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Автор: Grafiati

Опубліковано: 10 грудня 2022

Оновлено: 28 січня 2023

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1

Gudelius, Dominik, Sonja Aulbach, Hans-Michael Seitz, and Roberto Braga. "Crustal fluids cause strong Lu-Hf fractionation and Hf-Nd-Li isotopic provinciality in the mantle of continental subduction zones." Geology 50, no. 2 (November 2, 2021): 163–68. http://dx.doi.org/10.1130/g49317.1.

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Abstract Metasomatized mantle wedge peridotites exhumed within high-pressure terranes of continental collision zones provide unique insights into crust-mantle interaction and attendant mass transfer, which are critical to our understanding of terrestrial element cycles. Such peridotites occur in high-grade gneisses of the Ulten Zone in the European Alps and record metasomatism by crustal fluids at 330 Ma and high-pressure conditions (2.0 GPa, 850 °C) that caused a transition from coarse-grained, garnet-bearing to fine-grained, amphibole-rich rocks. We explored the effects of crustal fluids on canonically robust Lu-Hf peridotite isotope signatures in comparison with fluid-sensitive trace elements and Nd-Li isotopes. Notably, we found that a Lu-Hf pseudo-isochron is created by a decrease in bulk-rock 176Lu/177Hf from coarse- to fine-grained peridotite that is demonstrably caused by heavy rare earth element (HREE) loss during fluid-assisted, garnet-consuming, amphibole-forming reactions accompanied by enrichment in fluid-mobile elements and the addition of unradiogenic Nd. Despite close spatial relationships, some peridotite lenses record more intense fluid activity that causes complete garnet breakdown and high field strength element (HFSE) addition along with the addition of crust-derived unradiogenic Hf, as well as distinct chromatographic light REE (LREE) fractionation. We suggest that the observed geochemical and isotopic provinciality between peridotite lenses reflects different positions relative to the crustal fluid source at depth. This interpretation is supported by Li isotopes: inferred proximal peridotites show light δ7Li due to strong kinetic Li isotope fractionation (−4.7–2.0‰) that accompanies Li enrichment, whereas distal peridotites show Li contents and δ7Li similar to those of the depleted mantle (1.0–7.2‰). Thus, Earth's mantle can acquire significant Hf-Nd-Li-isotopic heterogeneity during locally variable ingress of crustal fluids in continental subduction zones.

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2

Johnson, Clark M., Steven B. Shirey, and Karin M. Barovich. "New approaches to crustal evolution studies and the origin of granitic rocks: what can the Lu-Hf and Re-Os isotope systems tell us?" Earth and Environmental Science Transactions of the Royal Society of Edinburgh 87, no. 1-2 (1996): 339–52. http://dx.doi.org/10.1017/s0263593300006738.

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ABSTRACT:The Lu-Hf and Re-Os isotope systems have been applied sparsely to elucidate the origin of granites, intracrustal processes and the evolution of the continental crust. The presence or absence of garnet as a residual phase during partial melting will strongly influence Lu/Hf partitioning, making the Lu–Hf isotope system exceptionally sensitive to evaluating the role of garnet during intracrustal differentiation processes. Mid-Proterozoic (1·1–1·5Ga ) ‘anorogenic’ granites from the western U.S.A. appear to have anomalously high εHf values, relative to their εNd values, compared with Precambrian orogenic granites from several continents. The Hf-Nd isotope variations for Precambrian orogenic granites are well explained by melting processes that are ultimately tied to garnet-bearing sources in the mantle or crust. Residual, garnet-bearing lower and middle crust will evolve to anomalously high εHf values over time and may be the most likely source for later ‘anorogenic’ magmas. When crustal and mantle rocks are viewed together in terms of Hf and Nd isotope compositions, a remarkable mass balance is apparent for at least the outer silicate earth where Precambrian orogenic continental crust is the balance to the high-εHf depleted mantle, and enriched lithospheric mantle is the balance to the low-εHf depleted mantle.Although the continental crust has been envisioned to have exceptionally high Re/Os ratios and very radiogenic Os isotope compositions, new data obtained on magnetite mineral separates suggest that some parts of the Precambrian continental crust are relatively Os-rich and non-radiogenic. It remains unclear how continental crust may obtain non-radiogenic Os isotope ratios, and these results have important implications for Re-Os isotope evolution models. In contrast, Phanerozoic batholiths and volcanic arcs that are built on young mafic lower crust may have exceptionally radiogenic Os isotope ratios. These results highlight the unique ability of Os isotopes to identify young mafic crustal components in orogenic magmas that are essentially undetectable using other isotope systems such as O, Sr, Nd and Pb.

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3

Huang, Chao, Yue-Heng Yang, Jin-Hui Yang, and Lie-Wen Xie. "In situ simultaneous measurement of Rb–Sr/Sm–Nd or Sm–Nd/Lu–Hf isotopes in natural minerals using laser ablation multi-collector ICP-MS." Journal of Analytical Atomic Spectrometry 30, no. 4 (2015): 994–1000. http://dx.doi.org/10.1039/c4ja00449c.

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This study presents a combined methodology of simultaneously measuring Rb–Sr/Sm–Nd or Sm–Nd/Lu–Hf isotopes in natural minerals by a means of two multiple collector inductively coupled plasma mass spectrometers connected to a 193 nm excimer laser ablation system.

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4

LIU, YU, KUNGUANG YANG, ALI POLAT, and XIAO MA. "Reconstruction of the Cryogenian palaeogeography in the Yangtze Domain: constraints from detrital age patterns." Geological Magazine 156, no. 07 (August 20, 2018): 1247–64. http://dx.doi.org/10.1017/s0016756818000535.

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AbstractDetrital zircons are often used to constrain the maximum sedimentary age of strata and sedimentary provenance. This study aimed at reconstructing the Cryogenian palaeogeography of the Yangtze Domain based on U–Pb ages and Lu–Hf isotopic signatures of detrital zircons from sandstones in the southeastern part of the Yangtze Domain. U–Pb ages of the youngest detrital zircon grains from the Niuguping, Gucheng and Datangpo formations yielded average ages of 712±24 Ma, 679.2±6.2 Ma and 665.1±7.4 Ma, respectively, which are close to the depositional ages of their respective formations. An integrated study of detrital zircon Lu–Hf isotopes and U–Pb ages from three samples revealed six main peak ages in the samples from the Anhua section atc. 680 Ma,c. 780 Ma,c. 820 Ma,c. 940 Ma,c. 2000 Ma andc. 2500 Ma. The characteristics of the U–Pb ages and Hf isotopes indicate a link between the north and southeast margins of the Yangtze Domain as early asc. 680 Ma, and the provenance of the coeval sedimentary sequences in the SE Yangtze Domain was the South Qinling Block on the northern margin of the Yangtze Domain. The provenance analysis on thec. 680 Ma detritus composing upper Neoproterozoic strata in the Yangtze Domain revealed that the detritus was transported southward from South Qinling to the southeast margin of the Yangtze Domain through the Exi Strait, but was hindered by the Jiangnan Orogenic Belt.

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5

Petersson, Andreas, Karolina Bjärnborg, Anders Scherstén, Axel Gerdes, and Tomas Næraa. "Tracing Proterozoic arc mantle Hf isotope depletion of southern Fennoscandia through coupled zircon U–Pb and Lu–Hf isotopes." Lithos 284-285 (July 2017): 122–31. http://dx.doi.org/10.1016/j.lithos.2017.04.010.

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6

Inácio Alves, Márcio, Bruna Saar de Almeida, Letícia Muniz da Costa Cardoso, Anderson Costa dos Santos, Ciro Appi, Anelise Losangela Bertotti, Farid Chemale, Armando Dias Tavares Jr, Maria Virginia Alves Martins, and Mauro César Geraldes. "ISOTOPIC COMPOSITION OF Lu, Hf AND Yb IN GJ-01, 91500 AND MUD TANK REFERENCE MATERIALS MEASURED BY LA-ICP-MS: APPLICATION OF THE Lu-Hf GEOCHRONOLOGY IN ZIRCON." Journal of Sedimentary Environments 4, no. 2 (June 23, 2019): 220–48. http://dx.doi.org/10.12957/jse.2019.43877.

