Estimation of the viscosity and the water content of silicate melts from melt inclusion data
European Journal of Mineralogy Volume 6 Number 4 (1994), p. 511 - 535
published: Jul 27, 1994
manuscript accepted: Mar 7, 1994
manuscript received: Oct 20, 1992
ArtNo. ESP147050604012, Price: 29.00 €
Abstract This paper presents a new and simple method for the estimation of the viscosity and the water content in hydrous silicate melts using homogenization measurements on melt inclusions in rock-forming minerals in granites and rhyolites from the Erzgebirge, the Slavkovsky les, Thuringia and the Caucasus, the Fichtelgebirge, the Oberpfalz. A combination of the Stokes-Einstein equation and Shaw's (1972) viscosity calculation, together with data for the temperature, inclusion diameter, run time, and inclusion chemistry, is used. The viscosity at the minimum observable homogenization temperature is 3.6 * 104 Pas and is virtually independent of H2O content within the range 2 - 8 wt.%. Generally, the water contents range from 2.5 to 9 wt.%. The accuracy of the method and the possibility of diffusive loss of water are critically assessed.