Density calculations for silicate liquids. I revised method for aluminosilicate compositions

Yan Bottinga (1) , D. Weil (2) , Pascal Richet (1)

1 IPGP - Institut de Physique du Globe de Paris
2 University of Oregon, Eugene 97403 Paris France

Equations are developed for calculating the density of aluminosilicate liquids as a function of composition and temperature. The mean molar volume at reference temperature Tr, is given by , where the summation is taken over all oxide components except A12O3, X stands for mole fraction, terms are constants derived independently from an analysis of volume-composition relations in alumina-free silicate liquids, and is the composition-dependent apparent partial molar volume of Al2O3. The thermal expansion coefficient of aluminosilicate liquids is given by , where terms are constants independent of temperature and composition, and is a composition-dependent term representing the effect of Al2O3 on the thermal expansion. Parameters necessary to calculate the volume of silicate liquids at any temperature T according to V(T) = Vrexp[α(T-Tr)], where Tr = 1400°C have been evaluated by least-square analysis of selected density measurements in aluminosilicate melts. Mean molar volumes of aluminosilicate liquids calculated according to the model equation conform to experimentally measured volumes with a root mean square difference of 0.28 and an average absolute difference of 0.90% for 248 experimental observations. The compositional dependence of is discussed in terms of several possible interpretations of the structural role of Al3+ in aluminosilicate melts.

Domaines: Planète et Univers [physics]

Yan Bottinga, D. Weil, Pascal Richet. Density calculations for silicate liquids. I revised method for aluminosilicate compositions. Geochimica et Cosmochimica Acta, 1982, 46 (6), pp.909-919. ⟨10.1016/0016-7037(82)90047-3⟩. ⟨insu-01442544⟩