The Wulonggou metaluminous A2-type granites in the Eastern Kunlun Orogenic Belt, NW China: Rejuvenation of subduction-related felsic crust and implications for post-collision extension

Xin, Wei; Sun, Fengyue; Li, Liang; Jin, Yan; Zhang, Yuting; Wang, Yingchao; Shen, Ting-Shuo; Yang, Yue

doi:10.1016/j.lithos.2018.05.005

Cited by 61 publications

(23 citation statements)

References 101 publications

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“…A‐type granites could be also classified into reduced and oxidized subtypes (Dall'Agnol & Oliveira, ; Xin et al, ). The reduced A‐type granites have relatively anhydrous magmatic sources (perhaps 2–3 wt.% H 2 O contents), with high melting temperature (>900°C).…”

Section: Discussionmentioning

confidence: 99%

“…Griffin et al, 2000); f Lu/Hf of average continental crust is −0.55 (Griffin et al, 2002). A-type granites could be also classified into reduced and oxidized subtypes (Dall'Agnol & Oliveira, 2007;Xin et al, 2018 In the FeOt/(FeOt+MgO) versus Al 2 O 3 diagram (Figure 10a), most of the data plot in the reduced A-type granites field. By comparison with the water-saturated minima in the granitic system, an estimate of the depth of melting can be inferred if the magma has experienced minimal changes in composition since melt generation (Anderson & Cullers, 1978;Anderson & Bender, 1989).…”

Section: Petrogenesis Of Erfendi Granitesmentioning

confidence: 99%

“…The record of the magmatic activity is an effective way to understand the growth and evolution history of the accretionary orogens (Glen, Quinn, & Xiao, ; Zhang et al, ). Post‐collision or post‐orogenic magmatism often represents intense upwelling of the asthenosphere, especially the emplacement of voluminous A 2 ‐type granites in an extensional tectonic environment (Li, Wilde, Wang, Xiao, & Guo, ; Sami et al, ; Wu, Sun, Jahn, & Wilde, ; Xin et al, ). The North China Plate (NCP) is a major continental plate with a complex tectonic history.…”

Section: Introductionmentioning

confidence: 99%

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Characteristics of Devonian extensional magmatic activity in the Jiefangyingzi area, northern margin of the North China Plate

Wang

Liu

et al. 2019

Geological Journal

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This paper presents geochronological, geochemical, and isotopic data relating to Devonian magmatic activity in the Jiefangyingzi area, northern margin of the North China Plate (NCP). LA‐ICP‐MS zircon U–Pb dating indicates that the Erfendi granites formed in the Middle Devonian and yield a concordant weighted mean age of 384.7 ± 2.5 Ma. The zircons have negative εHf(t) values ranging from −5.8 to −31.3 and two‐stage Hf‐model ages of TDM2 = 1,735–3,217 Ma. 206Pb/238U ages of zircon grains from a quartz–schist sample in the Shaiwusu Formation vary from 410 to 322 Ma, with a peak at 380 Ma, indicating that magmatic activity peaked during the Late Devonian. The Erfendi granites are silica‐ and alkali‐rich and calcium‐ and magnesium‐poor. The Erfendi granites belong to peraluminous rocks and have clear negative Eu anomalies (δEu = 0.49–0.84); P, Ti, and Nb depletions; Nd, Zr, and U enrichments; and high Ga/Al ratios, similar to aluminous A‐type granites. This suggests the Erfendi granites were generated by partial melting of lower crustal rocks. Geochemically, the Erfendi granites are A2‐type granites, reflecting a post‐collision tectonic setting. The southward subduction of the Palaeo‐Asian Oceanic Plate during the Early Palaeozoic formed Bainaimiao volcanic arc at the northern NCP and Deyanqimiao island arc. The collision between the Deyanqimiao island arc and the Bainaimiao volcanic arc was recorded by the Xibiehe molasse deposition and the Badangshan volcanic rocks at the northern margin of the NCP during the Late Silurian to Early Devonian. As a consequence, the Jiefangyingzi area experienced intense post‐collision extensional magmatism during the Middle Devonian, which generated massive A2‐type granites at the northern margin of the NCP. This collision was also recorded by the back‐arc deposition of the Late Carboniferous Shaiwusu Formation.

