The involvement of F CO.sub.2./sub., and As in the alteration of Zr-Th-REE-bearing accessory minerals in a the Hora Svaté Kateřiny A-type granite, Czech Republic

0338926 - GLÚ 2010 RIV CA eng J - Journal Article
Breiter, Karel - Čopkajová, R. - Škoda, R.
The involvement of F CO₂, and As in the alteration of Zr-Th-REE-bearing accessory minerals in a the Hora Svaté Kateřiny A-type granite, Czech Republic.
Canadian Mineralogist. Roč. 47, č. 6 (2009), s. 1375-1398. ISSN 0008-4476. E-ISSN 1499-1276
R&D Projects: GA AV ČR IAA300130801
Institutional research plan: CEZ:AV0Z30130516
Keywords : zircon * thorite * monazite * xenotime * håleniusite * granite * solid solution * Erzgebirge ( Czech Republic)
Subject RIV: DB - Geology ; Mineralogy
Impact factor: 1.290, year: 2009

The assemblage of Zr(Hf)-Th(U)-REE minerals from an A-type granite from Hora Svaté Kateřiny were studied to distinguish magmatic and hydrothermal processes affected the rock. The primary accessory phases included fluorite, magnetite, zircon, xenotime, monazite, and thorite. Solid solutions of (Th+U)-, (Zr+Hf)- and REE-components formed domains within zircon and thorite crystals and are supposed to by primary. Pyrite and arsenopyrite crystallised from the first portion of hydrothermal fluid with low oxygen fugacity. Later, fluid with higher oxygen fugacity altered magnetite, sulphides, and dissolved xenotime. During this time, Th and U-bearing zircon and thorite were partially metamictised. Arsenic was oxidised to As⁵⁺ and intensively metasomatised xenotime, Y-rich zircon and thorite forming chernovite. Even later, fluid rich in CO₂ dissolved metamictised thorite and partially dissolved monazite after only short transport at the contact with fluorite crystallised Th-rich bastnäsite.
Permanent Link: http://hdl.handle.net/11104/0182576