Geoquímica e estrutura dos ortognaisses das ilhas do Balneário Barra do Sul e de São Francisco do Sul, litoral norte do Estado de Santa Catarina

The rocks of the islands of Balneario Barra do Sul outcrop in northern coast of Santa Catarina state and are distributed along the N15-20E direction. These rocks comprise the northern Dom Feliciano Belt, located to the east of the Luis Alves Microplate and belong to the San Francisco South Complex (Paranagua Terrane). The research was developed by means ofdetailed cartography, petrography, geochemistry and structural analysis. The Remedios and Feia islands are composed of granodiorite and monzogranitemylonites having gneissic aspect. These rocks underwent two phases of ductile deformation: the first is related to thrusting and the second is related to sinistral strike-slip tectonics. These rocks are arecalc-alkalic and alkali-calcic, and metaluminous to weakly peraluminous. They show characteristics of I-type cordilleran granitewhose origin is attributed to continental magmatic arc.