(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)
Timing of the HT/LP transpression in the Neoproterozoic Serido Belt (Borborema Province, Brazil): Constraints from U-Pb (SHRIMP) geochronology and implications for the connections between NE Brazil and West Africa
Archanjo, Carlos J.
Viegas, Luiz G. F.
Hollanda, Maria Helena B. M.
Souza, Laecio C.
Número total de Autores: 5
Afiliação do(s) autor(es):
 Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil
 CCET UFRN, Dept Geol, BR-59000900 Natal, RN - Brazil
 Chinese Acad Geol Sci, Beijing SHRIMP Ctr, Beijing 10037 - Peoples R China
Número total de Afiliações: 3
Tipo de documento:
n. 2, SI,
Citações Web of Science:
The Serido schist belt is a classical domain of the Borborema Province (NE Brazil) recording crustal melting at HT/LP conditions in a tectonic setting dominated by dextral transpressive deformation. A comparable tectonometamorphic setting has been described in the Pan-African Igarra and Ilesha schist belts of south Nigeria (Africa). The HT-transpression of the Serido has previously been imprecisely dated by using a range of isotopic methods on a suite of syntectonic granites. We provide new U-Pb zircon ages of the Acari granite and Santa Luzia migmatite that constrain the HT/LP metamorphism of the Serido at c. 575 Ma. Anisotropy of magnetic susceptibility of the Santa Luzia migmatite shows that the magnetic fabric records the NE-trending dextral kinematics similar to those previously described in the Acari pluton. On the other hand, the U-Pb ages of the Totoro pluton provide evidence for an older, mostly mafic to intermediate magmatism intruding the pelitic schist that precedes the HT/LP metamorphism by approximately 15 m.y. In contrast with the Acari pluton and Santa Luzia migmatite, the magnetic fabrics of Totoro show a concentric steep-dipping structure apparently related to magma ascent. Thermobarometric studies in the Serido, Igarra and Ilesha schist belts indicate that a large domain in the northern Borborema and south of the Nigeria shields was deformed at a high temperature and at relatively shallow depths. Although the tectonic setting for such a post-collision HT event remains an open issue, it allows us nevertheless to refine the across-Atlantic geological correlation between the continents. (C) 2012 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. (AU)