Experimental studies of melting and crystallization processes in planetary interiors
Krawczynski, Michael J.
MetadataShow full item record
Mt. Shasta, CA
Melting and crystallization processes on the Earth and Moon are explored in this thesis, and the topics of melt generation, transport, and crystallization are discussed in three distinct 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 two high-titanium magmas from the Moon. The lunar experiments (Chapter 2) were designed to explore the e ects of variable oxygen fugacity (fO2) on the high pressure and high temperature crystallization of olivine and orthopyroxene in high-Ti magmas. The results of these experiments showed that the source regions for the high-Ti lunar magmas are distributed both laterally and vertically within the lunar mantle, and that it is critical to estimate the pre-eruptive oxygen fugacity in order to determine true depth of origin for these magmas within the lunar mantle. Chapter 3 models the behavior of water ow through the Greenland ice sheet driven by hydrofracture 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 high-silica mantle melts from the Mt. Shasta, CA region. Crystallization is simulated at H2O saturated conditions at all crustal depths, and a new geobarometerhygrometer based on amphibole magnesium number is calibrated. In Chapter 5 I use the new barometer to study a suite of ma c enclaves from the Mt. Shasta region, and apply it to amphiboles in these enclaves. Evidence for pre-eruptive H2O contents of up to 14 wt% is presented, and bulk chemical analyses of the inclusions are used to show that extensive magma mixing has occurred at all crustal depths up to 35km beneath Mt. Shasta.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2011
Showing items related by title, author, creator and subject.
Filiberto, Justin; Wood, Justin; Dasgupta, Rajdeep; Shimizu, Nobumichi; Le, Loan; Treiman, Allan H. (2012-03-26)Volatile species (H2O, CO2, F, Cl, etc) have important effects on the formation and crystallization history of basaltic magmas. Here, we have experimentally investigated the effects of F on phase equilibria of Fe-Mg-rich ...
Barry, Edward; Hensel, Zach; Dogic, Zvonimir; Shribak, Michael; Oldenbourg, Rudolf (American Physical Society, 2006-01-11)We study the liquid-crystalline phase behavior of a concentrated suspension of helical flagella isolated from Salmonella typhimurium. Flagella are prepared with different polymorphic states, some of which have a pronounced ...
Magmatic processes in developing oceanic crust revealed in a cumulate xenolith collected at the East Pacific Rise, 9°50′N Ridley, W. Ian; Perfit, Michael R.; Smith, Matthew C.; Fornari, Daniel J. (American Geophysical Union, 2006-12-12)The petrology and geochemistry of a xenolith, a fragment of a melt-bearing cumulate, within a recently erupted mid-ocean ridge (MOR) lava flow provide information on petrogenetic processes occurring within the newly forming ...