Contribution
Oxygen isotope fractionation in wolframite
Zheng, Yong-Fei
European Journal of Mineralogy Volume 4 Number 6 (1992), p. 1331 - 1336
17 références bibliographiques
publié: Dec 8, 1992
manuscrit accepté: Feb 13, 1992
manuscrit reçu: Apr 23, 1991
DOI: 10.1127/ejm/4/6/1331
Abstract
Abstract Thermodynamic oxygen isotope factors for wolframite are calculated using the modified increment method and assuming a predominant contribution of the 180-increment in complex anion to the I-18O index of complex mineral. The oxygen isotope fractionation factors obtained between quartz, wolframite and water are: 103In αquartz-wolframite= 0 . 3 8 X 106/T2 + 4.76 X 103 /T - 2.48 103In (αwolframite-water = 3.86 x106/T2 - 8.54 x 103/T + 1.44 for the temperature range from 0 to 1200°C. No difference in fractionation between ferberite and huebnerite is observed, indicating that the substitution of Fe for Mn does not significantly affect the 18O/16O partitioning in the wolframite series. When the present calibration for the quartz-wolframite system is applied to isotopic geothermometry in hydrothermal tungsten mineralizations, the temperatures calculated are well comparable to results from other geothermometric methods.
Mots-clefs
wolframite • scheelite • oxygen isotope fractionation factor • hydrothermal tungsten mineralization