Dear Thomas and others interested, >I am looking for oxygen isotope fractionation factors between calcite and >acid-liberated CO2 at temperatures above 25°C in order to correct d18O >values of dolomite for differences in the dolomite-CO2 fractionation. >............ Also check out Swart et al. (1991; Chem. Geol. (Isotope Geosc. Sect.) V. 86, p.89-96). They compare acid fractionation factors at 25 to 90 deg C for a number of different techniques. Greetings, Torsten. ------------------------------------ Torsten W. Vennemann Institute for Geochemistry University of Tuebingen Wilhelmstr. 56 D-72074 Tuebingen Germany Tel: (0)7071 29 74992 Fax: (0)7071 29 5713 ----------------------------------