Francoisite-(Ce), a new mineral species from La Creusaz uranium deposit (Valais, Switzerland) and from Radium Ridge (Flinders Ranges, South Australia): Description and genesis


Autoria(s): Meisser N.; Brügger J.; Ansermet S.; Thélin P.; Bussy F.
Data(s)

2010

Resumo

The new mineral francoisite-(Ce), (Ce,Nd,Ca)[(UO(2))(3)O(OH)(PO(4))(2)]center dot 6H(2)O is the Ce-analog of francoisite-(Nd). It has been discovered simultaneously at the La Creusaz uranium deposit near Les Marecottes in Valais, Switzerland, and at the Number 2 uranium Workings, Radium Ridge near Mt. Painter, Arkaroola area, Northern Flinders Ranges in South Australia. Francoisite-(Ce) is a uranyl-bearing supergene mineral that results from the alteration under oxidative conditions of REE- and U(4+)-bearing hypogene minerals: allanite-(Ce), monazite-(Ce), +/- uraninite at Les Marecottes; monazite-(Ce), ishikawaite-samarskite, and an unknown primary U-mineral at Radium Ridge. The REE composition of francoisite-(Ce) results from a short aqueous transport of REE leached out of primary minerals [most likely monazite-(Ce) at Radium Ridge and allanite-(Ce) at La Creusaz], with fractionation among REE resulting mainly from aqueous transport, with only limited Ce loss due to oxidation to Ce(4+) during transport.

Identificador

http://serval.unil.ch/?id=serval:BIB_1C4E59288A38

doi:10.2138/am.2010.3413

Idioma(s)

en

Fonte

American Mineralogist, vol. 95, pp. 1527-1532

Tipo

info:eu-repo/semantics/article

article