Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/3526
Título: | U–Pb zircon and monazite geochronology of post-collisional hercynian granitoids from the Central Iberian Zone (Northern Portugal) |
Autor(es): | Dias, G. Leterrier, J. Mendes, Anabela Carreira Simões, P. P. Bertrand, J. M. |
Palavras-chave: | Iberian Peninsula Hercynian Granitoids Zircon Monazite U–Pb geochronology |
Data: | Dez-1998 |
Editora: | Elsevier 1 |
Revista: | Lithos |
Citação: | Dias, G., Leterrier, J., Mendes, A., Simões, P. P., & Bertrand, J. M. (1998). U–Pb zircon and monazite geochronology of post-collisional Hercynian granitoids from the Central Iberian Zone (Northern Portugal). Lithos, 45(1), 349-369. doi: https://doi.org/10.1016/S0024-4937(98)00039-5 |
Resumo(s): | In the Central Iberian Zone (CIZ) of the Iberian Massif large volumes of granitoids were emplaced during the post-collisional stage of the Hercynian orogeny (syn- to post-D3, the last ductile deformation phase). Twelve granitic units and a quartz monzodiorite were selected for a U–Pb zircon and monazite geochronological study. They represent successive stages of the D3 event. The Ucanha-Vilar, Lamego, Sameiro and Refoios do Lima plutons are coeval (313±2 Ma, 319±4 Ma, 316±2 Ma and 314±2 Ma, respectively) and belong to the earliest stage. Later on the Braga massif was emplaced, its different units yielding the same age: 309±3 Ma for the Braga granite, 309±1 Ma for the Gonça granite and 311±5 Ma for a related quartz monzodiorite. The Braga massif is subcontemporaneous with the Agrela and Celeirós plutons (307±3.5 Ma and 306±2 Ma, respectively), in agreement with field data. The Briteiros granite is younger (300±1 Ma), followed by the emplacement of the Peneda–Gerês massif (Gerês, Paufito, Illa and Carris granites). The Gerês granite, emplaced at 296±2 Ma, seems to represent a first magmatic pulse immediately followed by the intrusion of the Paufito granite at 290±2.5 Ma. For the Carris granite a minimum emplacement age of 280±5 Ma was obtained. Based on these results the following chronology is proposed: (1) syn-D3 biotite granitoids, 313–319 Ma; (2) late-D3 biotite-dominant granitoids, 306–311 Ma; (3) late- to post-D3 granitoids, ca. 300 Ma; (4) post-D3 granitoids, 290–296 Ma. These chronological data indicate that successive granitic intrusions were emplaced in the CIZ during a short time span of about 30 Ma that corresponds to the latest stages of the Hercynian orogeny. A rapid and drastic change occurred at about 300 Ma, between a compressive ductile tectonic regime (D3, ca. 300–320 Ma) associated to calc-alkaline, monzonitic and aluminopotassic plutonism and a fragile phase of deformation (D4) which controlled the emplacement of the subalkaline ferro-potassic plutonism at 290–296 Ma. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/3526 |
DOI: | 10.1016/S0024-4937(98)00039-5 |
ISSN: | 0024-4937 |
Versão da editora: | http://www.sciencedirect.com/science/article/pii/S0024493798000395 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CCT - Artigos (Papers)/Papers |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
---|---|---|---|---|
Lithos,1998.pdf | Documento principal | 732,97 kB | Adobe PDF | Ver/Abrir |