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dc.contributor.advisorWalker, James Allen, 1952-en_US
dc.contributor.authorKnudson, Christine A.en_US
dc.date.accessioned2017-08-02T21:16:06Z
dc.date.available2017-08-02T21:16:06Z
dc.date.issued2014
dc.identifier.urihttp://commons.lib.niu.edu/handle/10843/17715
dc.descriptionAdvisors: James A. Walker.en_US
dc.descriptionCommittee members: Justin P. Dodd; Mark R. Frank.en_US
dc.description.abstractPacaya Volcano is an active composite volcano located in southern Guatemala, about 30 km from the nation's capital, Guatemala City. This volcano has variable eruptive styles ranging from non-explosive to moderately explosive. Volcanic rocks from Pacaya are mostly basaltic to basaltic andesite and tend to be porphyritic, containing approximately 25-35% crystals, dominantly plagioclase. Previous data from olivine-hosted melt inclusions in Pacaya's tephras suggest relatively low magmatic water contents for a subduction zone volcano, particularly compared to neighboring composite volcanoes along the Central American Volcanic Arc.en_US
dc.description.abstractThe goal of this research was to use plagioclase phenocrysts in basaltic andesite lavas from Pacaya as a secondary method to verify the unusually low magmatic water contents reported previously. Water contents were estimated using a plagioclase-liquid hygrometer. Plagioclase crystals were selected from thin sections made of lavas from five different eruptive events. Phenocrysts were analyzed using the electron microprobe at Northern Illinois University. Plagioclase crystallization temperatures were obtained using a geothermometer. Water contents were calculated to be ≤ 3.6 wt. % H2O for lavas erupted from Pacaya, and are consistent with olivine-hosted melt inclusion data, but low for subduction zone volcanoes.en_US
dc.format.extent129 pagesen_US
dc.language.isoengen_US
dc.publisherNorthern Illinois Universityen_US
dc.rightsNIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.en_US
dc.subject.lcshMagmatismen_US
dc.subject.lcshGeologyen_US
dc.subject.lcshPetrologyen_US
dc.subject.lcshGeochemistryen_US
dc.subject.lcshPacaya Volcano (Guatemala)en_US
dc.titleMagmatic water content of Pacaya Volcano, Guatemala, determined from a thermodynamic model for the plagioclase-liquid hygrometeren_US
dc.typeTexten_US
dc.contributor.departmentDepartment of Geology and Environmental Sciencesen_US
dc.description.degreeM.S. (Master of Science)en_US


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