Li-rich pegmatites and related peraluminous granites of the Fregeneda-Almendra field (Spain-Portugal): A case study of magmatic signature for Li enrichment

• Tipo: Artigo em Revista Científica Internacional
• Data: 2023

Autores

Roda-Robles, E (Autor) Outra; Vieira, R (Autor) Outra; Alexandre Lima (Autor) FCUP; Errandonea-Martin, J (Autor) Outra; Pesquera, A (Autor) Outra; Cardoso-Fernandes, J (Autor) FCUP; Garate-Olave, I (Autor) Outra

Revista

Título: Lithos

Vol. 452

ISSN: 0024-4937

Editora: Elsevier

Indexação

ISI Web of Knowledge - 15 Citações

Scopus - 16 Citações

Outras Informações

ID Authenticus: P-00Y-B9Q

DOI: 10.1016/j.lithos.2023.107195

Abstract (EN): Based on field and petrographic observations, mineralogical, geochemical (whole-rock by ICP-MS, ICP-OES, ISE and PGNAA) and geochronological (Ar-Ar on mica and U-Pb on columbite) data, ten pegmatite types and one type of cassiterite-rich quartz hydrothermal veins have been distinguished in the Fregeneda-Almendra field (FA) (Central Iberian Zone), some of them highly enriched in Li (included in petalite, spodumene and Li-rich mica). The pegmatites and the veins mostly intrude Neoproterozoic to Cambrian rocks from the Schist-Greywacke Complex. Felsic igneous magmatism during syn- to late-D3 stages (approximate to 320-295 Ma) of the Variscan orogeny was important and nearly continuous in the area, with the overlap of different granitic units of highly peraluminous S-type composition. The most important in outcrop corresponds to the Meda-Escalha similar to o-PenedonoLumbrales granitic complex (MEPL), which belongs to a two-mica leucogranitic series. The other granitic units (Saucelle, Feli and East-MEPL granites) are younger and belong to a P-rich, Ca-poor monzogranitic series. Spatial relationships, together with chemical, mineralogical and geochronological data, indicate that all the pegmatite types and the cassiterite-rich quartz hydrothermal veins are not cogenetic, being related to three different magmatic events: (i) (approximate to 319-313 Ma) includes the syn-D3 MEPL granite and three types of barren pegmatites (intragranitic, quartz+andalusite layers and simple concordant pegmatites); (ii) (approximate to 305-300 Ma) corresponds to the late to post-D3 Feli granite, related to a group of cassiterite-rich quartz veins; and, (iii) (approximate to 300-298 Ma) represents the late- to post-D3 East-MEPL and Saucelle granites, likely parental of some barren aplitic-pegmatitic apophyses and the discordant intermediate and Li-rich pegmatites. These latter form part of a general granitepegmatite fractionation trend.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 20