Fluid Dynamic Properties of Rhyolitic Magmas, Mineral Mountains, Utah. Part I: Volatile Content and Flow Characteristics. Part II: Physical Properties

摘要

Rhyolites from southwestern Utah are described that display striking dissimilarities in morphology which are attributed to viscosity differences due to variations in water content. Temperature effects and fluorine concentrations are unable to account for the observed differences in morphology. Fluid dynamic calculations indicate that rhyolite flows of fluid aspect contained between 1 and 3 percent water upon eruption. More viscous domes contained less water which was expelled in pyroclastic eruptions preceeding emplacement of the domal rhyolite magma. The results of calculations are presented that determine the physical properties of rhyolite magmas in the Mineral Mountains. Data are presented on density, molar volume, heat capacity, gram formula mass, dynamic viscosity, thermal conductivity, thermal diffusivity, kinematic viscosity, and coefficient of thermal expansion. (ERA citation 05:011808)