Ordovician A-type granitoid magmatism on the Ceara Central Domain, Borborema Province, NE-Brazil

Autor(es)

Castro, Neivaldo A. ^[1] ; Ganade de Araujo, Carlos E. ^{[2, 3]} ; Basei, Miguel A. S. ^[2] ; Osako, Liliane S. ^[1] ; Nutman, Alan A. ^[4] ; Liu, Dunyi ^[4]

Afiliação do(s) autor(es)

^[1] Univ Fed Ceara, Dep Geol, BR-60115080 Fortaleza, Ceara - Brazil

^[2] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil

^[3] CPRM Geol Survey Brazil, BR-60135101 Fortaleza, Ceara - Brazil

^[4] Beijing SHRIMP Ctr, Beijing 1000037 - Peoples R China

• Tipo de documento: Artigo Científico
• Fonte: Journal of South American Earth Sciences; v. 36, p. 18-31, JUL 2012.
• Citações Web of Science: 19

Resumo

We present field relationships, major and trace element geochemistry and U-Pb SHRIMP and ID-TIMS geochronology of the A-type Ordovician Quintas pluton located in the Ceara Central Domain of the Borborema Province, in northeastern Brazil. This pluton presents a concentric geometry and is composed mainly of syenogranite, monzogranite, quartz syenite to quartz monzodiorite, monzogabbro and diorite. Its geochemical characteristics {[}SiO2 (52-70%), Na2O/K2O (1.55-0.65), Fe2O3/MgO (2.2-7.3), metaluminous to sligthly alkaline affinity, post-collisional type in (Y + Nb) x Rb diagram, and A-type affinity (Ga > 22 ppm, Nb > 20 ppm, Zn > 60 ppm), REE fractioned pattern with negative Eu anomaly] are coherent with post-collisional A(2)-type granitoids. However, the emplacement of this pluton is to some extent temporally associated with the deposition of the first strata of the Parnaiba intracratonic basin, attesting also to a purely anorogenic character (A(1)-type granitoid). The emplacement of this pluton is preceded by one of the largest known orogenesis of the planet (Neoproterozoic Pan-African/Brasiliano) and, if it is classified as an A(2)-type granitoid, it provides interesting constraints about how long can last A(2)-type magmatic activity after a major collisional episode, arguably triggered by disturbance of the underlying mantle, a topic extensively debated in the geoscience community. (C) 2011 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 05/58688-1 - A América do Sul no contexto dos supercontinentes: fusão e fissão
• Beneficiário: Miguel Angelo Stipp Basei
• Modalidade de apoio: Auxílio à Pesquisa - Temático