2019-08-292019-08-292010TEIXEIRA, Mayara Fraeda Barbosa. Geocronologia do granito meruoca e diques associados, província borborema , noroeste do estado do Ceará . Orientador: Cândido Augusto Veloso Moura. 2010. 68 f. Trabalho de Curso (Bacharelado em Geologia) – Faculdade de Geologia, Instituto de Geociências, Universidade Federal do Para, Belém, 2010. Disponível em: http://bdm.ufpa.br/jspui/handle/prefix/1718. Acesso em:.http://bdm.ufpa.br/jspui/handle/prefix/1718The Meruoca Granite is a batholite which occurs near the town of Sobral (NW-Ceará) and is limited by the Café-Ipueiras fault zone. To the west of this pluton a sub-parallel E-W dyke swarm occurs, which is known as the Coreaú Dyke Swarm. Both granite and dykes are intrusive in the rocks of the Médio Coreaú domain, which encompasses a Paleoproterozoic basement consisting mainly of migmatitic gneisses and metasedimentary rocks, in addition to Neoproterozoic metasedimentary and volcanic rocks. This work presents geochronological data obtained by zircon Pb-evaporation method for the Meruoca Granite and the Coreaú Dykes, in order to investigate the contemporaneity between this granite pluton and the dyke swarm. Due to the low Pb content of the zircon crystals, or any other singular aspects that prevent a good Pb ionization, the 207Pb/206Pb ages were obtained in groups of three to four crystals deposited in filament, instead of in a single crystal. This procedure, along with the presence of inherited zircon crystals in samples of both Meruoca Granite and the Coreaú Dykes, made it difficult to obtain the crystallization ages for these rocks. However, one of Meruoca Granite crystal sets yielded the age of 518 ± 34 Ma, which was interpreted as the crystallization age of the pluton. This age is similar to a recent published SHRIMP zircon U-Pb age of 523 ± 9 Ma. The Coreaú Dykes yielded the age of 523 ± 20 Ma, similar to the age of crystallization suggested in the present work for the Meruoca Granite. These results support previous studies which suggested that Meruoca Granite and Coreaú Dykes magmatism was coeval.Acesso AbertoGeocronologiaEvaporação de PbGranitogêneseDomínio médio coreaúCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIATrabalho de Curso - Graduação - Monografia