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Showing 1 to 20 of 26 for “"detrital zircons"”.
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Archean detrital zircons in the Proterozoic Vishnu Schist of the Grand Canyon, Arizona : implications for crustal architecture and Nuna reconstructions
U-Pb dating of 1035 detrital zircons from twelve spatially-distributed samples of the Paleoproterozoic Vishnu Schist reveals a bimodal 207Pb/ 206Pb age probability diagram with peaks at 1.8 Ga and 2.5 Ga. Surprisingly, only 13% of detrital zircon ages overlap with the published depositional age …
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RECONSTRUCTING PAST ANTARCTIC ICE FLOW PATHS IN THE ROSS EMBAYMENT, ANTARCTICA USING SAND PETROGRAPHY, PARTICLE SIZE AND DETRITAL ZIRCON PROVENANCE
… Ross Sea. Particle size, sand petrography, and detrital zircons were used to provide new information on the subglacial geology of Antarctica, as well as assisting in the reconstruction of Last Glacial Maximum (LGM) ice flow paths. Statistical analyses using the Kolmogorov-Smirnov (K-S test) …
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Paleogeography of Western North America: Insights from Detrital Zircon U-Pb Geochronology and Hf Isotope Geochemistry
… geochronology 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 …
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Miocene core complex development and coeval supradetachment basin evolution of Paros, Greece
… and improbable results in the footwall suite of zircons are examined using laser ablation depth-profiling to address the inherent assumption of homogeneous parent nuclide distribution in the zircon (U-Th)/He technique. Results from footwall zircon (U-Th)/He analyses indicate rapid cooling in …
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Tertiary Sediments of the Big Hole Valley and Pioneer Mountains, Southwestern Montana: Age, Provenance, and Tectonic Implications
… and rare fluvial deposits. U-Pb geochronology of detrital zircons and air-fall tuffs indicates the presence of Oligocene to Middle Miocene sedimentary rocks outcropping at the surface. Though the presence of detrital muscovite in several outcrops indicates derivation from the nearby 2-mica Chief …
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Tertiary Sediments of the Big Hole Valley and Pioneer Mountains, Southwestern Montana: Age, Provenance, and Tectonic Implications
… and rare fluvial deposits. U-Pb geochronology of detrital zircons and air-fall tuffs indicates the presence of Oligocene to Middle Miocene sedimentary rocks outcropping at the surface. Though the presence of detrital muscovite in several outcrops indicates derivation from the nearby 2-mica Chief …
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Detrital Zircon Analysis of Permian Victoria Group Sandstones, Transantarctic Mountains, Antarctica
… data indicate that this basin had two major detrital sources, a cratonic source and a volcaniclastic source that characterizes the upper Buckley Formation and younger Triassic beds. In order to investigate the sedimentary provenance further, detrital zircons have been examined from both …
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Palaeoenvironments and position of the Precambrian–Cambrian boundary within the lower Vanrhynsdorp Group of South Africa: sedimentary facies analysis, U-Pb series zircon geochronology and micropalaeontology
… the Vanrhynsdorp Group. Through U-Pb dating of detrital zircons using LA-ICP-MS, radiometric ages for the middle part of the Vanrhynsdorp Group (Besonderheid Formation) were obtained in a preliminary study of this project. The radiometric data, yielding a maximum depositional age of 524 to 528 …
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Zircon U-PB and LU-HF isotopic data from some peri-gondwana variscan terranes (Sardinia-Corsica block and calabropeloritan arc): new insights on the cenozoic geodynamic evolution of the central mediterranean basin
… detail, the geochemical data from magmatic and detrital zircons of the basement rocks highlight analogies or differences between the tectono-sedimentary sectors of the Sardinian Variscides (nappe and foreland zones) and between them and the Calabria Variscides. The geochemical whole rocks …
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Sedimentology, Stratigraphic Evolution and Provenance of the Cambrian – Lower Ordovician Potsdam Group in the Ottawa Embayment and Quebec Basin
