|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Lakehead University, Department of Geology, Thunder Bay, ON, Canada
Apatite-dolomite carbonatite at Lesnaya Varaka. Kola Peninsula, Russia, hosts intricate mineral intergrowths composed of lueshite in the core and pyrochlore-group minerals in the rim. Lueshite is a primary Nb-bearing phase in the carbonatite and ranges in composition from certain lueshite to almost pure NaNbO 3 . For comparison, the compositional variation of lueshite from the Kovdor and Sallanlatvi carbonatites is described. At Lesnaya Varaka, lueshite is replaced by nearly stoichiometric Na-Ca pyrochlore due to late-stage re-equilibration in the carbonatite system. X-ray powder diffraction data for both minerals are presented. Barian strontiopyrochlore, occurring as replacement mantles on Na-Ca pyrochlore, contains up to 43% Sr and 8-18% Ba at the A-site, and shows a high degree of hydration and strong ionic deficiency at the A- and Y-sites. This mineral is metamict and, upon heating, recrystallises to an aeschynite-type structure. Monazite-(Ce) found as minute crystals in fractures, represents the solid solution between monazite-(Ce) CePO 4 , brabantite CaTh(PO 4 ) 2 and SrTh(PO 4 ) 2 . Our data indicate the high capacity of the monazite structure for Th and accompanying divalent cations at low temperatures and pressures that has a direct relevance to solving the problem of long-term conservation of radioactive wastes. Monazite-(Ce) and barian strontiopyrochlore are products of low-temperature hydrothermal or secondary (hypergene) alteration of the primary mineral assemblage of the carbonatite.
This record provided courtesy of AGI/GeoRef.
This article has been cited by other articles:
|
|
 |
|
  K. Linthout TRIPARTITE DIVISION OF THE SYSTEM 2REEPO4 - CaTh(PO4)2 - 2ThSiO4, DISCREDITATION OF BRABANTITE, AND RECOGNITION OF CHERALITE AS THE NAME FOR MEMBERS DOMINATED BY CaTh(PO4)2 Can Mineral, June 1, 2007; 45(3): 503 - 508. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Monchoux, F. Fontan, P. De Parseval, R. F. Martin, and R. C. Wang IGNEOUS ALBITITE DIKES IN OROGENIC LHERZOLITES, WESTERN PYRENEES, FRANCE: A POSSIBLE SOURCE FOR CORUNDUM AND ALKALI FELDSPAR XENOCRYSTS IN BASALTIC TERRANES. I. MINERALOGICAL ASSOCIATIONS Can Mineral, August 1, 2006; 44(4): 817 - 842. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Krenn, E. Krenn, and F. Finger Metamorphic formation of Sr-apatite and Sr-bearing monazite in a high-pressure rock from the Bohemian Massif American Mineralogist, August 1, 2004; 89(8-9): 1323 - 1329. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. R. Lumpkin, K. L. Smith, R. Giere, and C. T. Williams Geochemical behaviour of host phases for actinides and fission products in crystalline ceramic nuclear waste forms Geological Society, London, Special Publications, January 1, 2004; 236(1): 89 - 111. [Abstract] [PDF]
|
|
|
|
 |
|
 D. Read and C. T. Williams Degradation of phosphatic waste forms incorporating long-lived radioactive isotopes Mineralogical Magazine, October 1, 2001; 65(5): 589 - 601. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Aurisicchio, C. De Vito, V. Ferrini, and P. Orlandi Nb-Ta oxide minerals from miarolitic pegmatites of the Baveno pink granite, NW Italy Mineralogical Magazine, August 1, 2001; 65(4): 509 - 522. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. V. KRIVOVICHEV, A. R. CHAKHMOURADIAN, R. H. MITCHELL, S. K. FILATOV, and N. V. CHUKANOV Crystal structure of isolueshite and its synthetic compositional analogue European Journal of Mineralogy, June 1, 2000; 12(3): 597 - 607. [Abstract] [Full Text] [PDF]
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