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The Lu-Hf method has been used in the investigation of geological samples in order to understand processes and sources of magmatic rocks. This paper discusses the reference materials GJ-01, 91.500 and Mud Tank isotopic composition by LA-ICP-MS to investigate how suitable they are for the zircon analysis through this technique. The results show that the three zircons have homogeneous compositions for the proposed objectives. Considering that relatively high Yb contents produce isobaric interference, the results of this work have shown that the Mud Tank is the best reference material, since it has lower values of this element. Thus, the Mud Tank allows to obtain more reliable results due to lower correction requirements. In addition, it should be emphasized that the presented data corroborate the application of Hf isotopes for geological evolution and characterization of magmatic sources. The high abundances of Hf in the zircon grains allow to preserve the isotopic signatures of its crystallization from magmatic sources, allowing to characterize the isotopic signatures of the reservoir (s) that gave origin to that rocks, and in case studies of paleoclimate and paleoceanographic records and/or of sedimentary basins evolution, it allows to identify the origin of the sediments or temporal and spatial changes of the source of sedimentary particles. COMPOSIÇÃO ISOTÓPICA DE Lu, Hf e Yb ANALISADA POR LA-ICP-MS DOS MATERIAIS DE REFERÊNCIA “GJ-01”, “91.500” e “MUD TANK”: APLICAÇÃO DA GEOCRONOLOGIA Lu-Hf EM ZIRCÃO ResumoO método Lu-Hf tem sido utilizado para entender processos de formação e fontes de rochas magmáticas. Este artigo analisa a composição isotópica por LA-ICP-MS dos materiais de referência GJ-01, 91.500 e Mud Tank para investigar quão adequados eles são para a análise de zircônio através desta técnica. Os resultados mostram que os três zircões possuem composições homogêneas podendo ser usados com materiais de referência para as pesquizas referidas. Considerando que teores relativamente altos de Yb produzem interferência isobárica, os resultados deste trabalho mostraram que o Mud Tank é o melhor material de referência, uma vez que possui os menores valores deste elemento. O Mud Tank permite obter resultados mais confiáveis por requerer menor correção dos valores obtidos. Além disso, deve-se ressaltar que os dados apresentados corroboram a aplicação de isótopos de Hf para a evolução geológica e caracterização de fontes magmáticas. As altas abundâncias de Hf nos grãos de zircão permitem preservar as assinaturas isotópicas de sua cristalização a partir de fontes magmáticas, permitindo caracterizar as assinaturas isotópicas do (s) reservatório (s) que deram origem a essas rochas. Têm também utilidade em estudos de paleoclima e paleoceanográficos e/ou da evolução das bacias sedimentares, permitindo identificar a origem dos sedimentos ou mudanças temporais e espaciais da fonte das partículas sedimentares. Palavras-chave: Método Isotópico Lu-Hf. Interferência isobárica. Análise de Alta Resolução Espacial. Zircão. Calibração de materiais de georeferenciamento. Pesquisa analítica.

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7

Sakhno, V. G., and L. S. Tsurikova. "Isotopic and geochemical features of the genesis of igneous complexes and ore-magmatic systems in the Chukotka sector of the Russian Arctic coast." LITHOSPHERE (Russia) 20, no. 2 (April 25, 2020): 196–211. http://dx.doi.org/10.24930/1681-9004-2020-20-2-196-211.

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Research subject. The isotopic composition (Pb-Pb, Sm-Nd, Rb-Sr, Os/Os, Hf/Hf, 3 He/4 He, etc.) of magmatic complexes and ore-magmatic systems (OMS) of two ore clusters (Kupolsky and Ilirneysky) located in the subpolar Western Chukotka was studied. These ore clusters differ from each other both in their structural position and the age of their magmatic complexes, within which the largest deposits of Au-Ag type are known. Materials and methods. The Pb-Pb, Rb-Sr, SmNd, Re-Os, Lu-Hf, 3 He/4 He, 40Ar/36Ar and sulphur isotopic systems were studied at the VSEGEI centre for isotopic studies (St. Petersburg), as well as at the Institute of Geology, Geochemistry and Ore Deposits (IGEM, Moscow) and the Laboratory of Stable Isotopes of the Far Eastern Geological Institute (FEGI, Vladivostok). Re and Os were measured using an ELEMENT-2 inductively coupled plasma single-collector mass spectrometer. Sulphur isotopic ratios were measured using a Finnigan MAT 253 isotope mass spectrometer. Results and conclusions. On the basis of the isotope-geochemical data obtained, an assumption was made that various deep sources participated in the magma generation, and the differentiated composition of late melts may reflect the melting processes of the crust upper horizons. When comparing the data on the magmatism of the Ilirneysky and Kupolsky ore clusters, a different degree of crustal rock influence on melt generation was revealed. The Kupolsky ore cluster is characterised by a large influence of mantle sources in intraplate magmatism associated with ore formation processes. This is likely to have determined a greater amount of mineralisation in the Kupolsky cluster compared to the Ilirneysky ore cluster.

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8

Rasbury, E. Troy, and Jennifer M. Cole. "Directly Dating Sedimentary Rocks." Paleontological Society Papers 12 (October 2006): 77–105. http://dx.doi.org/10.1017/s1089332600001364.

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This contribution seeks to provide a summary of radiometric dating techniques that are currently applicable to Phanerozoic sedimentary deposits and therefore relevant to paleontologists. First we overview the assumptions necessary for radiometric dating and introduce isochrons and concordia diagrams as methods for calculating ages and evaluating isotope systematics. We then focus on the four most promising systems: U-Pb dating of carbonates, Re-Os dating of black shales, and U-Pb and Lu-Hf dating of phosphates. We review expected geochemical behavior of daughter and parent isotopes in the context of both marine and terrestrial depositional environments. A critical evaluation of previously published ages and potential directions for future work are provided.

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9

Attia, Snir, John M. Cottle, and Scott R. Paterson. "Erupted zircon record of continental crust formation during mantle driven arc flare-ups." Geology 48, no. 5 (February 14, 2020): 446–51. http://dx.doi.org/10.1130/g46991.1.

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Abstract Coupled zircon U-Pb age, trace-element, and Lu-Hf isotope analyses from central Sierra Nevada (eastern California, USA) metavolcanic strata reveal the expression of three Mesozoic arc flare-ups in the volcanic record over ∼150 m.y. of magmatic activity. Zircon εHf(i) values vary up to 20 epsilon units within individual samples and coeval sample populations but show no clear links with other geochemical indices, requiring both mixing and fractionation for arc magma genesis. Zircon compositions show repeated temporal trends across flare-ups: Hf isotopes spanning evolved to juvenile values converge to more juvenile compositions, middle rare earth element (MREE) depletion and heavy REE slopes increase during flare-up main phases, and highly variable U/Yb values converge to low values as flare-ups conclude. Despite pervasive contamination, juvenile source magmas dominate magmas erupted throughout the entirety of high-magma-addition episodes. Arc flare-ups thus represent ∼30 m.y. of increased mantle magma input that represents significant continental crust formation in Cordilleran arcs.

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10

LAMMINEN, JARKKO, TOM ANDERSEN, and JOHAN PETTER NYSTUEN. "Provenance and rift basin architecture of the Neoproterozoic Hedmark Basin, South Norway inferred from U–Pb ages and Lu–Hf isotopes of conglomerate clasts and detrital zircons." Geological Magazine 152, no. 1 (May 2, 2014): 80–105. http://dx.doi.org/10.1017/s0016756814000144.

