| Full text | |
| Author(s): |
Castro, Neivaldo A.
[1]
;
Ganade de Araujo, Carlos E.
[2, 3]
;
Basei, Miguel A. S.
[3]
;
Osako, Liliane S.
[1]
;
Nutman, Alan A.
[4]
;
Liu, Dunyi
[4]
Total Authors: 6
|
| Affiliation: | [1] Univ Fed Ceara, Dep Geol, BR-60115080 Fortaleza, Ceara - Brazil
[2] CPRM Geol Survey Brazil, BR-60135101 Fortaleza, Ceara - Brazil
[3] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil
[4] Beijing SHRIMP Ctr, Beijing 1000037 - Peoples R China
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | Journal of South American Earth Sciences; v. 36, p. 18-31, JUL 2012. |
| Web of Science Citations: | 19 |
| 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 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) | |
| FAPESP's process: | 05/58688-1 - South America in the context of supercontinents: fusion and fission |
| Grantee: | Miguel Angelo Stipp Basei |
| Support type: | Research Projects - Thematic Grants |