Ocurrencia, composición química y significado genético de la biotita en las rocas metamórficas de la Formación Silgará en la región suroccidental del Macizo de Santander
No Thumbnail Available
Date
Authors
Advisors
Evaluators
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad Industrial de Santander
Abstract
Description
La Formación Silgará del Paleozoico Inferior es una secuencia principalmente compuesta por rocas metapelíticas e intercalaciones de rocas máficas que forma parte del basamento metamórfico que aflora en la región suroccidental del Macizo de Santander. Las rocas metamórficas de la Formación Silgará han sido afectadas por un metamorfismo de tipo Barroviense, desarrollándose una secuencia de zonas metamórficas (silimanita, estaurolita-cianita, granate, y biotita). El metamorfismo ha ocurrido bajo condiciones de temperatura alta y presión media, alcanzando la facies de anfibolita. Durante el proceso de metamorfismo prógrado de las rocas metamórficas del Macizo de Santander, la biotita ha crecido en un rango amplio de condiciones de presión y temperatura, y el cambio en su composición química tiende a reflejar el efecto de la química de la roca original antes que el grado de metamorfismo.
The Lower Paleozoic Silgará Formation is a sequence compossed mainly by metapelitic rocks and interlayered mafic rocks that form part of the metamorphic basement that crops out in the southwestern region of the Santander Massif. The Silgará Formation of metamorphic rocks have been affected by a Barrovian type metamorphism, developing a sequence of metamorphic zones (sillimanite, staurolite-kyanite, garnet, and biotite). Metamorphism has occurred under high-temperature and medium-pressure conditions, reaching the amphibolite facies. During the prograde metamorphism of the Santander Massif metamorphic rocks, the biotite has grown in a wide range of pressure and temperature conditions, and the change in its chemical composition tends to reflect the effect of the bulk-rock chemistry rather than the grade of metamorphism.
The Lower Paleozoic Silgará Formation is a sequence compossed mainly by metapelitic rocks and interlayered mafic rocks that form part of the metamorphic basement that crops out in the southwestern region of the Santander Massif. The Silgará Formation of metamorphic rocks have been affected by a Barrovian type metamorphism, developing a sequence of metamorphic zones (sillimanite, staurolite-kyanite, garnet, and biotite). Metamorphism has occurred under high-temperature and medium-pressure conditions, reaching the amphibolite facies. During the prograde metamorphism of the Santander Massif metamorphic rocks, the biotite has grown in a wide range of pressure and temperature conditions, and the change in its chemical composition tends to reflect the effect of the bulk-rock chemistry rather than the grade of metamorphism.
Keywords
Santander Massif, Barrovian, biotite, Macizo de Santander, Barroviense, biotita