Experimental Studies of Melting and Crystallization Processes in Planetary Interiors
Michael Krawczynski, Ph.D., 2011
Timothy Grove, Advisor
Melting and crystallization processes on the Earth and Moon are explored in three geologic environments: the Moon's mantle, the Greenland ice-sheet, and the Earth's crust. Experiments have been conducted to determine the conditions of origin for lunar high-titanium magmas. The source regions for the high-Ti lunar magmas are distributed both laterally and vertically within the lunar mantle, and the pre-eruptive oxygen fugacity must be known to determine the true depth of origin. Chapter 3 models the behavior of water flow through the Greenland ice sheet driven by hydro-fracture of water through ice. The results show that melt water in the ablation zone of Greenland has almost immediate access to the base of the ice sheet in areas with up two kilometers of ice. Chapter 4 is an experimental study of two hydrous mantle melts from the Mt. Shasta, CA region. A new geobarometer-hygrometer based on amphibole Mg# is calibrated. In Chapter 5 the barometer is applied to a suite of mafic enclaves from Mt. Shasta. Evidence for pre-eruptive H2O contents of up to 14wt% is presented. Bulk chemical analyses of the inclusions show that magma mixing has occurred at all crustal depths up to 35km beneath Mt. Shasta.