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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.)

Geology and geochronology of the Betara region in south-southeastern Brazil: Evidence for possible Statherian (1.80-1.75 Ga) and Calymmian (1.50-1.45 Ga) extension events

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Author(s):
Siga, Jr., Oswaldo [1] ; Cury, Leonardo Fadel [1] ; McReath, Ian [1] ; de Almeida Leite Ribeiro, Ligia Maria [1] ; Sato, Kei [1] ; Stipp Basei, Miguel Angelo [1] ; Passarelli, Claudia Regina [1]
Total Authors: 7
Affiliation:
[1] Univ Sao Paulo, Inst Geociencias, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: GONDWANA RESEARCH; v. 19, n. 1, SI, p. 260-274, JAN 2011.
Web of Science Citations: 15
Abstract

The results of geological mapping, chemical analysis and radiometric dating of metabasic rocks of Betara Formation, and mapping and dating of those present in the Betara basement nucleus together with mylonitic granodiorite and syenogranite are reported here. U-Pb analysis of bulk zircon fractions from the metabasic rocks of the basement nucleus yielded a Statherian age of 1790 +/- 22 Ma, while the metabasic rocks from the upper part of the Betara Formation yielded a Calymmian age between 1500 and 1450 Ma. This age is a minimum for the deposition of the Betara Formation. The older metabasic rocks are associated with post-tectonic, possibly anorogenic syenogranite, while the younger ones are gabbro or very porphyritic ankaramite whose REE patterns are consistent with crystallization from an N-MORB parent magma. The observations and data point to the probable events associated with extensional processes of the end of Paleoproterozoic and early Mesoproterozoic. Similar registers of Statherian (1.80-1.75 Ga) and Calymmian (1.50-1.45 Ga) extensional events are recorded in other parts of the South American and African continents. The Neoproterozoic witnessed the formation and junction of the tectonic slices which formed the Apiai domain during the assemblage of western Gondwana. (C) 2010 International Association for Gondwana Research. Published by Elsevier B.V. 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