… correlations, aided with provenance data from detrital zircons, show that changes in the areal distribution of sediment supply, accommodation and deposition/erosion were principally controlled by episodic reactivation of the Neoproterozoic Ottawa graben, which then periodically modified the …
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Syntectonic deposition and paleohydrology of the spring-fed Hualapai Limestone and implications for 5-6 MA integration of the Colorado River system through Grand Canyon : evidence from sedimentology, geochemistry and detrital zircon analysis
… includes new geochemistry, tephrochronology, and detrital zircon analysis to examine variations of the sedimentary and tectonic records from the Hualapai Limestone basins. Thickness variations, with progressively thicker deposits towards the east in two of the four basins, indicate syntectonic …
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Stable isotope paleohydrology of pedogenic carbonates in the Wayan Formation (Albian) from the wedge-top depozone in the North American Cretaceous Western Interior Basin
… from 6 well-developed paleosols were sampled for detrital zircons to determine maximum depositional ages. The first of these from the WF has produced a U-Pb concordia age of 101.0 ± 1.1 Ma, placing it in the uppermost Albian. This same WF section has produced a stratigraphic trend of upwardly …
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Provenance of the ice-cored moraine at Mt. Achernar, Law Glacier, Antarctica
… through time and space. Pebble lithology, detrital zircon geochronology, and till geochemistry were analyzed on samples from a 6.5 km transect. Hummocky topography occurs with the most recently exposed material along the active ice margin (Zone 1), followed by a relatively flat and low …
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Banda Forearc Metamorphic Rocks Accreted to the Australian Continental Margin: Detailed Analysis of the Lolotoi Complex of East Timor
… the approximate age of peak metamorphism. Detrital zircons from one amphibolite sample in East Timor yields a bimodal U-Pb age distribution of 560 Ma and 80 Ma, indicating deposition occurred after the 80 Ma closure of the zircon grains. The sequence of deformation as indicated by field …
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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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Oroclines of the Iberian Variscan belt: Tectonic and paleogeographic implications
… belt 2300 km in length. Provenance analysis of detrital zircons sampled from the Armorican Quartzite along a 1500-km-long segment of the palinplastically restored Iberian passive margin indicate that it originated in a paleogeographic position stretching east-west along the northern limits of …
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STRUCTURAL, THERMOCHRONOLOGICAL, AND STRATIGRAPHIC CONSTRAINTS ON THE EVOLUTION OF THE CLEARWATER METAMORPHIC CORE COMPLEX, IDAHO
… exhumation history of the CMCC. LA-ICPMS U-Pb detrital and igneous zircon geochronology in this study has confirmed the presence of pre-Belt quartzite, as well as 1870 ± 9 Ma basement orthogneiss in the CMCC. Detrital zircons in the quartzites show a dominant peak near ~1800 Ma, with smaller …
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STRUCTURAL, THERMOCHRONOLOGICAL, AND STRATIGRAPHIC CONSTRAINTS ON THE EVOLUTION OF THE CLEARWATER METAMORPHIC CORE COMPLEX, IDAHO
… exhumation history of the CMCC. LA-ICPMS U-Pb detrital and igneous zircon geochronology in this study has confirmed the presence of pre-Belt quartzite, as well as 1870 ± 9 Ma basement orthogneiss in the CMCC. Detrital zircons in the quartzites show a dominant peak near ~1800 Ma, with smaller …
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Sediment incorporation into continental arc systems and paleogeography of the western North American Cordillera: Insights from the North Cascades, Washington
… sedimentary-provenance information recorded in detrital-zircon U-Pb and Hf-isotope and whole-rock Nd-isotope analyses of (meta)sedimentary rocks from northwestern Washington and southern British Columbia, in conjunction with similar datasets from coeval (meta)sedimentary rocks to the south along …
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Triassic to Neogene Evolution of the Andean Retroarc: Neuquén Basin, Argentina
… This study presents new sedimentological and detrital zircon U-Pb data from the Jurassic to latest Cretaceous sedimentary strata to determine depositional environments, stratigraphic relations, provenance, and maximum depositional ages of these units and ultimately evaluate the role of …
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