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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Strain distribution across a partially molten middle crust: Insights from the AMS mapping of the Carlos Chagas Anatexite, Aracuai belt (East Brazil)

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Author(s):
Cavalcante, Geane C. G. [1, 2, 3] ; Egydio-Silva, Marcos [1] ; Vauchez, Alain [2, 3] ; Camps, Pierre [2, 3] ; Oliveira, Euridice [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil
[2] Univ Montpellier 2, Geosci Montpellier, F-34095 Montpellier 05 - France
[3] CNRS, F-34095 Montpellier 05 - France
Total Affiliations: 3
Document type: Review article
Source: JOURNAL OF STRUCTURAL GEOLOGY; v. 55, p. 79-100, OCT 2013.
Web of Science Citations: 10
Abstract

The easternmost part of the Neoproterozoic Aracuai belt comprises an anatectic domain that involves anatexites (the Carlos Chagas unit), leucogranites and migmatitic granulites that display a well-developed fabric. Microstructural observations support that the deformation occurred in the magmatic to submagmatic state. Structural mapping integrating field and anisotropy of magnetic susceptibility (AMS) revealed a complex, 3D structure. The northern domain displays gently dipping foliations bearing a NW-trending lineation, southward, the lineation trend progressively rotates to EW then SW and the foliation is gently folded. The eastern domain displays E W and NE SW trending foliations with moderate to steeply dips bearing a dominantly NS trending lineation. Magnetic mineralogy investigation suggests biotite as the main carrier of the magnetic susceptibility in the anatexites and ferromagnetic minerals in the granulites. Crystallographic preferred orientation (CPO) measurements using the electron backscatter diffraction (EBSD) technique suggest that the magnetic fabric comes from the crystalline anisotropy of biotite and feldspar grains, especially. The delineation of several structural domains with contrasted flow fabric suggests a 3D flow field involving westward thrusting orthogonal to the belt, northwestward orogen-oblique escape tectonics and NS orogen-parallel flow. This complex deformation pattern may be due to interplay of collision-driven and gravity-driven deformations. (C) 2013 Elsevier Ltd. All rights reserved. (AU)

FAPESP's process: 10/03537-7 - Tectonoseismic Study of the Carlos Chagas Leucogranite and Adjacent Units, Araçuaí Belt (Eastern Brazil).
Grantee:Geane Carolina Gonçalves Cavalcante
Support Opportunities: Scholarships in Brazil - Doctorate