Informace o publikaci
Pegmatite REE-mineral association from the Kroushev Dol base metal deposit (south Bulgaria): mineral replacements and timing of formation
| Autoři | |
|---|---|
| Rok publikování | 2023 |
| Druh | Článek ve sborníku |
| Konference | 17th Biennial SGA Meeting - Proceedings Volume 1 |
| Fakulta / Pracoviště MU | |
| Citace | |
| www | https://www.e-sga.org/fileadmin/PDF/Conference_proceedings/Zuerich/SGA_2023_Zurich_Volume_1.pdf |
| Klíčová slova | Central Rhodopes; Pb-Zn deposits; Madan district; South Bulgaria |
| Popis | The region of the Central Rhodopes, south Bulgaria, is known for large Pb-Zn deposits located in the Madan and Laki districts. The economic sulphide mineralization is hosted by the high-grade rocks of the Rhodope metamorphic complex. Mining operations revealed that pegmatite injections into the host gneisses, amphibolites and marbles represent a substantial part of the wall rocks in depth. Mineral composition of these dykes is represented by K-feldspar, plagioclases, and quartz as major constituents. In the pegmatites from the Kroushev Dol deposit (Madan district), REE-bearing mineralization includes accessory monazite, zircon, apatite, allanite, titanite, and thorite. Primary minerals of REE are monazite (LREE) and zircon (HREE); the REE were consequently redistributed among secondary apatite, allanite, thorite, and titanite. Common mineral breakdowns (e.g. oligoclase to albite; monazite to apatite; allanite to epidote; titanite to anatase) and replacement of the primary pegmatite minerals by the epidote-chlorite-carbonate association were caused by hydrothermal alteration by acid Pb-Zn ore-precipitating fluids. There seems to be no genetic link between the pegmatite emplacement and the economic galena-sphalerite accumulations and the U-Pb geochronometry on monazite, zircon and titanite proved that pegmatite formation (similar to 40 Ma) significantly precedes the origin of the base metal mineralization (similar to 30 Ma). |
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