Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/59383
Type: Artigo de periódico
Title: PETROGENESIS OF THE LATE PROTEROZOIC CURACA MAFIC DYKE SWARM, BRAZIL - ASTHENOSPHERIC MAGMATISM ASSOCIATED WITH CONTINENTAL COLLISION
Author: OLIVEIRA, EP
TARNEY, J
Abstract: The late Proterozoic Curaca mafic dyke swarm is one of the more alkaline swarms of the Brazilian Precambrian. Intra-dyke chemical variations are characterised by higher abundances of incompatible elements in dyke margins than in the dyke centres, a feature that may have resulted from flowage differentiation, from progressive evacuation of liquids from zoned magma chambers, or possibly through dynamic melting of an uprising diapir. Inter-dyke chemical differences are best interpreted by different extents of melting of a mantle source with a small modal proportion of garnet. This source was heterogeneous and had the trace element compositions of ocean island basalts with Dupal and non-Dupal characteristics. The emplacement of the Curaca dykes from 650-700 Ma may have been facilitated by the extensional tectonics perpendicular to the collision zone between the Sao Francisco craton and the Pernambuco-Alagoas massif during the evolution of the Sergipano orogen. The energy in the system was insufficient to promote much melting of, or interaction with, the continental lithosphere or overlying crust.
Country: Austria
Editor: Springer-verlag Wien
Rights: fechado
Identifier DOI: 10.1007/BF01171945
Date Issue: 1995
Appears in Collections:Unicamp - Artigos e Outros Documentos

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