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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.)

Short-lived polyphase deformation during crustal thickening and exhumation of a collisional orogen (Ribeira Belt, Brazil)

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Author(s):
Faleiros, F. M. ; Campanha, G. A. C. ; Pavan, M. ; Almeida, V. V. ; Rodrigues, S. W. O. ; Araujo, B. P.
Total Authors: 6
Document type: Journal article
Source: JOURNAL OF STRUCTURAL GEOLOGY; v. 93, p. 106-130, DEC 2016.
Web of Science Citations: 7
Abstract

The Ribeira Belt (Brazil) is a Neoproterozoic collisional-related feature that was located in a south-central position in West Gondwana. We present quantitative data on finite strain, flow vorticity and deformation temperatures for the Curitiba Terrane, a major segment of the southern Ribeira Belt. Six deformation phases (D-1-D-6) related with crustal thickening and exhumation were recognized. D-1 and D-2-related microstructures are preserved exclusively within porphyroblasts, in part grown during stages of high-pressure (similar to 9-12 kbar) isobaric heating after crustal thickening. D3 phase was active from peak metamorphism attained in contrasting crustal levels (810-400 degrees C), to the early stage of exhumation (500-400 degrees C), as indicated by petrological, microstructural and quartz c-axis fabric evidence. Kinematic vorticity results indicate that the SL3 mylonitic fabric resulted from a simple shear-dominated deformation related with westward thrusting. North-verging overturned D-4 folds with E-W-trending sub horizontal axes derived from a pure shear-dominated deformation. Regional 133 open folds with subvertical axes and NNE-SSW-trending traces were produced by indentation tectonics. D-6 phase comprises retrograde orogen-parallel transcurrent shear zones related with scape tectonics. Geochronological data indicate that D-3-D-6 phases occurred between 584 and 580 Ma, suggesting a fast exhumation rate of similar to 8 mm/year for the deepest rocks from the southern Ribeira Belt. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

FAPESP's process: 15/04487-7 - Metamorphism and tectonic evolution of the southern Ribeira Belt: relationships between the Embu, Apiaí and Curitiba terranes
Grantee:Frederico Meira Faleiros
Support Opportunities: Regular Research Grants