2020-01-102020-01-102016VIANNA, Sâmia Queiroz. Geoquímica isotópica Sm-Nd das rochas graníticas da Suíte Intrusiva Caxipacoré e Piroclásticas da Formação Igarapé Paboca, porção Oeste do Domínio Erepecuru - Trombetas, Província Amazônia Central, Noroeste do Pará. Orientador: Jean Michel Lafon. 2016. 73 f. Trabalho de Curso (Bacharelado em Geologia) - Faculdade de Geologia, Instituto de Geociências, Universidade Federal do Pará, Belém, 2016. Disponível em: https://bdm.ufpa.br/jspui/handle/prefix/2759. Acesso em:.https://bdm.ufpa.br/jspui/handle/prefix/2759The granitic rocks of the Caxipacoré Suite and the volcanic rocks of the Igarapé Paboca Formation in northwestern Pará are part of the two extensive Orosirian volcano-plutonic rocks associations, the oldest association (2.0 to 1.97 Ga) is formed by rocks of the Igarapé Paboca Formation and the Caxipacoré Suite. The youngest association (1.9 to 1.87 Ga) encompasses the volcanic rocks of the Iricoumé Group and granitoids of the Água Branca and Mapuera Suites. The petrographic description of the Caxipacoré granites allowed distinguish two varieties of granitoids (monzogranites and syenogranites) with variable content of hornblende and biotite. Volcanic rocks were classified as ignimbrites, rich in crystaloclasts of sanidine, plagioclase and quartz. The geochemical data allowed the characterization of the rocks the Caxipacoré Suite and Igarapé Paboca formation as high-K alkaline rocks with peraluminous to metaluminous character and ferroan affinity. LILE-enrichment (e.g. K, Rb, Ba and Sr), in relation to the high field strength elements - HFSE ( e.g. Nb, Ta , Zr , Hf and Y) , plus a strong negative Nb and Ta anomalies. In tectonic environments classification diagrams, granitoids and volcanic rocks show geochemical affinity with calc - alkaline rocks related to subduction zones in a continental magmatic arc environment. Nd-T(DM) model ages between 2.37 and 2.52 Ga, and Sr-T(UR) model ages of 2.14 and 1.68 Ga, and negative ƐNdvalues (-1.48 to -3.6) indicate that parental magmas were derived from melting of a Rhyacian sialic crust with a subordinate Archean component. However a Siderian crustal source for the parental magmas cannot be totally discarded. These new isotopic results do not favor the presence of a well developed Archean continental crust in the basement of this sector of the Central Amazon Province.Acesso AbertoGeocronologia - ParáMagmatismo - ParáIsótoposCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::GEOCRONOLOGIATrabalho de Curso - Graduação - Monografia