Geologia, Petrografia, Geoquimica e Isótopos Sm-Nd e Sr-Sr da unidade Bingem e suas relações com o complexo Rio Negro, na área compreendida entre Xerém e Petrópolis, RJ

• Autor(a) principal: Silva, Victor Gustavo Mund da Rocha e
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/7047
• topic: Geochemistry; Lito-Geochemistry; Petrography; Faixa Ribeira; Rio Negro Complex; Rio Negro Magmatic Arch; Isotope Geochronology; Bingen Unit; Santo Aleixo Unit.; Geoquimica; Lito-geoquímica; Petrografia; Faixa Ribeira; Complexo do Rio Negro; Arco Magmatico do Rio Negro; Geocronologia Isotópica; Unidade Bingen; Unidade Santo Aleixo; CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS

This work consists on the structure and deformational evolution characterization of the orthogneisses and granitoid rocks located in the southern slope of the Serra do Mar between Petrópolis and Xerém (RJ) delimited by the geographic coordinates 22° 30´ e 22° 35´ S e 43° 10´ e 43° 15´ E, focusing on the Bingen Unit, through field research, petrographic, lithogeochemic and isotopic studies. The geological setting of the area consists of orthogneisses and granites, the first ones corresponding to the Bingen and Santo Aleixo Units, both belonging to the Rio Negro Complex, and the last ones integrating many granite generations, ranging from sin-tectonics to late and post orogenic. During the field researches the orthogneisses were mapped, described and sampled, being posteriorly classified through macro and microscopic petrographic analyses in the laboratory. The samples were also prepared and submitted to geochemical and geochronological analyses whose results were treated and compared to the literature data available for the Rio Negro Complex through plotting obtained data in many geochemistry diagrams, including rocks classification, magmatic series, aluminum saturation index, tectonic provenience, rare earth elements distribution etc., as well as model age diagrams, based on the Sm-Nd, Sr-Sr isotope analyses. Sustained on the obtained data, the work concludes that the Santo Aleixo and Bingen Units represents respectively the less and more evolved terms of a magmatic series that belongs to the Rio Negro Complex and the last one, correspond to the last products generated by the arch. Those rocks, during its crustal placement, would ve been contaminated by the overlapping plate, thus justifying its K2O enriched chemistry and it s slightly more radiogenic isotopic component in comparison to the usually observed to the Rio Negro Complex.