Geochemistry and 207Pb/206Pb zircon ages of granitoids from the southern portion of the Tamboril–Santa Quitéria granitic–migmatitic complex, Ceará Central Domain, Borborema Province (NE Brazil)

Autor: Candido Augusto Veloso Moura, Felipe Grandjean da Costa, Tercyo Rinaldo Gonçalves Pinéo, Carlos Eduardo Ganade de Araujo, José C. Cavalcante
Rok vydání: 2012
Předmět:
Zdroj: Journal of South American Earth Sciences. 33:21-33
ISSN: 0895-9811
DOI: 10.1016/j.jsames.2011.07.009
Popis: The Tamboril–Santa Quiteria Complex is an important Neoproterozoic granitic–migmatitic unit from the Ceara Central Domain that developed from ca. 650 to 610 Ma. In general the granitoids range in composition from diorite to granite with predominance (up to 85%) of granitic to monzogranitic composition with biotite as the main mafic AFM phase. Geochemical and 207Pb/206Pb evaporation zircon geochronology studies were applied in a group of these abundant monzogranitic rocks from the region of Novo Oriente in the southern portion of the Ceara Central Domain. In this area the granitoids are weakly peraluminous biotite granitoids and deformed biotite granitoids of high-K calc-alkaline and ferroan composition, which we interpreted as primary magmas (segregated diatexites) derived from the partial melting of crustal material. The close temporal relation of this magmatism with local eclogitic and regional high temperature metamorphism in Ceara Central Domain point out to an orogenic setting, arguably emplaced during the collisional stage. Subordinate coeval juvenile mantle incursions are also present. This crustally derived magmatism is the primary product of the continental thickening that resulted from the collision between the rocks represented by the Amazonian-West African craton (Sao Luiz cratonic fragment) to the northwest and the Paleoproterozoic–Archean basement of the Borborema Province to the southeast along the Transbrasiliano tectonic corridor.
Databáze: OpenAIRE
Externí odkaz: