Rare Earth Elements and Their Minerals

0531099 - ÚSMH 2021 RIV GB eng M - Monography Chapter
René, Miloš
Allanite from granitic rocks of the Moldanubian batholith (Central European Variscan Belt).
Rare Earth Elements and Their Minerals. London: IntechOpen, 2020 - (Aide, M.; Nakajima, T.), s. 21-30. ISBN 978-1-78984-740-6
R&D Projects: GA MŠMT ME10083
Institutional support: RVO:67985891
Keywords : allanite * petrology * geochemistry * Bohemian Massif * Moldanubian Zone
OECD category: Mineralogy
https://www.intechopen.com/books/rare-earth-elements-and-their-minerals/allanite-from-granitic-rocks-of-the-moldanubian-batholith-central-european-variscan-belt-

Allanite occurs as a relative rare REE mineral in selected granitic rocks of the Moldanubian batholith. This batholith represents one of the largest plutonic bodies in the European Variscan belt. Allanite was found in the Schlieren biotite granites and diorites 1 of the oldest Weinsberg suite, in biotite granodiorites of the youngest Freistadt suite and in dykes of microgranodiorites occurred in the eastern margin of the Klenov pluton. A majority of analyzed allanites are without any magmatic zoning, only allanite grains from the diorites 1 display complicated internal zoning with variable concentrations of Fe, Ca, Th, and REE. Analyzed allanites from the Schlieren granite, diorite 1, and the “margin” variety of the Freistadt granodiorite display ferriallanite-allanite substitution with low Feox = (Fe3+/(Fe3+ + Fe2+)) ratio (0.2–0.5). The analyzed allanites occurring in the microgranodiorites display slightly greater Feox = (Fe3+/(Fe3 + Fe2+)) ratios (0.45–0.6) and enrichment in Al (up to 2.2 apfu). All analyzed allanites are Mn-poor with its concentrations from 0.01 to 0.04 apfu. The Ce is a predominant rare earth element in all analyzed allanite grains, they are thus identified as allanite-(Ce). The highest concentrations of Ce were found in allanites from diorite 1 (0.31–0.41 apfu).
Permanent Link: http://hdl.handle.net/11104/0309886