Metasomatic effect of Li-bearing aplite-pegmatites on psammitic and pelitic metasediments: Geochemical constraints on critical raw material exploration at the Fregeneda–Almendra Pegmatite Field (Spain and Portugal)

作者：Jon Errandonea-Martin, Idoia Garate-Olave, Encarnación Roda-Robles, Joana Cardoso-Fernandes, Alexandre Lima, Maria dos Anjos Ribeiro, Ana Cláudia Teodoro · 发表于：Ore Geology Reviews · 年份：2022 · DOI：10.1016/j.oregeorev.2022.105155 · 被引用次数：49 · 研究领域：Geological and Geochemical Analysis、Geochemistry and Elemental Analysis、Geochemistry and Geologic Mapping

Fluid-assisted mass transfer and re-equilibration of mineral phases are common consequences of metasomatism associated with igneous intrusions. The addition and/or removal of chemical components in these environments may result in the generation of metasomatic aureoles, which can be recognized by their mineralogy and geochemistry. Due to an increasing demand for critical raw materials used in green energy technologies, rare-element granitic pegmatites have seen renewed interest in the mineral exploration industry. Granitic pegmatites represent potential sources of critical commodities and geochemical studies of their related aureoles help to advance techniques in exploration targeting. Moreover, the role and timing of fluid exsolution during magmatic–hydrothermal evolution in granitic–pegmatitic systems and concomitant element mobility remain highly debated. We present a prospect-scale systematic study of geochemical haloes generated by LCT (Li-Cs-Ta) family pegmatite dykes from the Fregeneda–Almendra Pegmatite Field, in the Central Iberian Zone of the Iberian Massif (Spain and Portugal). To understand the magnitude of metasomatic processes linked to these intrusions, we performed whole-rock mass-balance calculation of element gains and losses in variably metasomatized psammitic and pelitic host metasediments. The results show that F, B, Li, Rb, Cs, Sn, Be, Tl, As, W and S (±Mo, Ta) were carried by early exsolved and expelled aqueous fluids. The first evidence of element enri...