info:eu-repo/semantics/article
THE SÃO VICENTE-CAICÓ MASSIF, NORTHEAST BRAZIL: EXAMPLE OF AN EARLY PROTEROZOIC GNEISSIC-MIGMATITIC SUITE WITH FEATURES OF MODERN CALC-ALKALINE I (CORDILLERAN)-TYPE MAGMATISM
THE SÃO VICENTE-CAICÓ MASSIF, NORTHEAST BRAZIL: EXAMPLE OF AN EARLY PROTEROZOIC GNEISSIC-MIGMATITIC SUITE WITH FEATURES OF MODERN CALC-ALKALINE I (CORDILLERAN)-TYPE MAGMATISM
Autor
PETTA, REINALDO ANTONIO
WERNICK, EBERHARD
VERKAEREN, JEAN
DANTAS, ELTON LUIZ
Institución
Resumen
Geological, petrographic, mineralogical, geochemical and isotopic data from the Early Proterozoic gneiss/migmatitic São Vicente-Caicó Massif in the Seridó Area of the Borborema Province, State of Rio Grande do Norte, north-eastern Brazil, are presented and discussed. The Sao Vicente-Caicó Suite includes polymetamorphic and polydeformed rocks of gabbroic to granitic compositions belonging dominantly to the amphibolite facies. It is concluded that the pre-metamorphic rocks are represented by a upper mantle/Archaean lower crust-derived magmatic suite quite similar to Mesozoic/Tertiary normal- to high-K calc-alkaline I (Cordilleran)-type suites which evolved by MASH and ACF processes. Dados geológicos, petrográficos, mineralógicos, geoquímicos e isotópicos do Maciço gnáissico/migmatítico paleoproterozóico São Vicente-Caicó, região do Seridó, Província Borborema, Estado do Rio Grande do Norte, NE do Brasil, são apresentados e discutidos. A Suite São Vicente-Caicó inclui rochas grabróicas e granitóides polimetamórficas e polideformadas dominantemente do fácies anfibolito. Os autores concluem the as rochas pre-metamórficas são representadas por uma associação magmática derivada do manto superior/crosta inferior muito semelhantes as suites Mesozóico/Terciárias calcio-alcalinas do tipo I (Cordilherano), normal a alto-K que evoluiram por processos de MASH e ACF.