Permian ridge subduction in the easternmost Central Asian Orogenic Belt: Magmatic record using Sr-Nd-Pb-Hf-Mg isotopes

Wang, Feng; Xing, Kai‐Chen; Xu, Wen‐Liang; Teng, Fang‐Zhen; Xu, Yi‐Gang; Yang, Debin

doi:10.1016/j.lithos.2021.105966

Cited by 10 publications

(2 citation statements)

References 67 publications

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“…All chemical preparations were made on class 100 workbenches within a class 1000 over-pressured clean laboratory. Detailed procedures and instrumentation for Sr-Nd-Pb-Hf isotopic analyses for this laboratory are the same as those described in Li et al (2018) and Wang et al (2021). During the Sr-Nd isotopic analyses, the NIST SRM 987 standard solution yielded 87 Sr/ 86 Sr ratio of 0.710244±0.000022 (2SD, n=32) and the JNdi-1 standard gave 143 Nd/ 144 Nd ratio of 0.512118±0.000015 (2SD, n=31).…”

Section: Whole-rock Sr-nd-pb-hf Isotopic Analysesmentioning

confidence: 99%

Cenozoic intraplate volcanism in central Asia: Mantle upwelling induced by India-Eurasia collision

Wang

Jian

et al. 2022

GSA Bulletin

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Most of Earth’s volcanism occurs at tectonic plate boundaries associated with subduction or rifting processes. The mantle plume hypothesis is an important supplement to plate tectonics for explaining some high-volume intraplate volcanic fields. However, many intraplate magmatic provinces occur as low-volume, monogenetic basaltic-suite fields that are neither associated with plate-boundary processes nor attributable to mantle plumes, and the origin of such magmatism has long been debated. Identification of their source characteristics and possible mechanisms that trigger mantle melting will provide essential insights into Earth’s mantle heterogeneity and also develop our knowledge of tectonic plate movement through time. Here, we report new geochronology, mineral chemistry (especially olivine), and whole-rock chemical and Sr-Nd-Pb-Hf isotopic compositions on Cenozoic intracontinental alkaline basalts from the northwestern Tarim craton (central Asia), aiming to better assess the origin of Earth’s low-volume effusive intraplate volcanic fields. The basalts (ca. 42 Ma) have olivine (e.g., mean Ni abundances of ∼2250 ppm, mean Mn/Zn ratios of 13.7) and whole-rock chemistry consistent with their derivation from a mixed peridotite-pyroxenite source. Moderately depleted Sr-Nd-Pb-Hf isotopes (87Sr/86Sr = 0.7039−0.7053; εNd = +4.0 to +5.5; 206Pb/204Pb = 18.247−18.535; εHf = +8.1 to +8.7) require a young (ca. 500 Ma) oceanic crust recycled into the source, possibly related to subduction events during the assembly of Pangea. Estimated thermal-chemical conditions indicate that the original melting occurred in a relatively dry (H2O = 1.4 ± 0.9 wt%) and reduced (logfO2 ΔFMQ = −0.97 ± 0.21, where FMQ is fayalite-magnetite-quartz) asthenosphere under a mantle potential temperature of ∼1420 °C and a pressure of ∼3.7 GPa (corresponding to a depth of ∼120 km). Combining these data with regional tectonic history and geophysical data (high-resolution P-wave tomography), we propose that the long-lasting India-Eurasia collision triggered asthenospheric upwelling, focusing melts along translithospheric zones of weakness; this model provides a robust explanation for the observed Cenozoic intracontinental volcanism in central Asia. The integrated geochemical and geophysical evidence reveals that plate subduction−induced mantle upwelling represents a likely mechanism for the generation of many regions of plume-absent intraplate magmatism within continents.

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Section: Whole-rock Sr-nd-pb-hf Isotopic Analysesmentioning

confidence: 99%

Cenozoic intraplate volcanism in central Asia: Mantle upwelling induced by India-Eurasia collision

Wang

Jian

et al. 2022

GSA Bulletin

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“…The widespread latest late Permian to Middle Triassic adakitic magmatism in the southeastern CAOB marked the final suturing of the Palaeo-Asian Ocean , with resultant thickening of the lower crust up to ~59 km (Hui et al 2021). In addition, Wang et al (2021) further proposed another early-middle Permian ridge subduction model based on the formation of multi-type 'abnormal' igneous rocks (282-268 Ma) along the western margin of the Khanka Block. The high heat condition is recorded by the decomposition reactions of magnesite constraints of Mg isotopes and high zircon saturation temperatures of felsic rocks (855-935 °C).…”

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confidence: 99%

Late Palaeozoic tectonic evolution of the eastern Palaeo-Asian Ocean: new evidence from the early Permian arc magmatic suites in the Kulun region

Jing

Yang

et al. 2022

Geol. Mag.

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Late Palaeozoic igneous rock associations in response to subduction, accretion, and final closure of the eastern Palaeo-Asian Ocean play a significant role in understanding the geodynamic evolution of the southeastern Central Asian Orogenic Belt. Previous studies have identified a Permian arc magmatic belt associated with the southward-dipping subduction of the eastern Palaeo-Asian Ocean along the Solonker–Changchun suture zone. The genetic mechanism and associated geodynamic settings are of great importance in deciphering the evolution of the eastern Palaeo-Asian Ocean. This paper presents zircon U–Pb–Hf isotope and whole-rock geochemical analyses for a suite of magmatic rocks including the early Permian diorite porphyrites (ca. 281.0 Ma), andesites (ca. 276 Ma) and rhyolites (ca. 275 Ma) in the Kulun region. The diorite porphyrites and andesites have high SiO2 and total alkali contents, and low MgO contents and Mg no. values, with enrichments in large ion lithophile elements and depletions in high-field-strength elements. These geochemical characteristics, together with low-Sr and high-Yb contents, a weak concave-upward shape of middle rare earth elements and negative Eu anomalies, suggest that these intermediate igneous rocks were generated by partial melting of amphibolitic lower crust at a crustal depth of 30–40 km. The rhyolites have heterogeneous isotopic compositions, with ϵHf(t) values and TDM2 ages of –20.8 to +0.5 and 3578∼1494 Ma, implying that they were likely derived from partial melting of a mixed source dominated by recycled ancient crust with minor juvenile crustal materials. The rhyolites show potassic affinity with relatively high K2O and very low Na2O, which was attributed to liquid immiscibility of felsic magma and subsequent limited fractional crystallization of plagioclase. The regional igneous associations, metamorphic events, and coeval sedimentary rocks along the Solonker–Changchun suture zone indicate that the early Permian igneous rocks were formed in an active continental arc environment in response to southward subduction of the eastern Palaeo-Asian Ocean.

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Petrogenesis of Early Mesozoic volcanic rocks in southeastern NE China: Geochemical and Sr–Nd–Pb–O isotopic evidences

Wei

Pei

et al. 2023

Lithos

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Permian ridge subduction in the easternmost Central Asian Orogenic Belt: Magmatic record using Sr-Nd-Pb-Hf-Mg isotopes

Cited by 10 publications

References 67 publications

Cenozoic intraplate volcanism in central Asia: Mantle upwelling induced by India-Eurasia collision

Cenozoic intraplate volcanism in central Asia: Mantle upwelling induced by India-Eurasia collision

Late Palaeozoic tectonic evolution of the eastern Palaeo-Asian Ocean: new evidence from the early Permian arc magmatic suites in the Kulun region

Petrogenesis of Early Mesozoic volcanic rocks in southeastern NE China: Geochemical and Sr–Nd–Pb–O isotopic evidences

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