Zircon crystal morphology and internal structures as a tool for constraining magma sources: Examples from northern Portugal Variscan biotite-rich granite plutons

• Tipo: Artigo em Revista Científica Internacional
• Data: 2014

Autores

Helena Brites B Martins (Autor) FCUP; Pedro P Simoes (Autor) Outra; Joana Abreu (Autor) Outra

Revista

Título: Comptes Rendus - Geoscience

Vol. 346

Páginas: 233-243

ISSN: 1631-0713

Editora: Academie des Sciences

Indexação

ISI Web of Knowledge - 10 Citações

Scopus - 11 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Ciências da terra e ciências do ambiente

Outras Informações

ID Authenticus: P-00A-2VH

DOI: 10.1016/j.crte.2014.07.004

Abstract (EN): In northern Portugal, large volumes of granitoids were emplaced during the last stage (D-3) of the Variscan orogeny and display a wide range of petrological signatures. We studied the morphologies and internal structures of zircons from syn-, late- and post-D-3 granitoids. The sin-D-3 granitoids include the Ucanha-Vilar, Lamego, Felgueiras, Sameiro, and Refoios do Lima plutons, the late- and post-D-3 granitoids are represented by the Vieira do Minho and the Vila Pouca de Aguiar plutons, respectively. Typological investigations after Pupin (1980) along with scanning electron microprobe imaging reveal that the external morphology of zircon changes consistently with a decrease in the crystallization temperature. Zircon populations from the Refoios do Lima and the Vieira do Minho granites show gradual changes in the internal morphologies and their typologic evolution trends are consistent with their mainly crustal origin. The Sameiro, Felgueiras, Lamego and Ucanha-Vilar granites have more complex internal and external morphology and typological evolution trends that cross the domain of the calc-alkaline to the aluminous granites compatible with a mixing process. Finally, the morphological types of the Vila Pouca de Aguiar granites are found both in calc-alkaline and sub-alkaline granites and their typological evolutionary trends follow the calc-alkaline/sub-alkaline trend, suggesting crustal sources with some mantle contribution.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 11