High-pressure granulites from Carire, Borborema Province, NE Brazil: Tectonic setting, metamorphic conditions and U-Pb, Lu-Hf and Sm-Nd geochronology

Autor(es)

Amaral, Wagner da Silva ^{[1, 2]} ; dos Santos, Ticiano Jose Saraiva ^[1] ; Wernick, Eberhard ^[3] ; Nogueira Neto, Jose de Araujo ^[2] ; Dantas, Elton Luiz ^[4] ; Matteini, Massimo ^[4]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Geosci, BR-13081970 Campinas, SP - Brazil

^[2] Univ Fed Ceara, Dept Geol, BR-60455760 Fortaleza, Ceara - Brazil

^[3] Sao Paulo State Univ, Inst Geosci & Exact Sci, BR-13050318 Rio Claro, SP - Brazil

^[4] Univ Brasilia, Inst Geosci, BR-70910900 Brasilia, DF - Brazil

• Tipo de documento: Artigo Científico
• Fonte: GONDWANA RESEARCH; v. 22, n. 3-4, p. 892-909, NOV 2012.
• Citações Web of Science: 25

Resumo

In the northwest region of the Ceara Central Domain, Borborema Province, an elongate area of mylonitic diorites and granodiorites is structurally controlled by NE-SW-trending strike-slip faults. Granitic material and layers and lenses of felsic and mafic granulites occur along the main shear zones. We present and discuss petrographic, geothermobarometric. and geochronological (LA-MC-ICPMS U-Pb and Lu-Hf in zircon and Sm-Nd whole-rock) data for these rocks. Felsic granulites are composed of orthopyroxene + clinopyroxene + plagioclase + quartz +/- hornblende +/- garnet +/- biotite +/- feldspar, while the mafic granulites comprise clinopyroxene + plagioclase + garnet + hornblende +/- rutile +/- quartz. The P-T conditions recorded range from 9.4 to 83 kbars and from 804 to 870 degrees C for the felsic granulites and from 13.6 to 10.2 kbars and 910 to 750 degrees C for the mafic granulites. U-Pb zircon ages of granodiorite host rocks are 2157 and 2044 Ma. The felsic granulites yield a U-Pb age of 2110 Ma, while the mafic granulites yield U-Pb zircon ages of 613 and 589 Ma for the metamorphic recrystallization. Sm-Nd and Lu-Hf T-DM ages for the mafic granulites are similar (1.6-1.3 Ga) and share positive values of epsilon(Nd) and epsilon(Hf), which suggests that these mafic rocks were derived from a juvenile Mesoproterozoic crust. In addition, the felsic granulites and the granodiorites have similar TDM-Nd and U-Pb ages (with positive values of epsilon(Nd)), indicating a Paleoproterozoic mantle source for these rocks. (C) 2012 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 03/07663-3 - Evolução tectônica do arco magmático de Santa Quitéria, NW da Província Borborema
• Beneficiário: Ticiano José Saraiva dos Santos
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 07/58535-6 - Rochas metabásicas da região entre o arco magmático de Santa Quiteria e o lineamento transbrasiliano: importância de suturas colisionais no Domínio Ceará Central - noroeste da Província Borborema
• Beneficiário: Ticiano José Saraiva dos Santos
• Modalidade de apoio: Auxílio à Pesquisa - Regular