This data set contains U-Pb isotopic data and ages, Hf isotope data, and trace element concentrations of zircon from igneous rocks collected from the Yukon-Tanana Upland, eastern Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2013 to 2019. …Web
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The Gacun deposit is a typical Volcanic Hosted Massive Sulfide (VHMS) associated with Late Triassic seafloor calc-alkaline felsic volcanics. Studies of zircon ages, petrology, major and trace element geochemistry, and Sr-Nd-Hf isotope geochemistry of volcanic rocks from the Northern Yidun arc were undertaken in this paper. We reshaped …Web
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1. Introduction. The isotope 176 Lu decays by ß − emission to 176 Hf with a half-life of ~ 37 Gyr (McNair, 1961).The potential application of the Lu–Hf radioactive decay system to geochronology was first indicated by Boudin and Deutsch (1970). Patchett and Tatsumoto, 1980a, Patchett and Tatsumoto, 1980b, Patchett and Tatsumoto, 1980c …Web
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The Lu-Hf isotope systematic is extensively used in Earth sciences for geochronological and geochemical investigations. In metamorphic rocks containing garnet, the Lu-Hf systematic is a powerful dating tool to constrain metamorphic ages, especially in eclogites (e.g., Skora et al. 2006; Smit et al. 2010; Estrada-Carmona et al. …Web
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The radiogenic isotope applications of the Lu-Hf system utilize variations in 176 Hf resulting from the radioactive decay of 176 Lu to 176 Hf and variations in the Lu/Hf ratios in rocks and minerals. It is used both in geochronology, primarily in rocks containing a high Lu/Hf phase, and in tracer isotopic applications, to track the chemical evolution of …Web
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hafnium isotopes U-Pb geochronology mantle-crust interaction thermal modelling continental crust 1. Introduction Heat and mass input into the continental crust …Web
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In such cases the hafnium isotopic composition of the melt was probably strongly influenced by the dissolved zircon component at the source. ... Pankhurst RJ (1994) Geochronology and radiogenic isotope geology of Mesozoic rocks from eastern Palmer Land, Antarctic Peninsula; crustal anatexis in arc-related granitoid genesis. J South Am …Web
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U–Pb geochronology of baddeleyite (ZrO 2) is an increasingly used tool in the Earth and planetary sciences for determining the crystallization and emplacement ages of mafic igneous rocks.Additionally, baddeleyite has a strong affinity for hafnium and preferentially excludes the REE's, making it an important repository of Hf isotopic …Web
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Hafnium isotope data for the Simuku Igneous Complex, New Britain, Papua New Guinea. Hafnium isotope data related to "Melanesian arc far-field response to collision of the Ontong Java Plateau: geochronology and petrogenesis of the Simuku Igneous Complex, New Britain, Papua New Guinea". Understanding the evolution of the mid …Web
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Geochronology involves understanding time in relation to geological events and processes. Geochronological investigations examine rocks, minerals, fossils and sediments. Absolute and relative dating approaches complement each other. Absolute age determination is performed by radiogenic isotope dating methods such as U- (Th)-Pb, U-series, K-Ar ...Web
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We introduce a potential new working reference material – natural zircon megacrysts from an Early Pliocene alkaline basalt (from Penglai, northern Hainan Island, southern China) – for the microbeam determination of O and Hf isotopes, and U–Pb age dating. The Penglai zircon megacrysts were found to be fairly homogeneous in Hf and O …Web
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Introduction. Hafnium consists of the five stable isotopes 176 Hf, 177 Hf, 178 Hf, 179 Hf, and 180 Hf. Of these, ~1% of 176 Hf is radiogenic (the rest being "common" …Web
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We applied U-Pb geochronology, trace-element, and Hf isotope analyses of zircon from the Miocene Himalayan granites to address this issue. Autocrystic zircon had εHf values (at 20 Ma) of –12.0 ...Web
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Chapter 3: A hafnium isotopic record of magmatic arcs and continental growth in the Iapetus Ocean: the contrasting evolution of Ganderia and the peri-Laurentian margin Abstract 119 Introduction 119 Geological framework 120 Sample selection 125 Analytical methods 126 Results: zircon geochronology 128 Results: hafnium isotopes 133Web
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Our data show pronounced differences in the hafnium isotope–time patterns across this interval, requiring changes in the characteristics of the magmatic …Web
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Geochemical segmentation of the Mid-Atlantic Ridge north of Iceland and ridge–hot spot interaction in the North Atlantic. Geochem. Geophys. Geosys. 6 ( 1 ), 1 – 27. CrossRef Google Scholar. Blichert-Toft, J. and Albarede, F. ( 1997 ). The Lu–Hf isotope geochemistry of chondrites and the evolution of the mantle–crust system.Web
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We also specialize in garnet Lu-Hf and Sm-Nd geochronology. We are able to perform all this work in the Radiogenic Isotope and Geochronology Laboratory ... J.D. and Patchett, P.J., 1996, Behavior of hafnium and neodymium isotopes in the crust: constraints from Precambrian crustally derived granites. Geochimica et Cosmochimica Acta, v. 60, p ...Web
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Hafnium isotope compositions are used to determine the geochemical character of the magma in which the zircons crystallized. When combined with U-Pb …Web
