Skip to Main Content
GEOREF RECORD

Metamorphic-hydrothermal REE minerals in the Bacuch magnetite deposit, Western Carpathians, Slovakia; (Sr, S)-rich monazite-(Ce) and Nd-dominant hingganite

Jaroslav Prsek, Martin Ondrejka, Peter Bacik, Bartosz Budzyn and Pavel Uher
Metamorphic-hydrothermal REE minerals in the Bacuch magnetite deposit, Western Carpathians, Slovakia; (Sr, S)-rich monazite-(Ce) and Nd-dominant hingganite
The Canadian Mineralogist (February 2010) 48 (1): 81-94

Abstract

Accessory REE minerals occur in a small metamorphic magnetite ore deposit at Bacuch, Veporic Superunit, central Slovakia. We distinguish two populations of monazite. Monazite I forms subhedral to euhedral crystals associated with magnetite. It contains < or =12 wt.% ThO (sub 2) , < or =2.7% UO (sub 2) , < or =0.85% SO (sub 3) , with low Ca and Sr contents. Compared to the common monazite-(Ce) I, monazite-(Nd) I (< or =26.1% Nd (sub 2) O (sub 3) ) occasionally occurs with an atomic ratio Nd:Ce up to 1.17. Monazite II is present as irregular aggregates with hingganite in younger hydrothermal quartz-albite-chlorite veinlets, or as rim zones on monazite I. Monazite II is depleted in Th and U and has an unusually high content of S (< or =11.3% SO (sub 3) , 0.31 apfu S) and Sr (< or =8.7% SrO, 0.18 apfu Sr). This composition indicates a (Ca,Sr)S(REE,Y) (sub -1) P (sub -1) substitution as a dominant mechanism of Sr and S entry into the monazite structure. Some monazite II crystals display an elevated Eu content (< or =1.2% Eu (sub 2) O (sub 3) ). Xenotime-(Y) forms subhedral crystals, in association with monazite-(Ce) I, magnetite, pyrite transformed to goethite (?) and quartz. Gadolinite-group minerals at Bacuch are represented by hingganite with an atomic value of (super X) []/ (super X) ([]+Fe) in the range 0.51-0.72. Neodymium is locally the most abundant REE (17.8-18.7% Nd, approximately 0.56 apfu), and an Nd-dominant member of the gadolinite group was identified. The composition of hingganite-(Y) was also determined. The principal mechanism of substitution in hingganite is Fe (super 2+) O (sub 2) [] (sub -1) (OH) (sub -2) . Primary monazite I and xenotime are most likely products of regional metamorphism, together with magnetite mineralization. On the contrary, Sr- and S-rich monazite II and hingganite originated during a younger (Alpine) metamorphic-hydrothermal overprint in a fluid-rich regime.


ISSN: 0008-4476
EISSN: 1499-1276
Coden: CAMIA6
Serial Title: The Canadian Mineralogist
Serial Volume: 48
Serial Issue: 1
Title: Metamorphic-hydrothermal REE minerals in the Bacuch magnetite deposit, Western Carpathians, Slovakia; (Sr, S)-rich monazite-(Ce) and Nd-dominant hingganite
Affiliation: Comenius University, Department of Mineralogy and Petrology, Bratislava, Slovakia
Pages: 81-94
Published: 201002
Text Language: English
Publisher: Mineralogical Association of Canada, Ottawa, ON, Canada
References: 39
Accession Number: 2010-047886
Categories: General mineralogy
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 3 tables
N48°04'60" - N49°55'00", E16°49'60" - E22°30'00"
Secondary Affiliation: Polish Academy of Sciences, POL, Poland
Country of Publication: Canada
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, copyright, Mineralogical Association of Canada. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201026
Close Modal

or Create an Account

Close Modal
Close Modal