Matches in SemOpenAlex for { <https://semopenalex.org/work/W11382812> ?p ?o ?g. }
Showing items 1 to 57 of
57
with 100 items per page.
- W11382812 abstract "Baddeleyite is a frequently found accessory mineral in silica-undersaturated lavas. Because it is typically enriched in uranium, while having low initial lead, baddeleyite has long been a prime target for U-Pb geochronology for mafic rocks. The difficulties in retrieving small baddeleyite grains from volcanic samples and the lack of a detailed understanding of baddeleyite occurrence, however, have limited baddeleyite chronology largely to coarse-grained mafic intrusive rocks. In this thesis, the development of U-Th in-situ baddeleyite analysis using Secondary Ionization Mass Spectrometry (SIMS) is presented together with an assessment of baddeleyite occurrence in Quaternary silica-undersaturated lavas. Samples studied include the Cathedral Crag and Burroughs Mountain lava flows of Cascade arc volcanoes Mt. Baker and Mt. Rainier (Washington, USA), respectively, and Accademia, Punta Marmolite and Cuma lava domes of the Campi Flegrei caldera (Naples, Italy). Baddeleyite crystals were initially identified in cut and polished rock billets using scanning electron microscope (SEM) backscatter imaging and energy dispersive x-ray analysis, before they were separated by diamond-drilling for SIMS analysis. A total of 62 and 52 baddeleyite crystals were documented from Cathedral and Burroughs Mountain lava flows; 205, 42 and 15 baddeleyite crystals were documented from Accademia, Punta Marmolite and Cuma lava domes, respectively. U-Th baddeleyite isochron ages range between near secular equilibrium for Cathedral Crag lava flow: 404.5 - 197.8 + i ka (MSWD = 0.88; n = 3); and 4.36 - 1.12 + 1.13 ka (MSWD = 2.9; n = 24) for the Accademia lava dome. The ages for Punta Marmolite ( 62.4 - 3.9 + 3.8 ka; MSWD = 1.2; n = 11) and Cuma ( 45.9 - 3.5 + 3.6 ka; MSWD = 2.2; n = 11) fall in between, and are in a favorable age range for U-Th dating approximately near one half-life of 230 Th (~75.69 ka). Burroughs Mountain lava was not dated because it is expected to be in secular equilibrium, but it was used to monitor the abundance of baddeleyite in basaltic andesite from an arc volcano. The U-Th baddeleyite ages generally agree with previously reported K-Ar ages, except for the Punta Marmolite lava flow, which has a significantly older U-Th baddeleyite age compared to the K-Ar age. The age comparisons suggest that baddeleyite overwhelmingly crystallized near the time of eruption, in contrast to the frequently observed protracted pre-eruptive residence of zircon in silicic volcanic rocks. Near-eruption crystallization is supported by observations that ~50% of baddeleyite crystals occur at the walls of vesicles in most lavas studied here, including Punta Marmolite lava flow. The apparent hiatus between baddeleyite crystallization and eruption in Punta Marmolite thus could reflect a bias in the K-Ar age. U-Th baddeleyite dating is demonstrated to be a reliable chronometer for Quaternary silica-undersaturated volcanic rocks, and thus can be the primary dating technique for rocks that lack other datable minerals." @default.
- W11382812 created "2016-06-24" @default.
- W11382812 creator A5018693940 @default.
- W11382812 date "2014-01-01" @default.
- W11382812 modified "2023-09-26" @default.
- W11382812 title "Development of baddeleyite as a chronometer for recent silica-undersaturated lavas" @default.
- W11382812 hasPublicationYear "2014" @default.
- W11382812 type Work @default.
- W11382812 sameAs 11382812 @default.
- W11382812 citedByCount "0" @default.
- W11382812 crossrefType "journal-article" @default.
- W11382812 hasAuthorship W11382812A5018693940 @default.
- W11382812 hasConcept C113754120 @default.
- W11382812 hasConcept C120806208 @default.
- W11382812 hasConcept C127313418 @default.
- W11382812 hasConcept C167284885 @default.
- W11382812 hasConcept C17409809 @default.
- W11382812 hasConcept C199289684 @default.
- W11382812 hasConcept C202746551 @default.
- W11382812 hasConcept C2778849375 @default.
- W11382812 hasConcept C2780981397 @default.
- W11382812 hasConceptScore W11382812C113754120 @default.
- W11382812 hasConceptScore W11382812C120806208 @default.
- W11382812 hasConceptScore W11382812C127313418 @default.
- W11382812 hasConceptScore W11382812C167284885 @default.
- W11382812 hasConceptScore W11382812C17409809 @default.
- W11382812 hasConceptScore W11382812C199289684 @default.
- W11382812 hasConceptScore W11382812C202746551 @default.
- W11382812 hasConceptScore W11382812C2778849375 @default.
- W11382812 hasConceptScore W11382812C2780981397 @default.
- W11382812 hasLocation W113828121 @default.
- W11382812 hasOpenAccess W11382812 @default.
- W11382812 hasPrimaryLocation W113828121 @default.
- W11382812 hasRelatedWork W1968740413 @default.
- W11382812 hasRelatedWork W1978100541 @default.
- W11382812 hasRelatedWork W1993749617 @default.
- W11382812 hasRelatedWork W1995382732 @default.
- W11382812 hasRelatedWork W2001904234 @default.
- W11382812 hasRelatedWork W2002586037 @default.
- W11382812 hasRelatedWork W2003919078 @default.
- W11382812 hasRelatedWork W2025324534 @default.
- W11382812 hasRelatedWork W2027720889 @default.
- W11382812 hasRelatedWork W2029471854 @default.
- W11382812 hasRelatedWork W2039619662 @default.
- W11382812 hasRelatedWork W2052332245 @default.
- W11382812 hasRelatedWork W2062764503 @default.
- W11382812 hasRelatedWork W2065991425 @default.
- W11382812 hasRelatedWork W2072626791 @default.
- W11382812 hasRelatedWork W2089132493 @default.
- W11382812 hasRelatedWork W2108690791 @default.
- W11382812 hasRelatedWork W2133621845 @default.
- W11382812 hasRelatedWork W2301499839 @default.
- W11382812 hasRelatedWork W2323915547 @default.
- W11382812 isParatext "false" @default.
- W11382812 isRetracted "false" @default.
- W11382812 magId "11382812" @default.
- W11382812 workType "article" @default.