Geology and mineralogy of Li-mineralization in the Central Iberian Zone (Spain and Portugal)
Lithium (Li) mineralization is common in the Central Iberian Zone and, to a lesser extent, in the Galizia-Trás-Os-Montes Zone of Spain and Portugal, occurring along a c. 500 km-long NNW-SSE striking belt. There are different styles of Li mineralization along this belt; they are mainly associated wit...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:addi.ehu.eus:10810/75541 |
| Acceso en línea: | http://hdl.handle.net/10810/75541 |
| Access Level: | acceso abierto |
| Palabra clave: | lithium pegmatites hydrothermal veins granites Variscan orogeny Central Iberian Zone Spain Portugal |
| Sumario: | Lithium (Li) mineralization is common in the Central Iberian Zone and, to a lesser extent, in the Galizia-Trás-Os-Montes Zone of Spain and Portugal, occurring along a c. 500 km-long NNW-SSE striking belt. There are different styles of Li mineralization along this belt; they are mainly associated with aplite-pegmatite bodies and, to a much lesser extent, with veins of quartz and phosphate. Li-mineralization in the CIZ may be classified into four types: aplite pegmatite dykes occurring in pegmatitic fields, Li-mineralization associated with leucogranitic cupolas, beryl-phosphate pegmatites, and quartz-montebrasite veins. The main Li-minerals of these bodies include Li-mica, spodumene and/or petalite in the pegmatitic fields and leucogranitic cupolas; triphylite-lithiophilite in the beryl-phosphate pegmatites, an amblygonite-montebrasite in the quartz-montebrasite veins. The origin of these different styles of mineralization is considered to be related to differentiation of peraluminous melts, which were generated by partial melting of metasedimentary rocks during the Variscan orogeny. On the basis of paragenesis and chemical composition, the pegmatitic fields and Li mineralization associated with granitic cupolas record the highest fractionation levels, whereas the beryl-phosphate pegmatites and quartz-montebrasite veins show lower degrees of fractionation. There are a number of textural and mineralogical indicators for Li-exploration in the Central Iberian Zone and in the Galizia-Trás-Os-Montes Zone, with the highest economic potential for Li being in the pegmatite fields. |
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