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AbstractThe Neoproterozoic Hedmark Basin in the Caledonides of South Norway was formed at the western margin of the continent Baltica by rifting 750–600 Ma ago. The margin was destroyed in the Caledonian Orogeny and sedimentary basins translated eastwards. This study uses provenance analysis to map the crustal architecture of the pre-Caledonian SW Baltican margin. Conglomerate clasts and sandstones were sampled from submarine fan, alluvial fan and terrestrial glacigenic sedimentary rocks. Samples were analysed for U–Pb isotopes and clast samples additionally for Lu–Hf isotopes. The clasts are mainly granitesc. 960 Ma and 1680 Ma old, coeval with the Sveconorwegian Orogeny and formation of the Palaeoproterozoic Transscandinavian Igneous Belt (TIB). Mesoproterozoic (Sveconorwegian) ages are abundant in the western part of the basin, whereas Palaeoproterozoic ages are common in the east. Lu–Hf isotopes support crustally contaminated source for all clasts linking them to Fennoscandia. Detrital zircon ages of the sandstones can be matched with those from the granitic clasts except for ages within the range 1200–1500 Ma. These ages are typically found in the present-day Telemark, SW Norway. The sandstones and conglomerate clasts in the western part of the Hedmark Basin were sourced from the Sveconorwegian domain in the present SW Norway or its continuation to the present-day NW. The conglomerate clasts in the eastern part of the Hedmark Basin were sourced mainly from the TIB domain or its northwesterly continuation. The Hedmark Basin was initiated within the boundary of two domains in the basement: the TIB and the Sveconorwegian domains.

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11

Martin, Erin L., William J. Collins, and Christopher J. Spencer. "Laurentian origin of the Cuyania suspect terrane, western Argentina, confirmed by Hf isotopes in zircon." GSA Bulletin 132, no. 1-2 (June 12, 2019): 273–90. http://dx.doi.org/10.1130/b35150.1.

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Abstract The proto-Andean margin of Argentina consists of several suspect terranes, the origins of which are disputed. The Cuyania (greater Precordillera) suspect terrane was originally interpreted to be of southeast Laurentian affinity, but more recently a southwestern Gondwanan provenance has been argued. Both potential source regions comprise Mesoproterozoic rocks, but we show they are isotopically distinct, using previously published zircon Lu-Hf data. Detrital zircon εHf data from southwestern Gondwana (Namaqua-Natal belt) show no correlation with new zircon U-Pb and Lu-Hf data from Cuyania, suggesting that Gondwana was not the source of these sediments. Rather, detrital zircons from Cambrian strata in Cuyania yield Mesoproterozoic zircons with depleted εHf that correlate to the Grenville margin of Laurentia, and a ca. 535 Ma zircon population sourced directly from rift-related rocks of the Ouachita Embayment, thus recording rifting and drifting of Cuyania from Laurentia. By contrast, zircons from Middle to Late Ordovician strata of Cuyania record a larger range of εHf values, correlated with Western Sierras Pampeanas Mesoproterozoic basement inliers of Argentina. These synorogenic clastic deposits record the Ordovician arrival of Cuyania at the proto-Andean margin of Gondwana. The new data require the terrane boundaries of Cuyania to be redefined, thereby excluding Western Sierras Pampeanas basement inliers. The results verify the Laurentian microcontinent model for the origin of Cuyania.

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12

Payne, Justin L., David J. McInerney, Karin M. Barovich, Christopher L. Kirkland, Norman J. Pearson, and Martin Hand. "Strengths and limitations of zircon Lu-Hf and O isotopes in modelling crustal growth." Lithos 248-251 (April 2016): 175–92. http://dx.doi.org/10.1016/j.lithos.2015.12.015.

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13

Vlach, Silvio R. F. "On the Morphology and Geochemistry of Hydrothermal Crypto- and Microcrystalline Zircon Aggregates in a Peralkaline Granite." Minerals 12, no. 5 (May 14, 2022): 628. http://dx.doi.org/10.3390/min12050628.

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Singular crypto- and microcrystalline hydrothermal zircon aggregates occur in peralkaline granites from the Corupá Pluton of “A-type” granites and syenites in Graciosa Province, Southern Brazil, and are herein characterized for their morphological, textural and geochemical (major, minor and trace elements, and Lu-Hf isotopes) properties. The aggregates were found to present a variety of habits, such as dendritic, oolitic, botryoidal and spherulitic, and they are associated with typical hydrothermal minerals (alkali-feldspars, quartz, fluorite, epidote-group minerals, phyllosilicates and Fe oxides) in micro-fractures and small miarolitic cavities in the host rock. They precipitated directly from a hydrothermal fluid and, compared to magmatic zircon crystals from the host, were found to contain relatively high abundances of the “non-formula” elements (e.g., Fe, Al, and Ca) and HFSEs (High-Field-Strength Elements), particularly the L- and MREEs (Light and Medium Rare Earth Elements), features most typical of hydrothermal zircon, as well as high Th/U ratios, whereas the Lu-Hf isotopic signatures were found to be similar. The formation of the zircon aggregates and the associated epidote-groups minerals was probably due to the interaction between an orthomagmatic, F-bearing, aqueous fluid transporting the HFSEs with the host-rock and/or with an external meteoritic fluid from the country rocks. The preservation of an amorphous-like Zr-silicate compound and crypto-to-microcrystalline zircon varieties is arguably related to the inefficient fluid flux and/or elemental diffusion in a low-temperature oxidizing environment.

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14

Cheong, Albert Chang-sik, Youn-Joong Jeong, Shinae Lee, Keewook Yi, Hui Je Jo, Ho-Sun Lee, Changkun Park, Nak Kyu Kim, Xian-Hua Li, and Sandra L. Kamo. "LKZ-1: A New Zircon Working Standard for the In Situ Determination of U–Pb Age, O–Hf Isotopes, and Trace Element Composition." Minerals 9, no. 5 (May 27, 2019): 325. http://dx.doi.org/10.3390/min9050325.

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This study introduces a new zircon reference material, LKZ-1, for the in situ U–Pb dating and O–Hf isotopic and trace element analyses. The secondary ion mass spectrometric analyses for this gem-quality single-crystal zircon yielded a weighted mean 206Pb/238U age of 572.6 ± 2.0 Ma (2σ, n = 22, MSWD = 0.90), with moderately high U concentrations (619 ± 21 ppm, 1 SD), restricted Th/U ratios (0.146 ± 0.002, 1 SD), and negligible common Pb content (206Pbc < 0.2%). A comparable 206Pb/238U age (570.0 ± 2.5 Ma, 2σ) was produced by the isotope dilution-thermal ionization mass spectrometry. The secondary ion mass spectrometric and laser ablation-assisted multiple collector inductively coupled plasma mass spectrometer analyses respectively showed that LKZ-1 had little variation in O (δ18OV-SMOW = 10.65 ± 0.14‰; laser fluorination value = 10.72 ± 0.02‰; 1 SD) and Hf (176Hf/177Hf = 0.281794 ± 0.000016, 1 SD) isotopic compositions. LKZ-1 was also fairly homogeneous in its chemical composition (RSD of laser ablation ICPMS data ≤ 10%), displaying a relatively uniform chondrite-normalized rare earth element pattern ((Lu/Gd)N = 31 ± 3, Eu/Eu* = 0.43 ± 0.17, Ce/Ce* = 44 ± 32; 1 SD). These consistencies suggest that the LKZ-1 zircon is a suitable working standard for geochronological and geochemical analyses.

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15

Zeng, Renyu, Jianqing Lai, Xiancheng Mao, Bin Li, Jiandong Zhang, Richard BAYLESS, and Lizhi Yang. "Paleoproterozoic Multiple Tectonothermal Events in the Longshoushan Area, Western North China Craton and Their Geological Implication: Evidence from Geochemistry, Zircon U–Pb Geochronology and Hf Isotopes." Minerals 8, no. 9 (August 21, 2018): 361. http://dx.doi.org/10.3390/min8090361.

