A mineralogical-geomorphological terrain analysis of hotspot volcanic islands - The missing link between carbonatite- and pegmatite Nb-F-Zr-Li-Be-bearing REE deposits and new tools for their exploration (Canary Islands Archipelago, Spain)
Two geoscientific disciplines (mineralogy, geomorphology) which are placed far apart from each other are selected to forge a genetic tie line between carbonatite- and agpaitic pegmatite-hosted REE deposits, likewise far away from each other. The Canary Islands Archipelago, Spain, (=CIA) is known as...
| Main Authors: | , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Amsterdam [u.a.] : Elsevier
2023
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| Subjects: | |
| Online Access: | https://www.repo.uni-hannover.de/handle/123456789/17801 https://doi.org/10.15488/17668 |
| Summary: | Two geoscientific disciplines (mineralogy, geomorphology) which are placed far apart from each other are selected to forge a genetic tie line between carbonatite- and agpaitic pegmatite-hosted REE deposits, likewise far away from each other. The Canary Islands Archipelago, Spain, (=CIA) is known as a hotspot hosting REE among other rare elements (28 Ma to the Recent) in volcanic landforms. This rare metal metallogenic province is connected to a carbonatite-pegmatite REE province in NNW Africa. It is a binary mineralization with one hub covering SW Tenerife and NE La Gomera that is characterized by an alkali-magmatite-related REE system with pegmatitic syenites at depth and another hub covering Central - and NW Fuerteventura where (meta) carbonatites are exposed and form a bridge to the REE-bearing carbonatites and pegmatites on mainland Africa, Morocco. The REE concentration took place in four stages which differ from each as with regard to their landscape and mineralogy: (1) magmatic calcic-carbonatites with REE-bearing apatite (28 to 24 Ma) (2) calcic-carbonatites, alkali magmatites with REE phosphate and carbonates (contact-metamorphic - metasomatic, epithermal) (19 to 4 Ma) (3) alkali magmatites with hydroxyl-group-bearing REE phosphates, REE oxides, Fe oxide, Fe-Cu sulfides, kaolinite-halloysite, and REE-APS minerals (epithermal) (5 to 0.3 Ma) (4) pyroclastic and volcanic rocks with smectite, kaolinite, REE-bearing silicates and oxides (auto-metasomatic) and a variegated series of more than 100 REE-, Nb-, F-, Zr-, Li- and Be minerals which are diagnostic for carbonatite- and/or alkali-magmatites pegmatitic systems at depth (<0.6 Ma). This REE mineralization of the CIA extending into on-shore Morocco is akin to the REE mineralization recorded from titanomagnetite–magnetite–apatite-REE- deposits in carbonatite-alkaline complexes in N Europe with the reference catena-deposits Kiruna-Sokli-Chibina (Sweden, Finland, Russia). The NNW African REE metallogenic province shows from E to W four geodynamic zones: ... |
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