Flow-by-flow chemical stratigraphy and evolution of thirteen Serra Geral Group basalt flows from Vista Alegre, southernmost Brazil
The geochemical characterization of thirteen Serra Geral Group flows in the Vista Alegre region (RS-SC), southern Brazil, displays the homogeneous basaltic composition near 50 wt.% SiO2. Each of the five basal flows (Pitanga-type, high-Ti/Y ~600, TiO2 > 3 wt.%) and eight upper flows (Paranapanema-type, medium Ti/Y ~400, TiO2 > 2 wt.%) can be identified from their chemical composition; sets of flows have parallel variation in chemical composition. The flow-by-flowcorrelation in four sections shows the horizontal position of the flows in three profiles and an approximately 200-m downdrop of the Itapiranga block with respect to the Frederico Westphalen block. The world-class amethyst geode mineralization and the systematic presence of native copper in the basalts make the correlation of great geological and economic significance.
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Format: | Digital revista |
Language: | English |
Published: |
Academia Brasileira de Ciências
2011
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Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000200006 |
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