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The Alxa block is located in the southwestern margin of the North China Craton. The Paleoproterozoic tectonic evolution, crustal growth and tectonic affinity of the block remain unknown or controversial. The Longshoushan (LS) area is one of the few areas that outcrop Paleoproterozoic to crystalline basement rocks in the Alxa Block. In this study, we preset whole-rock geochemistry, zircon U–Pb geochronology and Lu–Hf isotope data from metagabbro, metadiorite, quartz syenite, granitic leucosome and pegmatoid leucosome in the LS area. These rocks all are enriched in LREE and LILE, and depleted in HREE and HFSE. Eight new LA-ICP-MS zircon U–Pb ages yielded three magmatic ages of 2044 Ma, 2029 Ma and 1940 Ma, and three metamorphic ages of 1891 Ma, 1848 Ma and 1812 Ma. Lu–Hf analyses reveal that the magmatic zircons and anatectic/metamorphic zircons from all the rock types are characterized by positive εHf(t) (−0.16 to 10.89) and variable εHf(t) (−11.21 to 6.24), respectively. Based on the previous studies and our new data, we conclude that the LS area experienced three magmatic events (2.5–2.45 Ga, ~2.1–2.0 Ga and ~1.95–1.91 Ga) and three regional metamorphism/anataxis events (~1.93–1.89 Ga, ~1.86–1.84 Ga and ~1.81 Ga) in Paleoproterozoic. The age–Hf isotope data establishes two main crustal growth events at ~2.9–2.5 Ga and ~2.2–2.0 Ga in the LS area. These data indicate that the LS area experienced intraplate extensional setting in the middle Paleoproterozoic, and continental subduction, collision and exhumation in the late Paleoproterozoic. Combining the geochronological framework and tectonic evolution, we suggest that the Alxa Block is part of the Khondalite Belt.

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16

Zhu, Mingtian, Lianchang Zhang, Yanpei Dai, Changle Wang, and Zidong Peng. "Hydrothermal modification of zircon geochemistry and Lu–Hf isotopes from the Hongtoushan Cu–Zn deposit, China." Ore Geology Reviews 86 (June 2017): 707–18. http://dx.doi.org/10.1016/j.oregeorev.2017.03.028.

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17

Bikramaditya, R. K., A. Krishnakanta Singh, Sun-Lin Chung, Rajesh Sharma, and Hao-Yang Lee. "Zircon U–Pb ages and Lu–Hf isotopes of metagranitoids from the Subansiri region, Eastern Himalaya: implications for crustal evolution along the northern Indian passive margin in the early Paleozoic." Geological Society, London, Special Publications 481, no. 1 (November 22, 2018): 299–318. http://dx.doi.org/10.1144/sp481.7.

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AbstractWe studied the zircon U–Pb ages, Hf isotopes, and whole-rock and mineral chemistry of metagranitoids from the Subansiri region of the Eastern Himalaya to constrain their emplacement age, origin and geodynamic evolution. The investigated metagranitoids have high SiO2, Na2O + K2O, Rb, Zr and low Fe2O3, Nb, Ga/Al ratios with fractionated rare earth element patterns [(Ce/Yb)N = 6.46–42.15] and strong negative Eu anomalies (Eu/Eu* = 0.16–0.44). They are peraluminous (molar A/CNK = 1.04–1.27) and calc-alkaline in nature, with normative corundum (1.04–3.61) and relatively high FeOt/MgO ratios in biotite (c. 3.38), indicating their affinity with S-type granites. The time of emplacement of the Subansiri metagranitoids is constrained by zircon U–Pb ages between 516 and 486 Ma. The zircon grains have negative εHf(t) values ranging from −1.4 to −12.7 and yield crustal Hf model ages from 1.5 to 2.2 Ga, suggesting the occurrence of a major crustal growth event in the Proterozoic and re-melting of the crust during the early Paleozoic. The geochemical data in conjunction with the U–Pb ages and Hf isotope data suggest that the Subansiri metagranitoids were produced by partial melting of older metasedimentary rocks in the Indian passive margin.Supplementary material: Hf isotope results for the Mud Tank zircon standard acquired during the experimental period are available at https://doi.org/10.6084/m9.figshare.c.4299830

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Wei, Pengfei, Xuefeng Yu, Dapeng Li, Qiang Liu, Lidong Yu, Zengsheng Li, Ke Geng, Yan Zhang, Yuqin Sun, and Naijie Chi. "Geochemistry, Zircon U–Pb Geochronology, and Lu–Hf Isotopes of the Chishan Alkaline Complex, Western Shandong, China." Minerals 9, no. 5 (May 13, 2019): 293. http://dx.doi.org/10.3390/min9050293.

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Mass alkaline magmatic activities in Western Shandong during the late Mesozoic controlled the mineralization processes of gold and rare earth element (REE) polymetallic deposits in the region. The Chishan alkaline complex is closely associated with the mineralization of the Chishan REE deposit, which, as the third largest light REE deposit in China following the Baiyenebo (Inner Mongolia) and Mianning (Sichuan) deposits, is considered a typical example of alkaline rock mineralization throughout the North China Craton. To determine how the Chishan alkaline complex and REE deposit interact with each other, a systematic study was conducted on the petrology, rock geochemistry, zircon U–Pb geochronology, Lu–Hf isotopes of the quartz syenite, and alkali granite contained in the Chishan alkaline complex. The results reveal that the deposits feature similar geochemical characteristics typical of an alkaline rock series—both are rich in alkali, high in potassium, metaluminous, and poor in Ti, Fe, Mg, and Mn. In terms of REEs, the deposits are strongly rich in light REEs but poor in heavy REEs, with weak negative Eu anomalies. In terms of trace elements, they are rich in large ion lithophile elements Ba, Sr, and Rb but poor in high field-strength elements Nb, Ta, and Hf. Zircon LA-ICP-MS U–Pb dating indicated that the quartz syenite and alkali granite formed in Early Cretaceous at 125.8 ± 1.2 Ma and 127.3 ± 1.0 Ma, respectively; their εHf(t) values are −22.67 to −13.19, with depleted model ages (TDM) ranging from 1296 Ma to 1675 Ma and crustal model ages (TDMC) of 2036–2617 Ma. The Chishan alkaline complex originated from partial of the EM I-type (enriched mantle I) lithospheric mantle with assimilation of ancient crustal materials. The complex is of the same origin as the REE deposit, and developed in an extensional setting that resulted from plate subduction and lithospheric thinning and upwelling in the eastern area of the North China Craton.

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Xie, LieWen, YanBin Zhang, HuiHuang Zhang, JingFeng Sun, and FuYuan Wu. "In situ simultaneous determination of trace elements, U-Pb and Lu-Hf isotopes in zircon and baddeleyite." Science Bulletin 53, no. 10 (May 2008): 1565–73. http://dx.doi.org/10.1007/s11434-008-0086-y.

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SHARDAKOV, Galina Yur’evna, and Mariya Vladimirovna CHERVYAKOVSKAYA. "Vendian-Cambrian granites of the Ufaley block (Middle Urals): a new isotope data, source composition, potential ore content." NEWS of the Ural State Mining University 1, no. 2 (June 15, 2020): 48–63. http://dx.doi.org/10.21440/2307-2091-2020-2-48-63.