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We propose that this secular shift in the global hafnium isotope record reflects a gradual yet widespread transition from stagnant-lid to mobile-lid tectonics on the early Earth. Figures and …Web
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To better characterize the origin of the province, and especially the sources and the relative roles of juvenile and recycled crustal components in crust formation, we measured Hf isotopic compositions of zircons analyzed for U-Pb geochronology by conventional means and by ion microprobe (Wooden and Miller, 1990; Wooden et al., …Web
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In-situ hafnium isotope ratio analysis of zircon by inductively coupled plasma multiple collector mass spectrometry. Chem. Geol. (1995) ... According to field relationships, petrology, geochronology, and geochemistry, the granitoid types can be divided into three groups: (1) ...Web
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The Pb, Nd, and Hf fractions were converted to nitrate prior to isotopic analyses by multi-collector inductively coupled plasma mass spectrometry. The feasibility of this new procedure is confirmed by the analyses of four international rock standards (BCR-2, AGV-2, BHVO-2, and JB-3), which yielded isotope ratios that were in good agreement …Web
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Hafnium isotopes trace the interaction of mantle-derived magmas with the surrounding continental crust during assembly of the lower crustal magmatic roots and subsequent ascent through the crust. ... Metrology and traceability of U–Pb isotope dilution geochronology (EARTHTIME Tracer Calibration Part I) Geochim. Cosmochim. Acta, …Web
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The Lu-Hf isotopic system is based on the beta decay of 176 Lu to 176 Hf, with a half-life of about 37 billion years (Söderlund et al. 2004). Lutetium and Hf are fractionated differently during ...Web
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In situ U‐Pb geochronology and hafnium, oxygen and zirconium isotope measurements in zircons using laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) and ion ...Web
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U-Pb ages and Hf isotope data for Roberts Mountains allochthon strata. U-Pb dates were run for all sample grains; approximately one-fourth of these grains were analyzed for hafnium isotopes. The upper graph shows εHf (t) (epsilon Hf) values for each sample. The average measurement uncertainty for all hafnium analyses is shown in the upper ...Web
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Abstract In this study, zircon grains are applied for U–Pb dating, Hf isotopes and trace elements to reveal the origin of magmatism and tectonic evolution of Late Paleozoic rocks of the Indian plate, Northern Pakistan.Web
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8.1 Isotopes in Geochronology. Some 176 Hf is radiogenic as a result of it being formed as a product of beta decay of radioactive 176 Lu (half-life of 3.73×10 10 years) [301]. ... Hafnium isotopic compositions of terrestrial materials evolved differently depending on the relative rates of 176 Hf production.Web
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exploration datasets. The Zircon lutetium–hafnium isotope map digital data are also available as a free download from the Data and Software Centre via Datasets — Statewide spatial datasets — Geochronology & Isotope Geology — Zircon lutetium-hafnium isotope map, as ESRI shapefiles and MapInfo TAB files.Web
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U-Pb geochronology. U-Pb isotopic data for new zircon analyses are provided in Table 1. Different eruption age interpretations of volcaniclastics as well as emplacement and crystallization age interpretations for intrusions are given in Table 2. ... Hafnium isotopes trace the interaction of mantle-derived magmas with the surrounding …Web
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R. Damian Nance, in Encyclopedia of Geology (Second Edition), 2021. Ratio of the hafnium isotopes 176 Hf/ 177 Hf in a sample expressed as a deviation from the same ratio in the …Web
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Insights from zircon U-Pb geochronology and hafnium isotopic composition of the Red Bluff Granite Suite, west Texas, USA: Geosphere, v. 19, no. 2, p. 599–627, tps://ht doi /10.1130 /GES02577.1 . Science Editor: Christopher J. Spencer Published online 1 February 2023 Received 25 July 2022 Revision received 17 October 2022 Accepted 13 ...Web
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In situ U‐Pb geochronology and hafnium, oxygen and zirconium isotope measurements in zircons using laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) and ion ...Web
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Lutetium-hafnium ages that are based on the previously used λ 176 Lu of 1.93 × 10 −11 to 1.94 × 10 −11 year −1 are thus ∼4% too young, and the initial hafnium isotope compositions of some of Earth's oldest minerals and rocks become less radiogenic relative to bulk undifferentiated Earth when calculated using the new decay constant.Web
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In situ U‐Pb geochronology and hafnium, oxygen and zirconium isotope measurements in zircons using laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) and ion ...Web
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In this article, we document a detailed analytical characterisation of zircon M127, a homogeneous 12.7 carat gemstone from Ratnapura, Sri Lanka. Zircon M127 has TIMS-determined mean U–Pb radiogenic isotopic ratios of 0.084743 ± 0.000027 for 206 Pb/ 238 U and 0.67676 ± 0.00023 for 207 Pb/ 235 U (weighted means, 2s uncertainties).Web
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