%0 Journal Article
%T Caracteriza  o Geoqu¨ªmica de Rochas Metam¨¢ficas e Metaultram¨¢ficas da FaixaPaje¨²-Para¨ªba, Prov¨ªncia Borborema ¨C NE Brasil.
%A C¨ªcera Neysi de Almeida
%A Ignez de Pinho Guimar£¿es
%A Hartmut Beurlen
%A Werner Topitsch
%J Anu¨¢rio do Instituto de Geoci¨ºncias
%D 2009
%I Universidade Federal do Rio de Janeiro
%X Concordant lenses of high pressure metaultramafic and metamafic rocks are positioned in Paleoproterozoic migmatites and orthogneisses of the Paje¨²-Para¨ªba belt, Borborema Province, northeast Brazil. The geochemical signature of theses eclogites facies rocks points to a tholeiitic basaltic composition related to an island arc evolution. They are probably associated with a enriched mantle source underlying a subduction zone. This mantelic source was melted and further underwent in-situ differentiation, producing as high-MgO as high-FeO-TiO2 rocks. Cumulatic pyroxenites could be residual product of this process. The high-FeO-TiO2 group seems to represent more differentiated member submits to crustal contamination event.Reported positive and negative gravimetric anomalies in these metaultramafic and metamafic rocks occurrence area suggest the presence of possible NE-SW to E-W continental collision zone in the Borborema Province.
%K retroeclogites
%K island arc
%K suture zone
%K Borborema Province
%U http://www.anuario.igeo.ufrj.br/2009_1/2009_1_46_61.pdf