DETERMINATION OF VISCOSITIES OF A MELT OF GRANITIC COMPOSTTION AT DIFFERENT TEMPERATURES UNDER ATMOSPHERIC PRESSURE

Abstract

The viscosity (,) of silicate melts is of great interest as it not only helps to understand the emplacement of the magma coming from underneath but also gives an insight as to the structure of the melt itself. Measure- ment of I is also of theoretical interest as it is possible to determine such physical properties of the liquid as its activation energy and density. A tourmaline-muscovite granite obtained from Gangotri area, Uttarkashi district of the Central Himalayas, was fused at 1250°C and its viscosity was measured at diffe-rent temperatures with the falling sphere method, 1. to see the effect of temperature on the viscosity of the liquid, 2. to determine the activation energy of the melt of granitic composition from the Gangotri area, and 3. to compare the values of 1, as a function of temperature with those of the silicate melts of variable composition from different areas so as to have an idea regarding the rate of migration of the granitic magma in this particular area.............