Project Details
Projekt
Depth controlled fluid mediated metal distribution in alkaline-carbonatite magmatic systems
Subject Area
Mineralogy, Petrology and Geochemistry
Term
since 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 521625502
Alkaline and carbonatite magmas form intrusive bodies with marked vertical zonation of magmatic rocks as well as of associated rare metal deposits. Elements like Nb, Zr, Hf, REE or Ti are enriched and vertically distributed by magmatic fractionation and magmatic fluids expelled at different intrusive depths. Post-magmatic superimposition and overprinting of magmatic mineral phase assemblages by fluids convectively transported through the wall rock around the cooling intrusion has a significant impact on metal distribution. A comprehensive understanding of the melt and fluid-mediated metal enrichment and ore formation requires direct in-situ determination of ore forming rare metals in melt and fluid inclusions characteristic of the entire range of ultrabasic-alkaline-carbonatite suites and the entire depth spectrum of their complex intrusive bodies, as well as consideration of the potential role of externally derived fluids in post-magmatic metal remobilization. For this project, petrologically well characterized samples representative of the lithologic range from complexes with different intrusive depths (i.e. Lesnaya Varaka, Afrikanda, Ozernaya Varaka, Lueshe, Alnö, Sokli and Kalkfeld) are selected. Fluid and melt compositions will be determined using microthermometry, Raman spectroscopy, electron microprobe analysis and LA-ICP-MS inclusion microanalysis. The rare metal fluid and melt compositional data will be complemented by state-of-the-art triple halogen (Cl-Br-I) analysis of fluid inclusions, as well as SIMS halogen analysis of apatite (F-Cl-Br-I and δ37Cl), to facilitate fluid provenance studies. In combination, this approach promises to lead to a comprehensive understanding of rare metal transport, enrichment and remobilization in complex alkaline-carbonatite fluid systems evolving from magmatic to hydrothermal temperatures, which would also be highly beneficial for exploration targeting, improving mineral resource models and the sustainable production for the production of critical metals of high societal relevance.
DFG Programme
Priority Programmes
Subproject of
SPP 2238:
Dynamics of Ore-Metals Enrichment - DOME
International Connection
Sweden
Co-Investigators
Professor Dr. Ulrich Kramm; Professor Dr. Thomas Wagner
Cooperation Partners
Dr. Stefan Andersson; Professor Martin Whitehouse, Ph.D.
