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dc.contributor.authorWeber, Rachel Maria, 1975-
dc.date.accessioned2011-11-30T00:09:51Z
dc.date.available2011-11-30T00:09:51Z
dc.date.issued2010-06
dc.identifier.urihttp://hdl.handle.net/1794/11768
dc.descriptionx, 86 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.en_US
dc.description.abstractHigh-Mg basaltic andesites and andesites occur in the central Trans-Mexican Volcanic Belt, primarily in the region south of Mexico City, and their primitive chemical characteristics suggest equilibration with mantle peridotite. These lavas may represent either slab melts that re-equilibrated with peridotite during ascent or hydrous partial melts of a peridotite source. I have experimentally mapped the liquidus mineralogy for a high-Mg andesite from the Pelagatos cinder cone as a function of temperature and H20 content over a range of mantle wedge pressures. The results,concur with a published thermo barometer for peridotite melting and suggest that this composition could only be in equilibrium with a harzburgite residue at relatively high water contents and low pressures and temperatures. However, numerically adjusting the composition fo r equilibrium with more refractory mantle (Fo92) shifts these conditions to lower water content s and higher pressures and temperatures near where geodynamic models indicate peak mantle wedge temperatures.en_US
dc.description.sponsorshipCommittee in charge: Dr. Paul J. Wallace, Chair; Dr. A. Dana Johnston; Dr. Eugene D. Humphreysen_US
dc.language.isoen_USen_US
dc.publisherUniversity of Oregonen_US
dc.relation.ispartofseriesUniversity of Oregon theses, Dept. of Geological Sciences, M.S., 2010;
dc.subjectAndesite -- Mexico -- Transverse Volcanic Range
dc.subjectTransverse Volcanic Range (Mexico)
dc.titleExperimental Insights into the Formation of High-Mg Andesites in the Trans-Mexican Volcanic Belten_US
dc.typeThesisen_US


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