Abstract
In order to assess the stability of the primary alluaudite + triphylite assemblage, we performed hydrothermal experiments between 400 and 800°C, starting from the LiNa2Mn x Fe 2+3−x Fe3+(PO4)4 compositions (x = 1.054, 1.502, 1.745) that represent the ideal compositions of the alluaudite + triphylite assemblages from the Kibingo (Rwanda), Hagendorf-Süd (Germany), and Buranga (Rwanda) pegmatites, respectively. The pressure was maintained at 1 kbar, and the oxygen fugacity was controlled by the Ni–NiO buffer. The results of these experiments show that the alluaudite + triphylite assemblage crystallizes at 400 and 500°C, while the association alluaudite + triphylite + marićite appears at 600 and 700°C. The limit between these two domains, at ca. 550°C, corresponds to the maximum temperature that can be reached by the alluaudite + triphylite assemblages in granitic pegmatites, because marićite has never been observed in such geological environments. At 800°C, the formation of the X-phase + triphylite assemblage indicates a strong reduction of the bulk composition, according to the reaction 0.5LiM2+PO4 (triphylite) + 3Na2M2 2+Fe3+(PO4)3 (alluaudite) + 1.5H2O = 4.5NaM2+PO4 (marićite) + Li0.5Na1.5M5 2+(PO4)4 (X-phase) + H3PO4 + 0.75O2 (M2+ = Fe2+, Mn). Secondary ion mass spectrometry (SIMS) was used at our knowledge for the first time to measure Li in all the Li-bearing phosphates. A specific methodological procedure was developed with the ion microprobe to get accurate Li2O data over a wide concentration range spanning from few ppm Li up to ~11 wt%. Li2O. Our SIMS analyses of the synthesized phosphates indicate that the Li contents of alluaudites, marićites, and X-phase increase progressively with temperature, while the Li content of triphylite-type phosphates decreases due to the Li → Na substitution. The Na-exchange equilibrium between triphylite-type phosphates and alluaudite is correlated with the temperature according to the equation: ln(x TriNa /x AllNa ) = −7.0(7) 103/T + 5.4(9). This equation can be used to estimate the crystallization temperature of triphylite–alluaudite assemblages independently of the oxygen fugacity.
Similar content being viewed by others
References
Baldwin JR, Von Knorring O (1983) Compositional range of Mn-garnet in zoned granitic pegmatites. Can Mineral 21:683–688
Boury P (1981) Comportement du fer et du manganèse dans les associations de phosphates pegmatitiques. Master thesis, University of Liège, p 118
Brunet F, Chopin C, Seifert F (1998) Phase relations in the MgO–P2O5–H2O system and the stability of phosphoellenbergerite: petrological implications. Contrib Mineral Petrol 131:54–70
Burke EAJ, Ferraris G, Hatert F (2006) New minerals approved in 2006, nomenclature modifications approved in 2006 by the Commission on New Minerals, Nomenclature and Classification, International Mineralogical Association. http://pubsites.uws.edu.au/ima-cnmnc/minerals2006.pdf
Burnham CW (1991) LCLSQ version 8.4, least-squares refinement of crystallographic lattice parameters. Department of Earth Planetary Sciences, Harvard University, p 24
Černý P (1991) Rare-element granitic pegmatites. Part I: anatomy and internal evolution of pegmatite deposits. Geosci Canada 18(2):49–67
Černý P, Ercit TS (2005) The classification of granitic pegmatites revisited. Can Mineral 40:2005–2026
Černý P, Meintzer RE, Anderson AJ (1985) Extreme fractionation in rare-element granitic pegmatites: selected examples of data and mechanisms. Can Mineral 23:381–421
Černý P, Ercit TS, Vanstone PT (1996) Petrology and mineralization of the Tanco rare-element pegmatite, Southeastern Manitoba. Field trip guidebook A4, Geological Association of Canada/Mineralogical Association of Canada Annual Meeting, Winnipeg, Manitoba, May 27–29, 1996, p 63
Eugster HP (1957) Heterogeneous reactions involving oxidation and reduction at high pressures and temperatures. J Chem Phys 26:1760–1761
Finger LW, Rapp GR (1969) Refinement of the crystal structure of triphylite. Carnegie Inst Wash Yearbook 68:290–292
Fisher DJ (1958) Pegmatite phosphates and their problems. Am Mineral 43:181–207
