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Showing 1 to 20 of 233 for “"Zircon"”.
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Zircon behaviour in low temperature environments
Abstract Zircon in mudstones, sandstones and greenschist facies metasediments has been investigated using conventional SEM techniques (BSE, CL and SE imaging) and reveals highly variable microstructures and textures. In these rocks, zircon readily responds to low temperature events due to radiation …
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Zircon (U-Th)/He Dates from Radiation Damaged Crystals: A New Damage-He Diffusivity Model for the Zircon (U-Th)/He Thermochronometer
Zircon (U-Th)/He (zircon He) dating has become a widely used thermochronologic method in the geosciences. Practitioners have traditionally interpreted (U-Th)/He dates from zircons across a broad spectrum of chemical compositions with a single set of ⁴He diffusion kinetics derived from only a …
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A fluidized bed kinetic model for the fluorination of Zircon
Please read the abstract in the section 00front of this document
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Age determinations of Massachusetts granites from radiogenic lead in zircon
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Geology, 1955.
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Computer simulation and topological modeling of radiation effects in zircon
… on atomic level the structural response of zircon (ZrSiO4) to irradiation using molecular dynamics (MD) computer simulations, and to develop topological models that can describe these structural changes. Topological signatures, encoded using the concepts of primitive-rings and local …
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Detrital Zircon Analysis of Permian Victoria Group Sandstones, Transantarctic Mountains, Antarctica
… the sedimentary provenance further, detrital zircons have been examined from both flanks of the basin. At Clarkson Peak, samples were collected from the lower (quartzose) and upper (volcaniclastic) Buckley Formation. At Mt. Bowers the complete Permian section, from pre-glacial to upper Buckley …
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Zircon Geochronology of Ash Beds in the Marcellus Shale of the Appalachian Basin
… and Onondaga Limestone of the Appalachian basin. Zircon grains from the ash layers are suitable for SIMS U-Th-Pb geochronology due to their resistant behavior against weathering and ability to record age of the eruptions.;A total of 24 Tioga ash layers within cores of the Middle Devonian Marcellus …
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The Global Detrital Zircon Database: Quantifying the Timing and Rate of Crustal Growth
Published detrital zircon geochronological data was compiled to form the Global Detrital Zircon Database (GDZDb). This database provides a reference block for provenance analysis by future detrital zircon geochronological studies. This project entailed three subprojects: 1. crustal growth/crustal …
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Zircon crystallization patterns from U-Th dates inform U-Pb estimates of volcanic eruption ages
U-Pb dating of zircons provides time constraints on events from 4.5 Ga to < 1Ma by measuring the timing of zircon crystallization. Absolute uncertainties on U-Pb zircon dates are significant enough to obscure zircon crystallization and complicate estimating the relationship between zircon …
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Kinetic and Microstructural Aspects of Zircon Decomposition in the Presence of Alpha or Beta Alumina
Made available in DSpace on 2014-12-12T00:32:33Z (GMT). No. of bitstreams: 1 7212389.pdf: 3485379 bytes, checksum: 804014b5fbde3bc6bc78a92f7007436c (MD5) Previous issue date: 1971
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Complexities of (U-Th)/he zircon thermochronology through the lens of zonation and deep time
Made available in DSpace on 2021-09-17T02:34:21Z (GMT). No. of bitstreams: 3 THURSTON-DISSERTATION-2021.pdf: 7628080 bytes, checksum: c6371e102e8d2076914a6d80ba36302b (MD5) LICENSE.txt: 4212 bytes, checksum: f34acdd052283bdcad4f0c41ed62f8d4 (MD5) PROQUEST_LICENSE.txt: 4558 bytes, checksum: …
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Characterizing Provenance of the Late Wisconsinan Rainy Lobe Using Fine-Fraction Geochemistry and Detrital Zircon Geochronology
… models, till matrix geochemistry, and detrital zircon geochronology. The multicomponent mixing model is developed to examine sedimentological variability by incorporation of older, underlying tills (e.g. Goldstein, 1989). The mixing model shows that the Hewitt till does not lie on the mixing …
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INNOVATIVE AND CONVENTIONAL APPROACHES TO DETRITAL ZIRCON PROVENANCE ANALYSIS: LOOKING TO THE PAST, PRESENT, AND FUTURE
… paleo, modern, and synthetic detrital datasets. Zircon is a common accessory mineral found in most detrital sediments, primarily due to its refractory nature. During formation, zircon preferentially incorporates the element U and Th into its crystal lattice while excluding Pb, making it ideal for …
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DETRITAL-ZIRCON GEOCHRONOLOGIC PROVENANCE ANALYSES THAT TEST AND EXPAND THE EAST SIBERIA - WEST LAURENTIA RODINIA RECONSTRUCTION
… test correlations, we determined detrital-zircon age spectra from samples from the Sette Daban Range of SE Siberia and the Death Valley and White-Inyo regions of SW Laurentia using SHRIMP and LAICPMS. Data indicate that several Siberian samples contain zircons correlative with Laurentian …
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DETRITAL-ZIRCON GEOCHRONOLOGIC PROVENANCE ANALYSES THAT TEST AND EXPAND THE EAST SIBERIA - WEST LAURENTIA RODINIA RECONSTRUCTION
… test correlations, we determined detrital-zircon age spectra from samples from the Sette Daban Range of SE Siberia and the Death Valley and White-Inyo regions of SW Laurentia using SHRIMP and LAICPMS. Data indicate that several Siberian samples contain zircons correlative with Laurentian …
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Provenance and Tectonic Implications of LA-ICP-MS Zircon Depth-Profiling, Nanaimo Basin, British Columbia, Canada
Detrital zircon studies from sedimentary rocks of the Nanaimo Basin provide an important independent test of the Late Cretaceous paleogeographic position for the basin, and the associated Insular Superterrane, Coast Plutonic Complex (CPC), and North Cascades of the North American Cordillera. …
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Paleogeography of Western North America: Insights from Detrital Zircon U-Pb Geochronology and Hf Isotope Geochemistry
… and Hf isotope geochemistry of detrital zircons, as well as, geologic mapping and paleocurrent analysis. The Neoproterozoic through Pennsylvanian Yukon-Tanana terrane (YTTs) in the Coast Mountains of southeastern Alaska, the Cretaceous through Eocene strata in the San Juan basin of …
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Detrital zircon geochronology of the Upper Miocene Boleo Formation in the Santa Rosalia, Baja California Sur, Mexico
… constrained. We carried out a U-Pb detrital zircon study of the Boleo Formation to constrain its maximum depositional age. The Boleo Formation has basal limestone and gypsum sections that may be time transgressive. These are overlain by a much thicker clastic sequence, with coarsening upward …
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An investigation into the fluorination capabilities of ammonium acid fluoride under microwave radiation with respect to zircon
South Africa is the second largest producer of zircon (ZrSiO4) in the world, Australia being the largest. Zircon is notorious for its chemical inertness. Extreme processing conditions such as alkaline fusion (NaOH at 600 °C or Na2CO3 at 1200 °C) are used to extract the zirconium values from the …
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Magmatic evolution of the southern Centinela district, northern Chile: insights from PGE geochemistry and zircon fertility tools
… whole-rock geochemistry (including the PGE) and zircon geochronology of the Polo Sur and Penacho Blanco porphyry copper deposits of the southern Centinela District, northern Chile. This project aims to test the hypothesis that the timing of sulfide saturation, relative to volatile exsolution, is …
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