydrotermal events of Ordovician? age. © 2017. Acad. Colomb. Cienc. Ex. Fis. Nat.

Palavras-chave : Colombia; Santander massif; Silgará formation; Hydrothermal veins; Kyanite.

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