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

U-Pb SHRIMP dating of basement rocks of the Iriri-Xingu domain, Central Amazonian province, Amazonian craton, Brazil

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Author(s):
Marcelo Lacerda Vasquez ; Umberto Giuseppe Cordani ; Kei Sato ; Jaime dos Passos de Oliveira Barbosa ; Maria Telma Lins Faraco ; Victor Câmara Maurer
Total Authors: 6
Document type: Journal article
Source: BRAZILIAN JOURNAL OF GEOLOGY; v. 49, n. 3, p. -, 2019.
Web of Science Citations: 0
Abstract

Abstract The Iriri-Xingu domain, located in the central part of the Amazonian craton, consists of extensive occurrences of Paleoproterozoic volcanic rocks and granites with published ages of ca. 1990 to 1840 Ma, which show a strong crustal contribution for their magmas. Exposures of basement rocks are small and rare. Samples from two areas were dated in this work by U-Pb SHRIMP in zircon. In the northern Maribel area, a high-grade pelitic paragneiss presented an age of 2160 ± 8 Ma and the leucosome of a migmatitic orthogneiss, probably a diatexite, crystallized at 2149 ± 20 Ma. These Rhyacian ages suggest that it is part of the Bacajá domain, related to the Trans-Amazonian cycle. The Morro Grande area occurs in the central part of Iriri-Xingu domain, where a high-grade muscovite gneiss with a protolith of 2120-2180 Ma is dated at 1982 ± 7 Ma, and the leucosome of a migmatitic orthogneiss is crystallized at 1979 ± 8 Ma. These are the first records of high-grade metamorphism at ca. 1980 Ma in the Central Brazil shield and may be related to the generation of this Orosirian felsic magmatism, which is widespread throughout the nearby Ventuari-Tapajós province. (AU)

FAPESP's process: 13/12754-0 - U-Pb and LA-ICP-MS precision geochronology on zircon: a contribution to the knowledge of the tectonic evolution of South America
Grantee:Umberto Giuseppe Cordani
Support type: Regular Research Grants