Original paper

Oxygen isotope fractionation between fluorphlogopite and calcite: an experimental investigation of temperature dependence and F-/OH- effects

Fortier, Steven M.; Lüttge, Andreas; Satir, Muharrem; Metz, Paul

European Journal of Mineralogy Volume 6 Number 1 (1994), p. 53 - 66

48 references

published: Feb 4, 1994
manuscript accepted: Sep 17, 1993
manuscript received: May 10, 1993

DOI: 10.1127/ejm/6/1/0053

BibTeX file

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Abstract

Abstract The fractionation of oxygen isotopes between fluorphlogopite and calcite has been measured experimentally at high temperature and pressure (400-800oC, 11 kbar) by the direct exchange technique, using a pistoncylinder apparatus. The fractionation is described by the following equation: 1000 In αFphi - Cc = 0.43 - (1.84 x 106)/T2. This equation, when combined with a published relationship for quartz-calcite, yields calculated temperatures that are, on average, 30 % lower than those obtained from an empirical quartz-biotite calibration which has commonly been used in the past. Correlations between oxygen isotope fractionation and mean oxygen electrostatic site potentials demonstrate that both the magnitude and the temperature dependence of the fractionation measured in this study are consistent with the data for six other minerals calibrated using the same experimental technique. Experimental uncertainties preclude a definitive statement with regard to the magnitude of the fractionation between oxygens in the hydroxyl sites and those in the rest of the mineral structure. A comparison of the experimental data with model values, however, suggests that the differences are qualitatively consistent with those determined using a partial fluorination analytical technique

Keywords

oxygen-isotopefractionationfluorphlogopitegeothermometry