Petrography, Geochemistry and Geochronology of the Patrim nio Santo Ant nio and S o Domingos Granites (Cunhaporanga Granitic Suite, Paraná, Southeast Brazil)

The Patrim nio Santo Ant nio and S o 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 thePatrim nio Santo Ant nio 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).