{"id":{"repo_id":"unlv","oai_identifier":"oai:oasis.library.unlv.edu:rtds-2506"},"canonical_url":"https://search.dev.ndltd.org/etd/unlv/oai:oasis.library.unlv.edu:rtds-2506","repository":{"repo_id":"unlv","name":"University of Nevada - Las Vegas","base_url":"https://oasis.library.unlv.edu/do/oai/"},"display":{"title":"Garnet-biotite thermometry, garnet-aluminum silicate-silica-plagioclase barometry, and Emp monazite geochronology of the early Proterozoic Ivanpah Mountains, eastern Mojave Desert, Se California","abstract":"Metamorphic fabric measurements indicate only one deformational fabric (NNE) is present in the Ivanpah Mountains, indicating that the area experienced one orogenic event during the Early Proterozoic. Peak P-T conditions, using garnet-Al2SiO5-silica-plagioclase barometry and garnet-biotite thermometry, were ∼4.0kb and >700°C, respectively. Peak metamorphic-T's were recorded by the largest garnet studied; Electron Microprobe Analysis on monazite, using U-Th-Pb radioactive decay, suggest metamorphism occurred between 1752 +/- 86 Ma and 1689 +/- 34 Ma, similar to the age of the Yavapai terrane (∼1.70--1.69 Ma). These ages are constrained from six monazite grains included in three large garnets (2250--5000um). Matrix monazite from granitic rocks indicate magmatism may have occurred between 1559 +/- 31 Ma and 1416 +/- 28 Ma. Large garnets effectively shield monazite from Pb-loss when temperature is exceeded above what is considered its closure-T for radiogenic-Pb (∼700°C), thus petrographic location is also a function of closure-T of radiogenic-Pb in monazite.","abstract_html":"Metamorphic fabric measurements indicate only one deformational fabric (NNE) is present in the Ivanpah Mountains, indicating that the area experienced one orogenic event during the Early Proterozoic. Peak P-T conditions, using garnet-Al2SiO5-silica-plagioclase barometry and garnet-biotite thermometry, were ∼4.0kb and >700°C, respectively. Peak metamorphic-T's were recorded by the largest garnet studied; Electron Microprobe Analysis on monazite, using U-Th-Pb radioactive decay, suggest metamorphism occurred between 1752 +/- 86 Ma and 1689 +/- 34 Ma, similar to the age of the Yavapai terrane (∼1.70--1.69 Ma). These ages are constrained from six monazite grains included in three large garnets (2250--5000um). Matrix monazite from granitic rocks indicate magmatism may have occurred between 1559 +/- 31 Ma and 1416 +/- 28 Ma. Large garnets effectively shield monazite from Pb-loss when temperature is exceeded above what is considered its closure-T for radiogenic-Pb (∼700°C), thus petrographic location is also a function of closure-T of radiogenic-Pb in monazite.","abstract_has_math":false,"creators":["Shields, David Allen"],"institution":"University of Nevada, Las Vegas","degree_name":"Master of Science (MS)","degree_level":"Thesis","degree_discipline":"Geoscience","degree_department":null,"school":null,"contributors":["Rodney Metcalf"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2003,"date_issued":"2003-01-01T08:00:00Z","date_published":"2003-01-01T08:00:00Z","updated_at":"2026-07-24T05:25:40Z","subjects":[],"languages":["English"],"rights":["IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://oasis.library.unlv.edu/rtds/1507"],"render_values":[{"text":"https://oasis.library.unlv.edu/rtds/1507","href":"https://oasis.library.unlv.edu/rtds/1507","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.25669/nrt1-1gf3","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Rodney Metcalf"]},{"key":"dc:creator","label":"Author","values":["Shields, David Allen"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["University of Nevada, Las Vegas"]},{"key":"dc:type","label":"Dc Type","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geoscience"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]},{"key":"dc:rights","label":"Dc Rights","values":["IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10.25669/nrt1-1gf3","https://oasis.library.unlv.edu/rtds/1507","https://oasis.library.unlv.edu/context/rtds/article/2506/viewcontent/uc.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Metamorphic fabric measurements indicate only one deformational fabric (NNE) is present in the Ivanpah Mountains, indicating that the area experienced one orogenic event during the Early Proterozoic. Peak P-T conditions, using garnet-Al2SiO5-silica-plagioclase barometry and garnet-biotite thermometry, were ∼4.0kb and >700°C, respectively. Peak metamorphic-T's were recorded by the largest garnet studied; Electron Microprobe Analysis on monazite, using U-Th-Pb radioactive decay, suggest metamorphism occurred between 1752 +/- 86 Ma and 1689 +/- 34 Ma, similar to the age of the Yavapai terrane (∼1.70--1.69 Ma). These ages are constrained from six monazite grains included in three large garnets (2250--5000um). Matrix monazite from granitic rocks indicate magmatism may have occurred between 1559 +/- 31 Ma and 1416 +/- 28 Ma. Large garnets effectively shield monazite from Pb-loss when temperature is exceeded above what is considered its closure-T for radiogenic-Pb (∼700°C), thus petrographic location is also a function of closure-T of radiogenic-Pb in monazite."]},{"key":"dc:format","label":"Dc Format","values":["pdf"]},{"key":"dc:title","label":"Title","values":["Garnet-biotite thermometry, garnet-aluminum silicate-silica-plagioclase barometry, and Emp monazite geochronology of the early Proterozoic Ivanpah Mountains, eastern Mojave Desert, Se California"]}]}],"canonical_facts":{"dc:contributor":["Rodney Metcalf"],"dc:creator":["Shields, David Allen"],"dc:description.abstract":["Metamorphic fabric measurements indicate only one deformational fabric (NNE) is present in the Ivanpah Mountains, indicating that the area experienced one orogenic event during the Early Proterozoic. Peak P-T conditions, using garnet-Al2SiO5-silica-plagioclase barometry and garnet-biotite thermometry, were ∼4.0kb and >700°C, respectively. Peak metamorphic-T's were recorded by the largest garnet studied; Electron Microprobe Analysis on monazite, using U-Th-Pb radioactive decay, suggest metamorphism occurred between 1752 +/- 86 Ma and 1689 +/- 34 Ma, similar to the age of the Yavapai terrane (∼1.70--1.69 Ma). These ages are constrained from six monazite grains included in three large garnets (2250--5000um). Matrix monazite from granitic rocks indicate magmatism may have occurred between 1559 +/- 31 Ma and 1416 +/- 28 Ma. Large garnets effectively shield monazite from Pb-loss when temperature is exceeded above what is considered its closure-T for radiogenic-Pb (∼700°C), thus petrographic location is also a function of closure-T of radiogenic-Pb in monazite."],"dc:format":["pdf"],"dc:identifier":["10.25669/nrt1-1gf3","https://oasis.library.unlv.edu/rtds/1507","https://oasis.library.unlv.edu/context/rtds/article/2506/viewcontent/uc.pdf"],"dc:language":["English"],"dc:publisher":["University of Nevada, Las Vegas"],"dc:rights":["IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Garnet-biotite thermometry, garnet-aluminum silicate-silica-plagioclase barometry, and Emp monazite geochronology of the early Proterozoic Ivanpah Mountains, eastern Mojave Desert, Se California"],"dc:type":["Text"],"thesis:degree_discipline":["Geoscience"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T05:25:40Z"}