Characterization of volcanic structures associated to the silicic magmatism of the Paraná-Etendeka Province, in the Aparados da Serra region, southern Brazil
Document title: Characterization of volcanic structures associated to the silicic magmatism of the Paraná-Etendeka Province, in the Aparados da Serra region, southern Brazil
Journal: Anais da Academia Brasileira de Ciencias
Database: PERIÓDICA
System number: 000436110
ISSN: 0001-3765
Authors: 1
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Institutions: 1Universidade Federal do Rio Grande do Sul, Instituto de Geociências, Porto Alegre, Rio Grande do Sul. Brasil
Year:
Volumen: 92
Number: 2
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Analítico, descriptivo
English abstract 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
Disciplines: Geociencias
Keyword: 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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