Petrografia, geoquímica e geocronologia dos granitos patrimônio Santo Antônio e São Domingos (Suíte Cunhaporanga, Paraná, Sudeste do Brasil)

The Patrimônio Santo Antônio and São Domingos Granites are located in the northwest portion of the Itaiacoca Belt, which is part of the Apiaí Terrane (or tectonic domain), a segment of the southern Ribeira Belt, the major tectonic unit of the Mantiqueira Province (Southeast Brazil). These granites are related to the Cunhaporanga Granitic Suite and are intrusive into metasedimentary rocks of the Itaiacoca Group. The plutons are represented mainly by porphyritic monzogranites, with rare occurrences of syenogranites. The porphyritic monzogranites are ferroan to magnesian, high-K, alkali-calcic, and metaluminous to peraluminous. Trace elements patterns of the granites, which have been locally affected by hydrothermal alteration, suggest an association with magmas emplaced in a late- to post-tectonic setting. The geochemical signatures suggest a mantle source enriched in incompatible elements remobilized from the oceanic crust during subduction. The geochronological age of the Patrimônio Santo Antônio Granite (589 ± 6 Ma, zircon, U-Pb SHRIMP) indicates that the magmatism associated with these plutons occurred between the final stages of evolution of the Cunhaporanga Granitic Suite (ca. 650 to 590 Ma) and the emplacement of the post-orogenic and anorogenic plutons of the Apiaí Domain (ca. 590 to 570 Ma).Os Granitos Patrimônio Santo Antônio e São Domingos localizam-se na porção noroeste da Faixa Itaiacoca constituinte do Terreno (ou domínio tectônico) Apiaí segmento do Cinturão Ribeira Meridional da Província Mantiqueira localizada no sudoeste do Brasil. Ambos estão relacionados com a Suíte Granítica Cunhaporanga e são intrusivos em rochas metassedimentares do Grupo Itaiacoca. São constituídos por ocorrências esparsas de sienogranitos e majoritariamente por monzogranitos porfiríticos de caráter metaluminoso a peraluminoso, álcali-cálcico de alto K e comportamento ferroso a magnesiano. O comportamento dos elementos traços, por vezes afetado por alteração hidrotermal, é sugestivo de magmatismo pós a tardi-colisional, com assinaturas geoquímicas que sugerem origem a partir de manto enriquecido pela adição de elementos incompatíveis remobilizados de crosta oceânica durante subducção. A idade geocronológica obtida para o Granito Patrimônio Santo Antônio (589 ± 6 Ma, zircões, U-Pb, SHRIMP) situa o magmatismo destes plútons entre os estágios finais de evolução da Suíte Granítica Cunhaporanga (ca. 650 a 590 Ma) e da colocação dos plútons pós-orogênicos e anorogênicos do Domínio Apiaí (ca. 590 a 570 Ma)

Petrography, Geochemistry and Geochronology of the Patrimônio Santo Antônio and São Domingos Granites (Cunhaporanga Granitic Suite, Paraná, Southeast Brazil)

The Patrimônio Santo Antônio and São Domingos Granites are located in the northwest portion of the Itaiacoca Belt,which is part of the Apiaí Terrane (or tectonic domain), a segment of the southern Ribeira Belt, the major tectonic unit of theMantiqueira Province (Southeast Brazil). These granites are related to the Cunhaporanga Granitic Suite and are intrusive intometasedimentary rocks of the Itaiacoca Group. The plutons are represented mainly by porphyritic monzogranites, with rareoccurrences of syenogranites. The porphyritic monzogranites are ferroan to magnesian, high-K, alkali-calcic, and metaluminousto peraluminous. Trace elements patterns of the granites, which have been locally affected by hydrothermal alteration, suggestan association with magmas emplaced in a late- to post-tectonic setting. The geochemical signatures suggest a mantle sourceenriched in incompatible elements remobilized from the oceanic crust during subduction. The geochronological age of thePatrimônio Santo Antônio Granite (589 ± 6 Ma, zircon, U-Pb SHRIMP) indicates that the magmatism associated with theseplutons occurred between the fi nal stages of evolution of the Cunhaporanga Granitic Suite (ca. 650 to 590 Ma) and theemplacement of the post-orogenic and anorogenic plutons of the Apiaí Domain (ca. 590 to 570 Ma)