Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (32) Citing Articles via Google Scholar Google Scholar Articles by Finch, R. J. Articles by Burns, P. C. Search for Related Content GeoRef GeoRef Citation

Rare-earth elements in synthetic zircon: Part 2. A single-crystal X-ray study of xenotime substitution

Robert J. Finch^1,*, John M. Hanchar^1,, Paul W. O. Hoskin^2, and Peter C. Burns³

¹ Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinios 60439, U.S.A.
² Research School of Earth Sciences, Institute of Advanced Studies, The Australian National University, Canberra ACT 0200, Australia
³ Department of Civil Engineering and Geological Sciences, University of Notre Dame, Notre Dame, Indiana 46556-0767, U.S.A.

Correspondence: ^* E-mail: finch{at}cmt.anl.gov

Zircon crystals synthesized in a Li-Mo oxide melt and doped with trivalent lanthanides and Y (REE), both with and without P, were examined by single-crystal X-ray diffraction (XRD). REE are incorporated into the Zr site in the zircon structure, and some Zr appears to be displaced to the Si site. Crystals doped with middle REE (MREE, Sm to Dy) and Y, plus P follow the xenotime substitution (REE³⁺ + P⁵⁺ = Zr⁴⁺ + Si⁴⁺) rather closely, whereas crystals doped with heavy REE (HREE, Er to Lu) deviate from the xenotime substitution, having REE:P atomic ratios significantly greater than one. Xenotime substitution requires that P⁵⁺ replace Si⁴⁺, but this substitution becomes limited by strain at the Si site in HREE-doped crystals. As Si sites become saturated with P⁵⁺, additional charge balance in synthetic zircon crystals may be provided by Mo⁶⁺ and Li⁺ from the flux entering interstitial sites, accounting for an additional 0.3 to 0.6 at% HREE beyond that balanced by P⁵⁺ ions. Heavy REE are more compatible in the zircon structure than are LREE and MREE, and HREE substitution is ultimately limited by the inability of the zircon structure to further accommodate charge-compensating elements. Thus the limit on REE concentrations in zircon is not a simple function of REE³⁺ ionic radii but depends in a complex way on structural strain at Zr and Si sites, which act together to limit REE and P incorporation. The mechanisms that limit the coupled xenotime substitution change from LREE to HREE. This change means that REE fractionation in zircon may vary according to the availability of charge-compensating elements. REE partition coefficients between zircon and melt must also depend in part on the availability of charge-compensating elements and their compatibility in the zircon structure.

This article has been cited by other articles:

				S. M. Reddy, N. E. Timms, and B. M. Eglington Electron backscatter diffraction analysis of zircon: A systematic assessment of match unit characteristics and pattern indexing optimization American Mineralogist, January 1, 2008; 93(1): 187 - 197. [Abstract] [Full Text] [PDF]

				C. Perez-Soba, C. Villaseca, J. G. Del Tanago, and L. Nasdala THE COMPOSITION OF ZIRCON IN THE PERALUMINOUS HERCYNIAN GRANITES OF THE SPANISH CENTRAL SYSTEM BATHOLITH Can Mineral, June 1, 2007; 45(3): 509 - 527. [Abstract] [Full Text] [PDF]

				R. M. Bomparola, C. Ghezzo, E. Belousova, W. L. Griffin, and S. Y. O'Reilly Resetting of the U-Pb Zircon System in Cambro-Ordovician Intrusives of the Deep Freeze Range, Northern Victoria Land, Antarctica J. Petrology, February 1, 2007; 48(2): 327 - 364. [Abstract] [Full Text] [PDF]

				M. Poujol, R. Kiefer, L.J. Robb, C.R. Anhaeusser, and R.A. Armstrong New U-Pb data on zircons from the Amalia greenstone belt Southern Africa: insights into the Neoarchaean evolution of the Kaapvaal Craton South African Journal of Geology, September 1, 2005; 108(3): 317 - 332. [Abstract] [Full Text] [PDF]

				C. Spandler, J. Hermann, and D. Rubatto Exsolution of thortveitite, yttrialite, and xenotime during low-temperature recrystallization of zircon from New Caledonia, and their significance for trace element incorporation in zircon American Mineralogist, November 1, 2004; 89(11-12): 1795 - 1806. [Abstract] [Full Text] [PDF]

				W. van Westrenen, W. Van Westrenen, M. R. Frank, J. M. Hanchar, Y. Fei, R. J. Finch, and C.-S. Zha In situ determination of the compressibility of synthetic pure zircon (ZrSiO4) and the onset of the zircon-reidite phase transition American Mineralogist, January 1, 2004; 89(1): 197 - 203. [Abstract] [Full Text] [PDF]

				F. TOMASCHEK, A. K. KENNEDY, I. M. VILLA, M. LAGOS, and C. BALLHAUS Zircons from Syros, Cyclades, Greece--Recrystallization and Mobilization of Zircon During High-Pressure Metamorphism J. Petrology, November 1, 2003; 44(11): 1977 - 2002. [Abstract] [Full Text] [PDF]

				S. Klemme, S. Klemme, and C. Dalpe Trace-element partitioning between apatite and carbonatite melt American Mineralogist, April 1, 2003; 88(4): 639 - 646. [Abstract] [Full Text] [PDF]

				R. J. Finch, R. J. Finch, and J. M. Hanchar Structure and Chemistry of Zircon and Zircon-Group Minerals Reviews in Mineralogy and Geochemistry, January 1, 2003; 53(1): 1 - 25. [Full Text] [PDF]

				P. W. O. Hoskin, P. W. O. Hoskin, and U. Schaltegger The Composition of Zircon and Igneous and Metamorphic Petrogenesis Reviews in Mineralogy and Geochemistry, January 1, 2003; 53(1): 27 - 62. [Full Text] [PDF]

				J. B. Thomas, J. B. Thomas, R. J. Bodnar, N. Shimizu, and C. A. Chesner Melt Inclusions in Zircon Reviews in Mineralogy and Geochemistry, January 1, 2003; 53(1): 63 - 87. [Full Text] [PDF]

				L. Nasdala, L. Nasdala, M. Zhang, U. Kempe, G. Panczer, M. Gaft, M. Andrut, and M. Plotze Spectroscopic methods applied to zircon Reviews in Mineralogy and Geochemistry, January 1, 2003; 53(1): 427 - 467. [Full Text] [PDF]

				Y. Moelo, Y. Lulzac, O. Rouer, P. Palvadeau, E. Gloaguen, and P. Leone SCANDIUM MINERALOGY: PRETULITE WITH SCANDIAN ZIRCON AND XENOTIME-(Y) WITHIN AN APATITE-RICH OOLITIC IRONSTONE FROM SAINT-AUBIN-DES-CHATEAUX, ARMORICAN MASSIF, FRANCE Can Mineral, December 1, 2002; 40(6): 1657 - 1673. [Abstract] [Full Text] [PDF]

				J. M. Hanchar, R. J. Finch, P. W.O. Hoskin, E. B. Watson, D. J. Cherniak, and A. N. Mariano Rare earth elements in synthetic zircon: Part 1. Synthesis, and rare earth element and phosphorus doping American Mineralogist, May 1, 2001; 86(5-6): 667 - 680. [Abstract] [Full Text] [PDF]