Produção Nacional
Geologia e geoquímica de granitóides sintectônicos à Zona de Cisalhamento Transcorrente Dorsal de Canguçu, Encruzilhada do Sul, RS
2001; Sociedade Brasileira de Geologia; Volume: 31; Issue: 2 Linguagem: Inglês
10.5327/rbg.v31i2.928
ISSN2317-4889
AutoresEdinei Koester, Luis Alberto D‘Ávila Fernandes, Enio Soliani Júnior, Lauro Valentim Stoll Nardi, Gustavo Kraemer, Arí Roisenberg,
Tópico(s)Geography and Environmental Studies
ResumoSyntectonic granite intrusions to the Dorsal of Cangucu Transcurrent Shear Zone, a lithospheric fault in the Dom Feliciano Belt, Southern Brazil are described , using field relations, petrography and geochemistry. This magmatism can be divided in two types, the early, represented by the Quiteria metagranite and the late, represented by the Arroio Francisquinho and Cordilheira metagranites. They can be distinguished by mineralogy (biotite granites & two-mica granites respectively), SiO 2 contents (64 to 71 % & 70 to 75 %), geochemical affinity (high-K calc-alkaline & peraluminous), REE patterns (strongly & weakly fractioned) and Sr-Sr isotopic ratios (0.716 & 0.732, 0.740). Neoproterozoic ages and radiogenic isotopic compositions have been obtained by Rb-Sr, U-Pb and Sm-Nd dating for these rocks, show the importance of crustal component in their generation, and establish the timing of shear activity with syntectonic magmatism emplacement, around 630 Ma.
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