Characterization of volcanic structures associated to the silicic magmatism of the Paraná-Etendeka Province, in the Aparados da Serra region, southern Brazil
Título del documento: Characterization of volcanic structures associated to the silicic magmatism of the Paraná-Etendeka Province, in the Aparados da Serra region, southern Brazil
Revista: Anais da Academia Brasileira de Ciencias
Base de datos: PERIÓDICA
Número de sistema: 000436110
ISSN: 0001-3765
Autores: 1
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Instituciones: 1Universidade Federal do Rio Grande do Sul, Instituto de Geociências, Porto Alegre, Rio Grande do Sul. Brasil
Año:
Volumen: 92
Número: 2
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Analítico, descriptivo
Resumen en inglés The Paraná-Etendeka Magmatic Province is associated with the distensive tectonics that caused the rupture of the Gondwana continent during the Lower Cretaceous and generated an intense volcanism that covers South America and the NW portion of Namibia in Africa. In Brazil, this volcanic sequence is named Serra Geral Group and predominantly consists of basalts and subordinated silicic rocks. The goal of this study is to characterize the geomorphological features observed in the Aparados da Serra region, southern Brazil, and to evaluate the relationship between these structures and the primary silicic volcanic structures. The geomorphological features were first identified using remote sensing and then correlated with flow structures observed in the field, as well as petrographic and geochemical data. AMS data were used to determine magnetic patterns and the direction of magmatic flow of the rocks. Despite the low degree of anisotropy, clear patterns of lineation and foliation were identified in the studied rocks. Our data shows that Units I and II correspond to silicic lava flows linked to effusive fissure eruptions, presenting a dome morphology caused by differential erosion. Unit III rocks may correspond to true volcanic domes, whereas the Unit IV corresponds to the effusive feeder structures
Disciplinas: Geociencias
Palabras clave: Sismología y vulcanología,
Morfología volcánica,
Lavas silícicas,
Anisotropía,
Susceptibilidad magnética
Keyword: Seismology and volcanology,
Anisotropy,
Magnetic susceptibility,
Silicic lavas,
Volcanic morphology
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