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Relevance. The junction zone between the Uralian mobile belt (UMB) and the East European Platform (EEP) is long, heterogeneous and characterized by asynchrony in the geodynamic settings. For many of its constituent parts, the age, source composition and ore content of magmatic complexes, which are necessary to build a complete picture of geological history, are not completely clear. The aim of this work is to study petrogeochemistry, age, isotopic parameters, and reconstruction of the source composition for granites of the Bitim complex in the eastern part of the Ufaley block (Middle Urals). This structure is considered to be a fragment displaced from the EEP to the east. Research methodology. The analysis of rocks for petrogenic and rare components, microprobe studies of the composition of minerals and isotope studies of U–Pb, Lu–Hf (LA–ICP–MS) were performed. Petrocheochemical comparison was made, author’s data about Ar–Ar, Rb–Sr age and the behavior of Sr and Hf isotopes were analyzed. Results. Granitoids of the Bitim complex formed over a long time interval – 579–520 Ma, corresponding to the Upper Vendian (taking into account errors – to the boundary with the Cambrian). The isotopic labels of the studied granites are as follows: 87Sr/86Sr = 0.703389, εHf (t) is +1.5...+12.5, 176Hf/177Hf = 0.28253–0.282797. Conclusions. The geodynamics of the Vendian stage is the activation of movements along previously existing riftogenic faults. Deep source of magma generation for granites was heterogeneous: the mantle played a significant role, the crustal component was represented by ancient graywacks. U–Pb dating of zircons transformed as a result of the post-Cambrian tectonothermal activity is comparable with the ages of the main geodynamic events in UMM (spreading, subduction, collision). The behavior of F, Cl, S in apatites, which is an indicator of the fluid regime, shows that gold mineralization of the quartz-vein type can be associated with the Bitim granites. Studies are clarified the imagination about the structure of the junction zone between UMM and EEP and can be used in geological and metallogenic mapping.

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GUO, Xianqing, Zhen YAN, Jonathan C. AITCHISON, Changlei FU, and Zongqi WANG. "Geochemistry, Geochronology and Lu-Hf Isotopes of Peraluminous Granitic Porphyry from the Walegen Au Deposit, West Qinling Terrane." Acta Geologica Sinica - English Edition 91, no. 6 (December 2017): 2024–40. http://dx.doi.org/10.1111/1755-6724.13448.

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Wang, Ruirui, Zhiqin Xu, M. Santosh, Yuan Yao, Li'e Gao, and Chunhua Liu. "Late Neoproterozoic magmatism in South Qinling, Central China: Geochemistry, zircon U-Pb-Lu-Hf isotopes and tectonic implications." Tectonophysics 683 (June 2016): 43–61. http://dx.doi.org/10.1016/j.tecto.2016.05.050.

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23

Shardakova, G. Yu, and A. V. Korovko. "Vendian-Cambrian granites of the Salatim suture zone (the Northern Urals): Geochemistry of zircons, source composition, geochronological and geodynamical consequences." LITHOSPHERE (Russia) 21, no. 1 (March 4, 2021): 32–54. http://dx.doi.org/10.24930/1681-9004-2021-21-1-32-54.

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Research subject. The composition and isotope systems of zircons and their host granites from the Krutorechensky complex (western part of the Main Uralian fault zone, Northern Urals) were investigated. Methods. The U-Pb age, trace element contents and Lu-Hf isotopes in the zircons under study were determined by LA-ICP-MS (Ulan-Ude, Ekaterinburg). TIMS was used to determine Sm-Nd isotopes in the rocks. Results and Discussion. It was shown that the morphology and composition of the main zircon group from granites confirm their magmatic origin and the absence of alteration. It means that the previously defined Vendian-Cambrian (542 Ma) age of the granites remains valid. The relics ancient (1043–122 Ma) cores were probably inherited from Isherim suite rocks. The source of such detrital grains could have been the rocks from the East-European platform basement. Young zircons (400 Ma) differing strongly from others in composition could have been formed around the already existing grains produced by a fluid generated under the action of plume activity. The source for granite melting was mainly of a crust nature: εNd(t) = –6, εHf(t) = –6…–9, initial ratio (87Sr/86Sr)i = 0.796943. In terms of lithology, the source rocks correspond to sandstones with a small admixture of clay components. The obtained information confirms the necessity to further investigate questions concerning the area of distribution and the age of the Sarankhapnorsk suite within the Krutorechensky complex, as well as the position of the eastern boundary of the Isherim block. Conclusion. The obtained results can be used in geological mapping.

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Popeko, Ludmila I., Yulia N. Smirnova, Victor A. Zaika, Andrey A. Sorokin, and Sergey I. Dril. "Provenance and Tectonic Implications of Sedimentary Rocks of the Paleozoic Chiron Basin, Eastern Transbaikalia, Russia, Based on Whole-Rock Geochemistry and Detrital Zircon U–Pb Age and Hf Isotopic Data." Minerals 10, no. 3 (March 19, 2020): 279. http://dx.doi.org/10.3390/min10030279.

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The Chiron Basin extends along the southern periphery of the Siberian Craton and the western margin of the Mongol–Okhotsk Belt. Here, we present whole-rock geochemical data (major and trace elements and Sm–Nd isotopes) along with zircon U–Pb geochronology and Lu–Hf isotopic data from Paleozoic sedimentary rocks within the Chiron Basin to investigate their provenance and tectonic history. εNd(t) values of the siliciclastics rocks of the Khara–Shibir, Shazagaitui, and Zhipkhoshi formations vary from −17.8 to −6.6, with corresponding two-stage Nd model ages (tNd(C)) ranging from 2.56 to 1.65 Ga. Detrital zircon grains from these rocks are predominantly Archean, Paleoproterozoic, and Carboniferous–Devonian in age. The data suggest that the southern flank of the Siberian Craton is the only viable source area for Archean and Paleoproterozoic zircon grains with Hf model ages (tHf(C)) of >2.20 Ga. The majority of zircon grains from sandstones from the Khara–Shibir, Shazagaitui, and Zhipkhoshi formations are Devonian–Carboniferous in age. With respect to their Hf model ages, the zircon grains can be subdivided into two groups. The first group of Devonian–Carboniferous zircon grains is characterized by relatively old (mainly Paleoproterozoic) tHf(C) model ages of 2.25–1.70 Ga and the source was the southern margin of the Siberian Craton. The second group of Devonian–Carboniferous zircon grains is characterized by significantly younger (mainly Neoproterozoic) tHf(C) model ages of 1.35–0.36 Ga, which are consistent with a juvenile source, most likely eroded island arcs. Our data, show that sedimentary rocks of the Chiron Basin likely formed in a back-arc basin on the southern periphery of the Siberian Craton facing the Paleozoic Mongol–Okhotsk Ocean.

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Santosh, M., Qiong-Yan Yang, M. Ram Mohan, T. Tsunogae, E. Shaji, and M. Satyanarayanan. "Cryogenian alkaline magmatism in the Southern Granulite Terrane, India: Petrology, geochemistry, zircon U–Pb ages and Lu–Hf isotopes." Lithos 208-209 (November 2014): 430–45. http://dx.doi.org/10.1016/j.lithos.2014.09.016.

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Gardiner, Nicholas J., Michael P. Searle, Christopher K. Morley, Laurence J. Robb, Martin J. Whitehouse, Nick M. W. Roberts, Christopher L. Kirkland, and Christopher J. Spencer. "The crustal architecture of Myanmar imaged through zircon U-Pb, Lu-Hf and O isotopes: Tectonic and metallogenic implications." Gondwana Research 62 (October 2018): 27–60. http://dx.doi.org/10.1016/j.gr.2018.02.008.

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Zhang, Zhihui, Bojie Hu, Da Zhang, Xiaolong He, Jianlin Zou, Xufeng Tian, and Yuanshun Yi. "Genesis and Significance of Late Cretaceous Granitic Magmatism in Xianghualing Tin–Polymetallic Orefield, Nanling Region, South China." Applied Sciences 12, no. 18 (September 7, 2022): 8984. http://dx.doi.org/10.3390/app12188984.