Fontan F (1978) Etude minéralogique et essais expérimentaux sur des phosphates de fer et de manganèse des pegmatites des Jebilet (Maroc) et des Pyrénées (France). PhD thesis, Université Paul-Sabatier, Toulouse, p 250
Fontan F, Huvelin P, Orliac M, Permingeat F (1976) La ferrisicklérite des pegmatites de Sidi-Bou-Othmane (Jebilet, Maroc) et le groupe des minéraux à structure de triphylite. Bull Soc française Minéral Cristall 99:274–286
Fransolet A-M (1975) Etude minéralogique et pétrologique des phosphates de pegmatites granitiques. PhD thesis, University of Liège, p 333
Fransolet A-M (1977) Le problème génétique des alluaudites. Bull Soc française Minéral Cristall 100:348–352
Fransolet A-M, Antenucci D, Speetjens J-M (1984) An X-ray determinative method for the divalent cation ratio in the triphylite-lithiophilite series. Min Mag 48:373–381
Fransolet A-M, Abraham K, Speetjens J-M (1985) Evolution génétique et signification des associations de phosphates de la pegmatite d’Angarf-Sud, plaine de Tazenakht, Anti-Atlas, Maroc. Bull Minéral 108:551–574
Fransolet A-M, Keller P, Fontan F (1986) The phosphate mineral associations of the Tsaobismund pegmatite, Namibia. Contrib Mineral Petrol 92:502–517
Fransolet A-M, Antenucci D, Fontan F, Keller P (1994) New relevant data on the crystal chemistry, and on the genetical problem of alluaudites and wyllieites. In: Abstracts of the 16th IMA general meeting, Pisa, pp 125–126
Fransolet A-M, Keller P, Fontan F (1997) The alluaudite group minerals: Their crystallochemical flexibility and their modes of formation in the granite pegmatites. In: Abstracts of the meeting “Phosphates: biogenic to exotic”, London
Fransolet A-M, Fontan F, Keller P, Antenucci D (1998) La série johnsomervilleite-fillowite dans les associations de phosphates de pegmatites granitiques de l’Afrique centrale. Can Mineral 36:355–366
Fransolet A-M, Hatert F, Fontan F (2004) Petrographic evidence for primary hagendorfite in an unusual assemblage of phosphate minerals, Kibingo granitic pegmatite, Rwanda. Can Mineral 42:697–704
Geller S, Durand JL (1960) Refinement of the structure of LiMnPO4. Acta Cryst 13:325–331
Hatert F (2002) Cristallochimie et synthèse hydrothermale d’alluaudites dans le système Na-Mn-Fe-P-O: contribution au problème de la genèse de ces phosphates dans les pegmatites granitiques. PhD thesis, University of Liège, p 247
Hatert F (2004) Etude cristallochimique et synthèse hydrothermale des alluaudites: contribution nouvelle au problème génétique des phosphates de fer et de manganèse dans les pegmatites granitiques et, partant, à celui de l’évolution de ces gisements. Mém Acad royale Sci Belgique, Cl Sci, Coll in-8°, 3ème série XXI: 96 p
Hatert F, Keller P, Lissner F, Antenucci D, Fransolet A-M (2000) First experimental evidence of alluaudite-like phosphates with high Li-content: the (Na1-xLix)MnFe2(PO4)3 series (x = 0 to 1). Eur J Mineral 12:847–857
Hatert F, Antenucci D, Fransolet A-M, Liégeois-Duyckaerts M (2002) The crystal chemistry of lithium in the alluaudite structure: a study of the (Na1-xLix)CdIn2(PO4)3 solid solution (x = 0 to 1). J Solid State Chem 163:194–201
Hatert F, Fransolet A-M, Maresch WV (2006) The stability of primary alluaudites in granitic pegmatites: an experimental investigation of the Na2(Mn2–2xFe1+2x)(PO4)3 system. Contrib Mineral Petrol 152:399–419
Héreng P (1989) Contribution à l’étude minéralogique de phosphates de fer et de manganèse de la pegmatite de Buranga, Rwanda. Master thesis, University of Liège, p 101
Huvelin P, Orliac M, Permingeat F (1972) Ferri-alluaudite calcifère de Sidi-bou-Othmane (Jebilet, Maroc). Notes Serv géol Maroc 32(241):35–49
Keller P, Von Knorring O (1989) Pegmatites at the Okatjimukuju farm, Karibib, Namibia. Part I: Phosphate mineral associations of the Clementine II pegmatite. Eur J Mineral 1:567–593
Lahti SI (1981) On the granitic pegmatites of the Eräjärvi area in Orivesi, southern Finland. Geological Survey Finland Bulletin 314: p 82
Le Page Y, Donnay G (1977) The crystal structure of the new mineral marićite, NaFePO4. Can Mineral 15:518–521
