{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/27869"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/27869","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Studies of Magmatic Systems","abstract":"Two magmatic systems were investigated using different petrological tools: 1) Origin of Ponza trachyte was studied combining data from MI with trends predicted by thermodynamic modeling. MI data were compared with known phase relations in the ternary feldspar and anorthite-diopside-albite systems to constrain the parameters used in the modeling. MI data are consistent with melt evolution from a basaltic parent via a fractional crystallization mainly of pyroxene and feldspars. These data and the results from the modeling, suggest a genetic link between the Ponza trachyte and coeval alkali olivine basalts on the nearby Ventotene Island. 2) We evaluated the range of magmatic temperatures within the crystallization interval for a basanite with different olivine-spinel geothermometers. While olivine spinel pair records the evolution of the basanite during crystallization, low temperatures calculated with the geothermometers are unrealistic. This is likely due to the presence of significant amounts of Ti in our magmatic spinels. Indeed Ti is not taken into account in the geothermometers. We tested the possibility of accounting for the presence and effects of Ti using a linear correction for the Fe+2 content in our spinels. While this generated more realistic temperatures at the low end of the range, it also increased the dispersion in the data, suggesting that spinel behavior is more complex and that the presence of Ti affects content and site occupancy of other elements as well.","abstract_html":"Two magmatic systems were investigated using different petrological tools: 1) Origin of Ponza trachyte was studied combining data from MI with trends predicted by thermodynamic modeling. MI data were compared with known phase relations in the ternary feldspar and anorthite-diopside-albite systems to constrain the parameters used in the modeling. MI data are consistent with melt evolution from a basaltic parent via a fractional crystallization mainly of pyroxene and feldspars. These data and the results from the modeling, suggest a genetic link between the Ponza trachyte and coeval alkali olivine basalts on the nearby Ventotene Island. 2) We evaluated the range of magmatic temperatures within the crystallization interval for a basanite with different olivine-spinel geothermometers. While olivine spinel pair records the evolution of the basanite during crystallization, low temperatures calculated with the geothermometers are unrealistic. This is likely due to the presence of significant amounts of Ti in our magmatic spinels. Indeed Ti is not taken into account in the geothermometers. We tested the possibility of accounting for the presence and effects of Ti using a linear correction for the Fe+2 content in our spinels. While this generated more realistic temperatures at the low end of the range, it also increased the dispersion in the data, suggesting that spinel behavior is more complex and that the presence of Ti affects content and site occupancy of other elements as well.","abstract_has_math":false,"creators":["Fedele, Luca"],"institution":"Virginia Tech","degree_name":"Ph. D.","degree_level":"doctoral","degree_discipline":"Geological Sciences","degree_department":"Geological Sciences","school":null,"contributors":[],"advisors":[],"committee_chairs":["Bodnar, Robert J."],"committee_members":["Belkin, Harvey","Beard, James S.","De Vivo, Benedetto","Tracy, Robert J.","Webster, James"],"year":2002,"date_issued":"2002-05-09","date_published":"2002-05-09","updated_at":"2026-07-22T22:20:17Z","subjects":["Ponza","Melt Inclusions","Spinels","MELTS","Tahiti","Geothermometer","Thermodynamic Modeling"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-05242002-120716"],"render_values":[{"text":"etd-05242002-120716","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/27869","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Bodnar, Robert J."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Belkin, Harvey","Beard, James S.","De Vivo, Benedetto","Tracy, Robert J.","Webster, James"]},{"key":"dc:contributor.department","label":"Department","values":["Geological Sciences"]},{"key":"dc:creator","label":"Author","values":["Fedele, Luca"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:12:31Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:12:31Z","2003-06-11"]},{"key":"dc:date.issued","label":"Date","values":["2002-05-09"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geological Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Ponza","Melt Inclusions","Spinels","MELTS","Tahiti","Geothermometer","Thermodynamic Modeling"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-05242002-120716"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/27869"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Two magmatic systems were investigated using different petrological tools: 1) Origin of Ponza trachyte was studied combining data from MI with trends predicted by thermodynamic modeling. MI data were compared with known phase relations in the ternary feldspar and anorthite-diopside-albite systems to constrain the parameters used in the modeling. MI data are consistent with melt evolution from a basaltic parent via a fractional crystallization mainly of pyroxene and feldspars. These data and the results from the modeling, suggest a genetic link between the Ponza trachyte and coeval alkali olivine basalts on the nearby Ventotene Island. 2) We evaluated the range of magmatic temperatures within the crystallization interval for a basanite with different olivine-spinel geothermometers. While olivine spinel pair records the evolution of the basanite during crystallization, low temperatures calculated with the geothermometers are unrealistic. This is likely due to the presence of significant amounts of Ti in our magmatic spinels. Indeed Ti is not taken into account in the geothermometers. We tested the possibility of accounting for the presence and effects of Ti using a linear correction for the Fe+2 content in our spinels. While this generated more realistic temperatures at the low end of the range, it also increased the dispersion in the data, suggesting that spinel behavior is more complex and that the presence of Ti affects content and site occupancy of other elements as well."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:title","label":"Title","values":["Studies of Magmatic Systems"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Bodnar, Robert J."],"dc:contributor.committeemember":["Belkin, Harvey","Beard, James S.","De Vivo, Benedetto","Tracy, Robert J.","Webster, James"],"dc:contributor.department":["Geological Sciences"],"dc:creator":["Fedele, Luca"],"dc:date.accessioned":["2014-03-14T20:12:31Z"],"dc:date.available":["2014-03-14T20:12:31Z","2003-06-11"],"dc:date.issued":["2002-05-09"],"dc:description.abstract":["Two magmatic systems were investigated using different petrological tools: 1) Origin of Ponza trachyte was studied combining data from MI with trends predicted by thermodynamic modeling. MI data were compared with known phase relations in the ternary feldspar and anorthite-diopside-albite systems to constrain the parameters used in the modeling. MI data are consistent with melt evolution from a basaltic parent via a fractional crystallization mainly of pyroxene and feldspars. These data and the results from the modeling, suggest a genetic link between the Ponza trachyte and coeval alkali olivine basalts on the nearby Ventotene Island. 2) We evaluated the range of magmatic temperatures within the crystallization interval for a basanite with different olivine-spinel geothermometers. While olivine spinel pair records the evolution of the basanite during crystallization, low temperatures calculated with the geothermometers are unrealistic. This is likely due to the presence of significant amounts of Ti in our magmatic spinels. Indeed Ti is not taken into account in the geothermometers. We tested the possibility of accounting for the presence and effects of Ti using a linear correction for the Fe+2 content in our spinels. While this generated more realistic temperatures at the low end of the range, it also increased the dispersion in the data, suggesting that spinel behavior is more complex and that the presence of Ti affects content and site occupancy of other elements as well."],"dc:description.degree":["Ph. D."],"dc:identifier.other":["etd-05242002-120716"],"dc:identifier.uri":["http://hdl.handle.net/10919/27869"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Ponza","Melt Inclusions","Spinels","MELTS","Tahiti","Geothermometer","Thermodynamic Modeling"],"dc:title":["Studies of Magmatic Systems"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Geological Sciences"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Ph. D."],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:17Z"}