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Typical stratiform-like cassiterite–sulfide orebodies formed at 160–150 Ma cut by a steep hydrothermal vein-type orebody were discovered in the Xianghualing tin–polymetallic orefield, which implied a new phase of magmatism and mineralization later than the Late Jurassic stage. Hence, a systematic study of the characteristics and genesis of the concealed Laohuya granite, including U–Pb age, trace elements, Lu–Hf isotopes of zircons, and whole-rock major- and trace-elements, is examined in this paper. The zircon U–Pb dating yielded a Concordia age of 87.75 ± 1 Ma, confirming the existence of Late Cretaceous magmatism in the Xianghualing tin–polymetallic orefield. The Laohuya granite is classified as syenogranite and belongs to the peraluminous, high K calc-alkaline series. It is a highly evolved A2-type granite with εHf(t) values ranging from −14.97 to −7.59 and two-stage model ages (TDM2) ranging from 2939 to 2280 Ma. Combining chronology, petrochemistry, isotopic geochemistry, and previous tectonic studies, we believe that the Laohuya granite originated from the partial melting of a reworked ancient crust composed of TTGs, and its weathered sediments formed in subduction or collision zones at 2.5 Ga, controlled by the reactivation of the Chenzhou–Linwu deep fault in the extensional setting of South China during the Late Cretaceous.

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Tang, Yuyu, Hua Kong, Biao Liu, Qi Zong, Qianhong Wu, Hua Jiang, and Fucheng Tan. "Geochronology, Whole-Rock Geochemistry, and Sr–Nd–Hf Isotopes of Granitoids in the Tongshanling Ore Field, South China: Insights into Cu and W Metallogenic Specificity." Minerals 12, no. 7 (July 15, 2022): 892. http://dx.doi.org/10.3390/min12070892.

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The Qin-Hang Metallogenic Belt (QHMB), an important metallogenic belt in South China, hosts Cu and W–Sn polymetallic deposits. The Tongshanling ore field in the QHMB is characterized by the coexistence of Cu- and W-bearing polymetallic deposits, which are related to granodiorite and granite porphyry. This study examined whole-rock geochemistry, geochronology, and Sr–Nd–Hf isotopes to determine the genetic relationship between diverse ore-related granitoids (i.e., granodiorite and granite porphyry) and Cu–W metallogeny in the Tongshanling ore field. Zircon LA-ICP-MS U–Pb dating shows that the granodiorite and granite porphyry in the Tongshanling ore field were emplaced at 163.7 ± 0.4 Ma to 154.7 ± 0.6 Ma and 161.1 ± 0.3 Ma, respectively. Geochemically, the granodiorites are classified as oxidized I-type, while the highly evolved granite porphyry is reduced A-type. The Lu–Hf isotopic composition of the granodiorites is characterized by εHf(t) values ranging from –10.49 to –4.99 (average = –7.17), with corresponding TDMC ages ranging from 1524 to 1877 Ma (average = 1682 Ma). In contrast, the granite porphyry has higher εHf(t) values (–3.60 to –1.58, average = –2.78) and younger TDMC (1310–1438 Ma, average = 1387 Ma). The εNd(t) values of granodiorite are −8.06 to −7.37 and the two-stage model ages (TDM2) are 1543–1598 Ma, while the granite porphyry has higher εNd(t) values (−3.0 to −3.4) and younger TDM2 ages (1195–1223 Ma). The results show that the granodiorite and granite porphyry were formed from partial melting of different Mesoproterozoic basement rocks under varying degrees of crust–mantle interaction. Granite porphyry underwent well-recorded fractional crystallization. Compared to the Cu-forming granodiorite, the W-forming granite porphyry has a higher differentiation index, higher crystallization temperatures of zircon (average = 708 °C versus 631 °C), and lower oxygen fugacity (median ΔFMQ = –2.21 versus –1.77).

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YU, SHENG-YAO, JIAN-XIN ZHANG, SAN-ZHONG LI, DE-YOU SUN, YIN-BIAO PENG, and XI-LIN ZHAO. "Continuity of the North Qilian and North Altun orogenic belts of NW China: evidence from newly discovered Palaeozoic low-Mg and high-Mg adakitic rocks." Geological Magazine 155, no. 8 (July 27, 2017): 1684–704. http://dx.doi.org/10.1017/s0016756817000565.

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AbstractIn this study, the petrology, zircon U–Pb ages, Lu–Hf isotopic compositions, whole-rock geochemistry and Sr–Nd isotopes for newly recognized low-Mg and high-Mg adakitic rocks from the North Altun orogenic belt were determined. The results will provide important insights for understanding the continuities of the North Qilian and North Altun orogenic belts during early Palaeozoic time. The low-Mg adakitic granitoids (445 to 439 Ma) are characterized by high SiO2 (69–70 wt %), low Mg no. (43–48) and low Cr and Ni contents. In contrast, the high-Mg adakitic granitoids (425 to 422 Ma) have relatively lower SiO2 (65–67 wt %), higher Mg no. (60–62) and higher Cr and Ni contents. The low-Mg adakitic rocks have high initial 87Sr/86Sr ratios (0.7073–0.7084), negative εNd(t) (−1.9 to −4.0) and εHf(t) values (−6.8 to −2.0), and old zircon Hf model ages (1.4–1.7 Ga). In contrast, the high-Mg adakitic rocks show lower initial 87Sr/86Sr ratios (0.7044–0.7057), higher εNd(t) (−0.7 to 3.1) and positive εHf(t) values (2.0 to 6.9), with younger zircon Hf model ages (0.9–1.2 Ga). These results suggest that the low-Mg adakitic rocks were probably generated by the partial melting of thickened crust, whereas the high-Mg adakitic rocks were derived from the anatexis of delaminated lower crust, which subsequently interacted with mantle magma upon ascent. The data obtained in this study provide significant information about the geological and tectonic processes after the closure of the Altun Ocean. The continent–continent collision and thickening probably occurred during 450–440 Ma with the formation of low-Mg adakitic rocks, and the transition of the tectonic regime from compression to extension probably occurred at 425–422 Ma with the formation of high-Mg adakitic rocks. The geochemical, geochronological and petrogenetic similarities between the North Altun and North Qilian adakitic rocks suggest that these two orogenic belts were subjected to similar tectonomagmatic processes during early Palaeozoic times.

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Li, Jian, Hanlun Liu, Keyong Wang, and Wenyan Cai. "Paleoproterozoic Adakitic Rocks in Qingchengzi District, Northeastern Jiao-Liao-Ji Belt: Implications for Petrogenesis and Tectonism." Minerals 10, no. 8 (July 31, 2020): 684. http://dx.doi.org/10.3390/min10080684.

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Herein, zircon U-Pb geochronology, Lu-Hf isotopes, and whole-rock major and trace element geochemistry are presented for two Palaeoproterozoic granitic rocks in Qingchengzi district, northeastern Jiao-Liao-Ji Belt (JLJB). These new geochronological and geochemical data provide reference clues for exploring the petrogenesis and tectonic setting of Paleoproterozoic magmatic rocks in the Qingchengzi district, which further constrain the tectonic nature of the JLJB. Our zircon U-Pb dating denotes that the Paleoproterozoic magmatic events in the Qingchengzi district were emplaced at ~2163 Ma and ~1854 Ma, represented by granite porphyry and biotite granite, respectively. Geochemically, these Palaeoproterozoic rocks are characterized by high Sr (760–842 ppm), SiO2 (69.72–70.89 wt.%), and Al2O3 (15.53–16.78 wt.%) contents, low Y (2.1–9.0 ppm) and Yb (0.25–0.80 ppm) contents, which indicate an adakite affinity. Combined with Hf isotopic composition (εHf(t) = −1.5~+4.8; TDM2 = 3109~2560 Ma), we believe that the Paleoproterozoic adakitic magma originated from partial melting of the thickened lower crust material in the Meso-Neoarchean. Moreover, these rocks are enriched in light rare earth elements and large ion lithophilic elements (e.g., K, Rb, and Cs), and depleted in heavy rare earth elements and high field strength elements (e.g., Nb and Ta). These features are similar to magmatic rocks formed in an arc environment (either island arc or active continental margin) and are not consistent with an intraplate/intracontinental environment. According to this study and previous research results, we conclude that the arc–continent collision model is conducive to the Paleoproterozoic tectonic attribute of the JLJB, and the oceanic crust subduction between the Namgrim and Longgang blocks may have induced the widespread occurrence of magmatic events in the region.

