Boron isotopic fractionation between minerals and fluids: New insights from in situ high pressure-high temperature vibrational spectroscopic data | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  Boron isotopic fractionation between minerals and fluids: New insights from in situ high pressure-high temperature vibrational spectroscopic data

Type de publication:

Journal Article

Source:

Geochimica Et Cosmochimica Acta, Volume 69, Ticket 17, p.4301-4313 (2005)

ISBN:

0016-7037

URL:

http://www.sciencedirect.com

Mots-clés:

MOLECULES; MELT INCLUSIONS; TD SYMMETRY; PH CONTROL; ARC LAVAS

Résumé:

Equilibrium boron isotopic fractionations between trigonal B(OH)3 and tetragonal B(OH)4 aqueous species have been calculated at high P-T conditions using measured vibrational spectra (Raman and IR) and force-field modeling to compute reduced partition function ratios for B-isotopic exchange following Urey ' s theory. The calculated isotopic fractionation factor at 300 K, alpha(3/4) = 1.0176(2), is slightly lower than the formerly calculated value of alpha(3/4) = 1.0193 (Kakihana and Kotaka, 1977), due to differences in the determined vibrational frequencies. The effect of pressure on alpha(3/4) up to 10 GPa and 723 K is shown to be negligible relative to temperature or speciation (pH) effects. Implications for the interpretation of boron fractionation in experimental and natural systems are discussed. We also show that the relationship between seawater-mineral B isotope fractionation and PH can be expressed using two variables, alpha(3/4) on one hand, and the pK(a) of the boric acid-borate equilibrium on the other hand. This latter value is given by the equilibrium of boron species in water for the carbonate-water exchange, but could be governed by mineral surface properties in the case of clays. This may allow defining intrinsic paleo-pHmeters from B isotope fractionation between carbonate and authigenic minerals. Finally, it is shown that fractionation of boron isotopes can be rationalized in terms of the changes in 1) coordination of B from trigonal to tetrahedral in both fluids and minerals; and 2) the ligand nature around B from OH- in the fluid and some hydrous minerals to non-hydrogenated O in many minerals. Relationships are established that allow predicting the isotopic fractionation factor of B between minerals and fluid. Copyright (c) 2005 Elsevier Ltd.

Notes:

Geochim. Cosmochim. ActaISI Document Delivery No.: 964QETimes Cited: 5Cited Reference Count: 66Cited References:BASSETT RL, 1980, GEOCHIM COSMOCHIM AC, V44, P1151BELL RP, 1965, CHEM BORON ITS COMPO, P209BETHELL DE, 1955, T FARADAY SOC, V51, P9BIGELEISEN J, 1947, J CHEM PHYS, V15, P261CHERVIN JC, 1995, REV SCI INSTRUM, V66, P2595CHERVIN JC, 2001, HIGH PRESSURE RES, V21, P305CLAYTON RN, 1975, GEOCHIM COSMOCHIM AC, V39, P1197COTTON FA, 1980, ADV INORGANIC GEOCHEDEVINA OA, 1982, GEOCHEM INT, V19, P147EDWARDS JO, 1955, J AM CHEM SOC, V77, P266FARMER JB, 1982, ADV INORG CHEM RAD, V25, P187FELMY AR, 1986, GEOCHIM COSMOCIM ACT, V50, P2531GAILLARDET J, 1995, EARTH PLANET SC LETT, V136, P665GILLET P, 1996, GEOCHIM COSMOCHIM AC, V60, P3471GOULDEN JDS, 1959, SPECTROCHIM ACTA, V9, P657HEMMING NG, 1995, GEOCHIM COSMOCHIM AC, V59, P371HERSHEY JP, 1986, GEOCHIM COSMOCHIM AC, V50, P143HERVIG RL, 2002, AM MINERAL, V87, P769HESS AC, 1988, J PHYS CHEM-US, V92, P1785HIBBEN JH, 1939, RAMAN EFFECTS ITS CH, P430ISHIKAWA T, 1994, NATURE, V370, P205KAKIHANA H, 1977, B CHEM SOC JPN, V50, P158KAKIHANA H, 1977, B RES LAB NUCL REACT, V2, P1KREBS B, 1967, J MOL SPECTROSC, V24, P198LECUYER C, 2002, CHEM GEOL, V186, P45LEEMAN WP, 1996, SUBDUCTION TOP BOTTO, P269MAO HK, 1978, J APPL PHYS, V49, P3276MORAN AE, 1992, EARTH PLANET SC LETT, V111, P331MORRIS JD, 1990, NATURE, V344, P31MULLER A, 1967, J MOL SPECTROSC, V24, P180NAKAMOTO K, 1997, INFRARED RAMAN SPECTOI T, 1991, GEOCHEM J, V25, P377OI T, 2000, J NUCL SCI TECHNOL, V37, P166OI T, 2000, Z NATURFORSCH A, V55, P623OI T, 2001, J NUCL SCI TECHNOL, V38, P429PALMER MR, 1987, GEOCHIM COSMOCHIM AC, V51, P2319PALMER MR, 1992, CHEM GEOL, V101, P123PALMER MR, 1998, SCIENCE, V282, P1468PEAK D, 2003, GEOCHIM COSMOCHIM AC, V67, P2551PISTORIUS CWF, 1959, J CHEM PHYS, V31, P1454POLYAKOV VB, 1994, GEOCHIM COSMOCHIM AC, V58, P4739POLYAKOV VB, 1998, GEOCHIM COSMOCHIM AC, V62, P3077POPLE JA, 1993, ISRAEL J CHEM, V33, P345RAGAN DR, 1996, J APPL PHYS, V72, P5539RICHET P, 1977, ANNU REV EARTH PL SC, V5, P65ROSE EF, 2001, SCIENCE, V293, P281SANYAL A, 1995, NATURE, V373, P234SANYAL A, 1996, PALEOCEANOGRAPHY, V11, P513SANYAL A, 2000, GEOCHIM COSMOCHIM AC, V64, P1551SCHAUBLE EA, 2001, GEOCHIM COSMOCHIM AC, V65, P2487SCHAUBLE EA, 2003, GEOCHIM COSMOCHIM AC, V67, P3267SCHWARCZ HP, 1969, EARTH PLANET SC LETT, V6, P1SCOTT AP, 1996, J PHYS CHEM-US, V100, P16502SEN S, 1994, AM MINERAL, V79, P819SERVOSS RR, 1957, J CHEM PHYS, V26, P1175SHIMANOUCHI T, 1949, J CHEM PHYS, V17, P245SIEBERT H, 1966, ANWENDUNGEN SCHWINGUSPIVACK AJ, 1993, NATURE, V363, P149THIRUGNANASAMBA.P, 1969, J CHEM PHYS, V50, P2467THOMAS R, 2002, AM MINERAL, V87, P56UREY HC, 1947, J CHEM SOC, P562VENGOSH A, 1991, GEOCHIM COSMOCHIM AC, V55, P2901WILLIAMS LB, 2001, GEOCHIM COSMOCHIM AC, V65, P1769WILLIAMS LB, 2002, AM MINERAL, V87, P1564WILSON EB, 1955, MOL VIBRATIONSWUNDER B, 2004, GEOCHIM COSMOCHIM S, V68, A51