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Novos dados U-Pb em zircão do Maciço de Évora e correlação com as unidades basais da Zona de Galiza-Trás-os-Montes
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Abstract(s)
SUMMARY: We present new U-Pb zircon data from the Évora Massif (SW Ossa–Morena Zone). Série Negra paragneiss of Escoural Fm. yields a maximum depositional age of ~580 Ma. Felsic orthogneiss “leptinites” included in Escoural Fm., commonly attributed to the Precambrian, yield a concordant age of 513 ± 3 Ma. Felsic volcanics interbedded in the Monfurado Fm. and the Safira Orthogneiss show very discordant zircon ages and two systematic populations at ~510 Ma and ~460 Ma. Given the stratigraphic constraint of Monfurado Fm., both magmatic rocks are considered coeval and emplaced at ~510 Ma during the main rift-related magmatism. The ~460 Ma age is not fully understood yet. Given the differences in the ages of magmatism in the Évora Massif, recently correlated with the Lower Allochthon of Galiza-Trás-os-Montes Zone, where only late rift-related magmatism is recorded, we suggest that they represent different sedimentary basins positioned in the same paleogeographic contexts.
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Keywords
Ossa-Morena Zone Magmatism Rifting Galiza-Trás-os-Montes Zone Zona de Ossa-Morena Magmatismo Zona de Galiza-Trás-os-Montes
Citation
Solá, A.Rita; Chichorro, Martim; Cachapuz, P.; Santos, Telmo M. Bento dos (2023) - Novos dados U-Pb em zircão do Maciço de Évora e correlação com as unidades basais da Zona de Galiza-Trás-os-Montes. In: Lopes, F. C., Dinis, P. A., Duarte, L. V. e Cunha, P. P. (Coords.). XI Congresso Nacional de Geologia: Geociências e Desafios Globais. Livro de Resumos. Coimbra, 16- 20 julho de 2023, Departamento de Ciências da Terra da Universidade de Coimbra (eds.), p. 39-40. ISBN: 978-989-98914-8-7
Publisher
Departamento de Ciências da Terra da Universidade de Coimbra