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Liu, Xiao-Chi, Yuan-Bao Wu, Christopher M. Fisher, John M. Hanchar, Luke Beranek, Shan Gao, and Hao Wang. "Tracing crustal evolution by U-Th-Pb, Sm-Nd, and Lu-Hf isotopes in detrital monazite and zircon from modern rivers." Geology 45, no. 2 (December 5, 2016): 103–6. http://dx.doi.org/10.1130/g38720.1.

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32

Liu, Chaohui, Fulai Liu, Jianrong Shi, Pinghua Liu, Hong Yang, Lishuang Liu, Wei Wang, and Zhonghua Tian. "Depositional age and provenance of the Wutai Group: Evidence from zircon U–Pb and Lu–Hf isotopes and whole-rock geochemistry." Precambrian Research 281 (August 2016): 269–90. http://dx.doi.org/10.1016/j.precamres.2016.06.002.

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Guitreau, Martin, Samuel B. Mukasa, Lorne Loudin, and Sajeev Krishnan. "New constraints on the early formation of the Western Dharwar Craton (India) from igneous zircon U-Pb and Lu-Hf isotopes." Precambrian Research 302 (November 2017): 33–49. http://dx.doi.org/10.1016/j.precamres.2017.09.016.

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Schärer, Urs, Fernando Corfu, and Daniel Demaiffe. "UPb and LuHf isotopes in baddeleyite and zircon megacrysts from the Mbuji-Mayi kimberlite: constraints on the subcontinental mantle." Chemical Geology 143, no. 1-2 (November 1997): 1–16. http://dx.doi.org/10.1016/s0009-2541(97)00094-6.

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Wang, LiJuan, JinHai Yu, S. Y. O’Reilly, W. L. Griffin, Tao Sun, ZhenYang Wei, ShaoYong Jiang, and LiangShu Shu. "Grenvillian orogeny in the Southern Cathaysia Block: Constraints from U-Pb ages and Lu-Hf isotopes in zircon from metamorphic basement." Science Bulletin 53, no. 19 (August 20, 2008): 3037–50. http://dx.doi.org/10.1007/s11434-008-0262-0.

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36

Wang, Xi, Wenbin Zhu, Meng Luo, Xingmin Ren, and Xiang Cui. "Approximately 1.78 Ga mafic dykes in the Lüliang Complex, North China Craton: Zircon ages and Lu-Hf isotopes, geochemistry, and implications." Geochemistry, Geophysics, Geosystems 15, no. 8 (August 2014): 3123–44. http://dx.doi.org/10.1002/2014gc005378.

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Li, Haoran, Fengyue Sun, Liang Li, and Jiaming Yan. "The Hudesheng mafic–ultramafic intrusions in the Oulongbuluke Block, Qinghai Province, NW China: chronology, geochemistry, isotopic systematics and tectonic implications." Geological Magazine 156, no. 9 (December 19, 2018): 1527–46. http://dx.doi.org/10.1017/s0016756818000778.

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AbstractThe Hudesheng mafic–ultramafic intrusions are located in the Oulongbuluke Block, north of the Qaidam Block in Qinghai Province, NW China. We carried out a detailed study of the intrusions, including field observations, petrology, zircon U–Pb geochronology, Lu–Hf isotopes, bulk-rock major- and trace-element geochemistry, and mineral compositions, to provide a better understanding of their properties and the regional tectonic evolution. Zircon U–Pb dating on gabbro and pyroxenite samples yielded ages of 465 and 455 Ma, respectively. Geochemical data, in conjunction with the field observations and petrological features, suggest that the complex is Alaskan-type and the magma was derived from a depleted mantle source that was hydrous picritic basalt in composition and influenced by crustal contamination and slab-derived fluid metasomatism. Based on all the chronological, petrological, mineralogical and geochemical and regional geological data, we conclude that the palaeo-ocean closed diachronously from west to east between the Qaidam and Oulongbuluke blocks, and that the ocean in the east of the North Qaidam region closed after ∼455 Ma.

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Pathak, Manjari, and Santosh Kumar. "Petrology, geochemistry and zircon U–Pb–Lu–Hf isotopes of Paleoproterozoic granite gneiss from Bomdila in the western Arunachal Himalaya, NE India." Geological Society, London, Special Publications 481, no. 1 (2019): 341–77. http://dx.doi.org/10.1144/sp481-2017-169.

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AbstractFelsic magmatic bodies are exposed widely in the Bomdila region of the western Arunachal Himalaya, NE India. The litho-units of this region are primarily composed of two-mica (muscovite–biotite (ms–bt)) granite gneiss, referred to herein as the Bomdila granite gneiss (BGGn), and the metasediments of the Bomdila Group forming an integral part of the NE Lesser Himalayan thrust sheet. Phase petrology, whole-rock elemental geochemistry and zircon U–Pb–Lu–Hf isotopes of the BGGn have been investigated in order to decipher the origin and timing of felsic magmatism and its implications for understanding the pre-Himalayan tectonic environment. Modally, the BGGn can be classified into monzogranite, syenogranite and quartz-rich granitoids. The composition of muscovite (Ti = 0.03–0.07, average Na = 0.07 and AlIV = 2.50–2.90 apfu), biotite (FeOt/MgO = 3.1–4.6, 2Al⇌3Fe and Mg⇌Fe substitutions, and the presence of siderophyllite) and tourmaline (Fe/Fe + Mg = 0.56–0.96, Ca < 0.17 apfu) implies their primary magmatic nature crystallized typically in a peraluminous (S-type) felsic parental melt. This is further supported by the presence of ms–bt, whole-rock molar Al2O3/CaO + Na2O + K2O (A/CNK = 1.03–1.64) and normative corundum. Whole-rock multi-cationic parameters indicate a syn-collisional tectonic environment. However, the content of Rb (average 300 ppm) and high-field strength elements (HFSEs) in the BGGn indicates syn- to post-collisional tectonic settings. The BGGn parental melt was most likely to have been generated by dehydration melting of metasedimentary sources at middle–upper crustal depths. Geochemical modelling constrains the evolution of the parental melt of the BGGn by a moderate degree of fractional differentiation (F = 0.45) involving a biotite–plagioclase–K-feldspar–muscovite–titanite–apatite (bt–pl–Kfs–ms–ttn–ap) assemblage. Laser ablation-multicollector-inductively coupled plasma-mass spectrometry (LA-MC-ICP-MS)-analysed zircons from the BGGn yield a weighted mean 207Pb/206Pb age of 1752 ± 23 Ma as the crystallization age for the zircons in the BGGn melt, which falls well within the period of magmatism formed during the Columbia supercontinent accretionary orogen. The observed negative εHf(t) values (−1.67 to −7.99) and three-stage Hf-model ages (2818, 2586–2424 and 2393–2250 Ma) of zircons, strongly point to the involvement of ancient continental crust and source heterogeneity (Neoarchean–Paleoproterozoic continental crust) in the generation of the BGGn melt. The reworked ancient crustal components would have once been part of the northern Indian lithosphere, as indicated by the observed 207Pb/206Pb concordant ages (2436, 2136, 2013 Ma) of the inherited zircons.

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39

Wang, Li-Juan, Jin-Hai Yu, W. L. Griffin, and S. Y. O’Reilly. "Early crustal evolution in the western Yangtze Block: Evidence from U–Pb and Lu–Hf isotopes on detrital zircons from sedimentary rocks." Precambrian Research 222-223 (December 2012): 368–85. http://dx.doi.org/10.1016/j.precamres.2011.08.001.

