Evidence of multiple sources involved in the genesis of the neoproterozoic itapetim granitic complex, NE Brazil, based on geochemical and isotopic data

摘要: Abstract The Itapetim Complex is a multiple facies intrusion of porphyritic monzogranite hosting isolated, or swarms of, dioritic enclaves and cut by late dikes biotite granodiorite. It syn-tectonic in relation to the D3 regional deformation phase Brasiliano Orogeny. complex has contacts with metagreywackes gneissic granites associated Mesoproterozoic Cariris Velhos event and, northwest, belt gneisses Paleoproterozoic ages. At least two different sources seem be involved evolution Complex. diorite source appears depleted mantle that underwent some small degree mixture enriched mafic crust. probably metagreywacke, crust age volcanic rocks related event. granodiorites were generated partial melting compositionally similar those suggested for monzogranite. U–Pb zircon gave crystallization 638±4.9 Ma monzogranites rocks. granodiorite represent magmatic event, under intermediate f O 2 conditions. dikes, intruded into brittle fractures, are 570 Ma intrusions within Pajeu Paraiba Terrane.