Experimental Insights into the Formation of High-Mg Andesites in the Trans-Mexican Volcanic Belt
| dc.contributor.author | Weber, Rachel Maria, 1975- | |
| dc.date.accessioned | 2011-11-30T00:09:51Z | |
| dc.date.available | 2011-11-30T00:09:51Z | |
| dc.date.issued | 2010-06 | |
| dc.description | x, 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.abstract | High-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.sponsorship | Committee in charge: Dr. Paul J. Wallace, Chair; Dr. A. Dana Johnston; Dr. Eugene D. Humphreys | en_US |
| dc.identifier.uri | https://hdl.handle.net/1794/11768 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | University of Oregon | en_US |
| dc.relation.ispartofseries | University of Oregon theses, Dept. of Geological Sciences, M.S., 2010; | |
| dc.subject | Andesite -- Mexico -- Transverse Volcanic Range | |
| dc.subject | Transverse Volcanic Range (Mexico) | |
| dc.title | Experimental Insights into the Formation of High-Mg Andesites in the Trans-Mexican Volcanic Belt | en_US |
| dc.type | Thesis | en_US |