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40

Khanna, Tarun C., V. V. Sesha Sai, Michael Bizimis, and A. Keshav Krishna. "Petrogenesis of ultramafics in the Neoarchean Veligallu greenstone terrane, eastern Dharwar craton, India: Constraints from bulk-rock geochemistry and Lu-Hf isotopes." Precambrian Research 285 (October 2016): 186–201. http://dx.doi.org/10.1016/j.precamres.2016.09.020.

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41

Huang, Zongying, Xiaoping Long, Alfred Kröner, Chao Yuan, Qiang Wang, Min Sun, Guochun Zhao, and Yujing Wang. "Geochemistry, zircon U–Pb ages and Lu–Hf isotopes of early Paleozoic plutons in the northwestern Chinese Tianshan: Petrogenesis and geological implications." Lithos 182-183 (December 2013): 48–66. http://dx.doi.org/10.1016/j.lithos.2013.09.009.

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42

Lizuka, T., K. Horie, T. Komiya, S. Maruyama, T. Hirata, and H. Hidaka. "Reworking of Hadean continental crust in the Acasta Gneiss Complex of NW Canada: Evidence from zircon U–Pb and Lu–Hf isotopes." Geochimica et Cosmochimica Acta 70, no. 18 (August 2006): A369. http://dx.doi.org/10.1016/j.gca.2006.06.558.

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43

Yu, JinHai, LiJuan Wang, S. Y. O’Reilly, LiangShu Shu, and Tao Sun. "Paleoproterozoic basement beneath the southern Jiangxi Province: Evidence from U-Pb ages and Lu-Hf isotopes in zircons from the Doushui lamprophyre." Science Bulletin 54, no. 9 (March 10, 2009): 1555–63. http://dx.doi.org/10.1007/s11434-009-0095-5.

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44

Liu, Rui, HanWen Zhou, Li Zhang, ZengQiu Zhong, Wen Zeng, Hua Xiang, Song Jin, XinQian Lu, and ChunZhong Li. "Paleoproterozoic reworking of ancient crust in the Cathaysia Block, South China: Evidence from zircon trace elements, U-Pb and Lu-Hf isotopes." Science Bulletin 54, no. 9 (March 4, 2009): 1543–54. http://dx.doi.org/10.1007/s11434-009-0096-4.

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45

Gao, Min, Zhen-Jie Zhang, Qiu-Ming Cheng, and Djordje Grujic. "Zircon U-Pb and Lu-Hf isotopes of Huai'an complex granites, North China Craton: Implications for crustal growth, reworking and tectonic evolution." Gondwana Research 90 (February 2021): 118–34. http://dx.doi.org/10.1016/j.gr.2020.10.015.

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46

Petersson, Andreas, Anders Scherstén, and Axel Gerdes. "Extensive reworking of Archaean crust within the Birimian terrane in Ghana as revealed by combined zircon U-Pb and Lu-Hf isotopes." Geoscience Frontiers 9, no. 1 (January 2018): 173–89. http://dx.doi.org/10.1016/j.gsf.2017.02.006.

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47

Iizuka, Tsuyoshi, Ian H. Campbell, Charlotte M. Allen, James B. Gill, Shigenori Maruyama, and Frédéric Makoka. "Evolution of the African continental crust as recorded by U–Pb, Lu–Hf and O isotopes in detrital zircons from modern rivers." Geochimica et Cosmochimica Acta 107 (April 2013): 96–120. http://dx.doi.org/10.1016/j.gca.2012.12.028.

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48

Wang, Song-Jie, Hans-Peter Schertl, and Yu-Mao Pang. "Geochemistry, geochronology and Sr–Nd–Hf isotopes of two types of Early Cretaceous granite porphyry dykes in the Sulu orogenic belt, eastern China." Canadian Journal of Earth Sciences 57, no. 2 (February 2020): 249–66. http://dx.doi.org/10.1139/cjes-2019-0003.

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Анотація:

Late Mesozoic granitic rocks are widely distributed in the Sulu orogenic belt, but the source, tectonic affinity, and associated geodynamic setting that produced the respective magmas remain controversial. To provide insights into these issues, we present field-based petrological, whole-rock major and trace element and Sr–Nd isotope geochemical, zircon U–Pb dating, and Lu–Hf isotope studies on two types of granite porphyry dykes that are newly recognized from the central Sulu belt. U–Pb dating of magmatic zircons from both types yields consistent ages that vary between 124 ± 2 and 118 ± 2 Ma, constraining the timing of intrusion as Early Cretaceous. The granitic rocks have high-K calc-alkaline peraluminous compositions with low Mg# values and are characterized by fractionated rare earth element patterns with strong depletion in high field strength elements. Compared with type I of the granite porphyry dykes, type II exhibits higher SiO2 but slightly lower Na2O and K2O abundances, contains higher Rb/Sr and 87Sr/86Sr ratios, and shows more pronounced negative Eu, Sr, and Ba anomalies. Both types I and II have high initial 87Sr/86Sr ratios of 0.709–0.711 and negative εNd(t) values of −19.8 to −18.4. The magmatic zircons possess negative εHf(t) values of −29.1 to −20.8, with mostly Neoarchean Hf model ages of 3001–2478 Ma. These features, together with the presence of Neoproterozoic inherited zircons, indicate that the two types of granite porphyries successively crystallized from a joint granite magma that derived from partial melting of the continental crust of the Yangtze Craton. Therefore, an interrelationship between the granite porphyry dykes and massive magmatic granitoids from adjacent regions in the Sulu belt may be documented, recording evidence of a joint ancient crustal reworking and recycling in a fossilized continental subduction zone during the Early Cretaceous.

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Chervyakovskaya, M. V., S. L. Votyakov, and V. S. Chervyakovskiy. "Study of Lu/Hf isotopic composition of zircons using a Neptune Plus multicollector inductively coupled plasma mass spectrometer with an NWR 213 laser ablation attachment." Аналитика и контроль 25, no. 3 (2021): 212–21. http://dx.doi.org/10.15826/analitika.2021.25.3.005.

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A technique of analyzing the isotopic composition of Lu and Hf and for determining the Lu/Hf and Hf/Hf isotopic ratios in zircons is presented using a Neptune Plus (Thermo Scientific) mass spectrometer with inductively coupled plasma with an NWR 213 (ESI) laser ablation attachment. On the example of Mud Tank, GJ-1, 91500, Plesovice and Temora-2 standard zircon samples, the uncertainty of a single measurement of the 176Hf/177Hf ratio has been obtained in the range of 0.002-0.008% in the form of 2σ (with a crater diameter of 50 μm; when it decreased to 25 μm the measurement uncertainty of the 176Hf/177Hf ratio increased by 1.5-2 times). Under the optimum parameters of the NexION 300S with NWR213 with the aim of increasing the locality of the sequential study of U/Pb and Lu/Hf isotope systems, a comparative characteristic of the application of two approaches has been obtained: in adjacent grain areas (approach 1) and in one crater (approach 2). The metrological characteristics of analyzing the isotopic composition of Lu and Hf and for determining the Lu/Hf and Hf/Hf isotopic ratios in zircons have been determined. To establish the application limits of the developed technique, the factor planning of the experiment has been developed. It was established that with a Lu/Hf ratio of 1/50 or more, the technique is not recommended to be applied due to the incorrect allowance of the isobaric effect. The procedures for measuring and calculating the Lu/Hf isotopic ratios of the isotope system in zircon have been tested on zircon grains (samples NP-46 and NP-47) of the Neplyuevsky pluton (South Urals). The data obtained was in satisfactory agreement with the data of the A. P. Karpinsky Russian Geological Research Institute (VSEGEI).

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Li, Hang, Ming Wang, Xiao-Wen Zeng, An-Bo Luo, and Shi-Bin Feng. "Zircon U-Pb and Lu-Hf isotopes and geochemistry of granitoids in central Tibet: Bringing the missing Early Jurassic subduction events to light." Gondwana Research 98 (October 2021): 125–46. http://dx.doi.org/10.1016/j.gr.2021.06.006.

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