Research
Metamict Fergusonite from Kolonna and Masimbula, Sri Lanka
Authors:
A. Erlacher,
Universitiit Wien, Althanstr. 14, A-1090, Wien, AT
About A.
Institutfar Mineralogie und Kristallographie
M. Zeug,
Universitiit Wien, Althanstr. 14, A-1090, Wien, AT
About M.
Institutfar Mineralogie und Kristallographie
R. Skoda,
Masaryk University, Kotlafska 267/2, 61137 Brno, CZ
About R.
Department of Geological Sciences, Faculty of Science
K. A. G. Sameera,
Geological Survey and Mines Bureau, 569 B120, Sri Jayawardenepura Kotte 10100, LK
About K. A. G.
Postgraduate Institute of Science, University of Peradeniya, P. 0. Box 25, Peradeniya 20400
L. Nasdala
Universitiit Wien, Althanstr. 14, A-1090, Wien, AT
About L.
Institutfar Mineralogie und Kristallographie
Abstract
Two radioactive mineral specimens (with compositions ThO2 2.9-4.6wt% and UO2 5.8-7.8wt%, respectively), collected from a placer deposit near Kolonna and a quarry near Masimbula, Sri Lank.a, were identified as metamict fergusonite. Identification was based on samples' chemical compositions and the observation that both specimens were transformed to crystalline fergusonite upon dry annealing at 550-600°C, including the spectroscopic observation of a high-temperature α---- β transition (≥750°C) that is characteristic of this mineral. Strong negative Eu anomalies in chondrite-normalised REE patterns indicate reducing formation conditions. Both samples have experienced (perhaps even multiple) chemical alteration processes that led to the formation of decidedly heterogeneous internal textures. Fluid-driven alteration, especially along fractures and domain boundaries, has resulted in vast chemical changes.
How to Cite:
Erlacher, A., Zeug, M., Skoda, R., Sameera, K.A.G. and Nasdala, L., 2021. Metamict Fergusonite from Kolonna and Masimbula, Sri Lanka. Journal of the Geological Society of Sri Lanka, 22(2), pp.1–14. DOI: http://doi.org/10.4038/jgssl.v22i2.67
Published on
30 Dec 2021.
Peer Reviewed
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