Zr-U-Th-Phases in Clinohumite-Spinel-Bearing Marbles as Potential Tracers of HFSE-Fertile Granitic Rocks
| Authors | |
|---|---|
| Year of publication | 2025 |
| Type | Article in Proceedings |
| Conference | 18th SGA Biennial Meeting 2025, Volume 2 |
| MU Faculty or unit | |
| Citation | |
| web | https://www.e-sga.org/publications/conference-proceedings |
| Keywords | Zr-U-Th phases; marbles; clinohumite; HFSE; exploration; fertile granites |
| Attached files | |
| Description | Abundant clinohumite-spinel-bearing marbles in the eastern part of the Moldanubian Zone of the Bohemian Massif (Czech Republic) typically host Zr-U-Th phase assemblages involving zirconolite, baddeleyite, zircon, uranothorite and thorianite. Although the provenance of the HFSE source is generally considered inside the marbles, usually of detrital and/or metamorphic origin, our current observations suggest the import of Zr, U and Th from an external source. The textural features and chemical composition of the Zr-U-Th phases point towards the influx of late-magmatic hydrothermal fluids most likely generated during the emplacement of the HFSE-fertile durbachite plutons from the Moldanubian Zone, in line with previous EMP chemical dating of zirconolite from the marbles. Accordingly, common occurrences of F-rich clinohumite, phlogopite and fluorapatite in the studied marbles possibly reflect infiltration of F-, K-and P-rich fluids that may represent crucial complexing ligands for fluid-driven HFSE mobilization. Taken together, this case study suggests that hydrothermally-derived Zr-U-Th minerals in metacarbonates can be used as potential tracers of HFSE-fertile granitic rocks, which can play a crucial role in the future exploration of economically important ore deposits worldwide. |
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