Title of article
Ordovician A-type granitoid magmatism on the Cearل Central Domain, Borborema Province, NE-Brazil
Author/Authors
Castro، نويسنده , , Neivaldo A. and Ganade de Araujo، نويسنده , , Carlos E. and Basei، نويسنده , , Miguel A.S. and Osako، نويسنده , , Liliane S. and Nutman، نويسنده , , Alan A. and Liu، نويسنده , , Dunyi، نويسنده ,
Issue Information
روزنامه با شماره پیاپی سال 2012
Pages
14
From page
18
To page
31
Abstract
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 Ceará 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) × 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 A2-type granitoids. However, the emplacement of this pluton is to some extent temporally associated with the deposition of the first strata of the Parnaíba intracratonic basin, attesting also to a purely anorogenic character (A1-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 A2-type granitoid, it provides interesting constraints about how long can last A2-type magmatic activity after a major collisional episode, arguably triggered by disturbance of the underlying mantle, a topic extensively debated in the geoscience community.
Keywords
A-type granitoid , Borborema Province , Cearل Central Domain , Post-collisional , Anorogenic
Journal title
Journal of South American Earth Sciences
Serial Year
2012
Journal title
Journal of South American Earth Sciences
Record number
2240158
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