Lefèvre P (2002) Contribution à l’étude minéralogique et pétrographique des associations des phosphates d’aluminium des pegmatites de Rubindi et Kabilizi (Rwanda). Master Thesis, University of Liège, p 58
London D (2008) Pegmatites. The Canadian Mineralogist, Special Publication 10, p 347
London D, Wolf MB, Morgan GB, Gallego Garrido M (1999) Experimental silicate-phosphate equilibria in peraluminous granitic magmas, with a case study of the Alburquerque batholith at Tres Arroyos, Badajoz, Spain. J Petrol 40:215–240
London D, Morgan GB, Wolf MB (2001) Amblygonite-montebrasite solid solutions as monitors of fluorine in evolved granitic and pegmatitic melts. Am Mineral 86:225–233
Losey A, Rakovan J, Hughes JM, Francis CA, Dyar MD (2004) Structural variation in the lithiophilite-triphylite series and other olivine-group structures. Can Mineral 42:1105–1115
Mason B (1941) Minerals of the Varuträsk pegmatite. XXIII. Some iron-manganese phosphate minerals and their alteration products, with special reference to material from Varuträsk. Geol Fören Stockholm Förh 63:117–175
Moore PB (1971) Crystal chemistry of the alluaudite structure type: contribution to the paragenesis of pegmatite phosphate giant crystals. Am Mineral 56:1955–1975
Moore PB (1972) Natrophilite, NaMnPO4, has ordered cations. Am Mineral 57:1333–1344
Moore PB, Ito J (1979) Alluaudites, wyllieites, arrojadites: crystal chemistry and nomenclature. Mineral Mag 43:227–235
O’Neill HSC, Pownceby MI (1993) Thermodynamic data from redox reactions at high temperatures. I. An experimental and theoretical assessment of the electrochemical method using stabilized zirconia electrolytes, with revised values for the Fe-”FeO”, Co-CoO, Ni-NiO and Cu-Cu2O oxygen buffers, and new data for the W-WO2 buffer. Contrib Mineral Petrol 114:296–314
Ottolini L, Bottazzi P, Vannucci R (1993) Quantification of lithium, beryllium and boron in silicates by secondary ion mass spectrometry using conventional energy filtering. Anal Chem 65:1960–1968
Ottolini L, Camara F, Hawthorne FC, Stirling J (2002) SIMS matrix effects in the analysis of light elements in silicate minerals: Comparison with SREF and EMPA data. Am Mineral 87:1477–1485
Roda Robles E, Fontan F, Pesquera Pérez A, Keller P (1998) The Fe-Mn phosphate associations from the Pinilla de Fermoselle pegmatite, Zamora, Spain: occurrence of kryzhanovskite and natrodufrénite. Eur J Mineral 10:155–167
Roda E, Fontan F, Pesquera A, Velasco F (1996) The phosphate mineral association of the granitic pegmatites of the Fregeneda area (Salamanca, Spain). Mineral Mag 60:767–778
Schmid-Beurmann P, Hatert F (2005) Experimental Fe2+-oxidation in triphylite, LiFePO4: possible formation of ferrisicklerite and heterosite. Berichter der Deutschen Mineralogischen Gesellschaft, Beihefte zum. Eur J Mineral 17:118
Sturman BD, Mandarino JA, Corlett MI (1977) Marićite, a sodium iron phosphate from the Big Fish River area, Yukon Territory, Canada. Can Mineral 15:396–398
Tuttle OF (1949) Two pressure vessels for silicate-water studies. Geol Soc America Bull 60:1727–1729
Wasson JT (1974) Meteorites: classifications and properties. Springer, New York 327 p
Yakubovich OV, Simonov MA, Belov NV (1977) The crystal structure of a synthetic triphylite, LiFe[PO4]. Sov Phys Dokl 22:347–350
Acknowledgments
Many thanks are due to H.-J. Bernhardt, who performed the electron-microprobe analyses at the Ruhr-University of Bochum (Germany), as well as to A.-M. Fransolet, T.L. Grove, J. Webster, and an anonymous reviewer for their constructive comments. FH also thanks the F.N.R.S. (Belgium) for a position of “Chercheur qualifié” and for grants 1.5.113.05.F and 1.5.098.06.F.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by T. L. Grove.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Hatert, F., Ottolini, L. & Schmid-Beurmann, P. Experimental investigation of the alluaudite + triphylite assemblage, and development of the Na-in-triphylite geothermometer: applications to natural pegmatite phosphates. Contrib Mineral Petrol 161, 531–546 (2011). https://doi.org/10.1007/s00410-010-0547-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00410-010-0547-6