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Section: Discussionmentioning

confidence: 99%

Section: Petrogenesis Of Erfendi Granitesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Characteristics of Devonian extensional magmatic activity in the Jiefangyingzi area, northern margin of the North China Plate

Wang

Liu

et al. 2019

Geological Journal

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“…Some of the mafic-ultramafic complexes and A-type granitoids in the EKOB have similar ages, as exemplified by the Xiarihamu I mafic-ultramafic complex (423 ± 1 Ma; Wang et al [63]), the Xiarihamu II mafic-ultramafic complex (424 ± 1 Ma; Peng et al [7]), and the Baiganhu A-type moyite and monzonitic granites (ages of 422 ± 3 and 421 ± 3.7 Ma, respectively; Li et al [64]). The Wulonggou A2-type granite, which formed at 426-424 Ma, represents the earliest evidence for a post-orogenic tectonic setting in this area (Xin et al [9]). The presence of these coeval middle Silurian mafic-ultramafic complexes and A-type granites provide evidence of formation in a post-collisional tectonic environment.…”

Section: Geodynamic Implicationsmentioning

confidence: 99%

“…The eastern Kunlun orogenic belt (EKOB) is located along the northern margin of the Tibetan Plateau in western China [1] (Figure 1a): Previous researches determined that the orogenic events are associated with the subduction of the proto-and paleo-Tethyan oceans [4,5]. This Silurian-Devonian tectonism also generated widespread magmatic rocks, including granites of slightly variable ages and minor amounts of mafic-ultramafic intrusions [6][7][8][9]. The origin of the latter remain poorly investigated despite the fact that some of them are mineralized.…”

Section: Introductionmentioning

confidence: 99%

Geochemistry, Geochronology, and Hf-S-Pb Isotopes of the Akechukesai IV Mafic-Ultramafic Complex, Western China

et al. 2019

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The Akechukesai IV mafic–ultramafic complex, located in the western segment of the eastern Kunlun orogenic belt (EKOB), represents a newly-discovered complex, containing Ni ores at grades of up to 0.98% Ni. It is dominated by olivine pyroxenite, pyroxenite, and gabbro units. The gabbros are enriched in lithophile elements (e.g., Rb, U, and K) and light rare-earth elements (LREE), with negative anomalies in high field-strength elements, except Zr, Ta. Nb/Ta(∼5) and Zr/Hf (∼10) ratios lower than the primitive mantle and chondrites, respectively, indicate the influence of the mantle metasomatic process or fractionation of accessory mineral phases. Zircon U–Pb dating of the gabbro yielded an age of 423.9 ± 2.6 Ma, indicating that the complex formed contemporaneously with the Xiarihamu Ni deposit (423 ± 1 Ma). The gabbro has negative εHf(t) values (−11.3 to −1.2) with corresponding TDM1 ages of 1535–1092 Ma. The vein-like and disseminated mineralization (i.e., pyrite and pyrrhotite) have δ34S values of 13.1‰–13.4‰ and 5.0‰–8.5‰, respectively, suggesting that the magmas that formed the complex assimilated crustal sulfur. They yield 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values of 17.323–18.472, 15.422–15.626, and 37.610–38.327, respectively, indicating Pb derived from multiple sources (i.e., mantle crustal sources). Geochemical and Hf–S–Pb isotopic characteristics suggest that the complex formed from a primitive magma derived by partial melting of a spinel- and garnet-bearing lherzolite mantle at variable degree of 5%–10%. This source region was geochemically enriched by previous interaction with slab-related fluids. Tectonic reconstruction suggests that the Akechukesai IV complex was generated in a post-collisional extensional environment.

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Anisian granodiorites and mafic microgranular enclaves in the eastern Kunlun Orogen, NW China: Insights into closure of the eastern Paleo–Tethys

Wei

Santosh

et al. 2020

Geological Journal

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Granitoids and their mafic microgranular enclaves (MMEs) provide important insights into magmatic activity and tectonic evolution associated with accretionary orogens. Here we investigate the origin of Middle Triassic granodiorites and MMEs in the central segment of the eastern Kunlun Orogen (EKLO) in NW China, which is an important region to evaluate the history of closure of the Paleo–Tethys, through zircon U–Pb geochronology, major and trace element geochemistry, and Sr–Nd–Hf isotopes. Zircon U–Pb ages indicate the coeval formation of granodiorites and their MMEs during the Anisian (ca. 245 Ma). The granodiorites are calc‐alkaline and metaluminous with high SiO2 contents and Mg# values. They are characterized by enrichment of LREEs and LILEs, and depletion of Nb, Ta, and Ti. Their Sr–Nd –Hf isotopic compositions indicate that the magmas were derived from enriched mantle and Paleoproterozoic basement. The monzodioritic‐dioritic MMEs exhibit low SiO2 contents and high Al2O3 and MgO with high Mg# values, enrichment in LREEs and LILEs, and depletion in HFSEs with negative Nb, Ta, Ti, and P. In contrast, the gabbroic MMEs show higher Mg# values and Cr contents. Both types of MMEs have Sr–Nd–Hf isotopic compositions similar to the host granodiorites, and originated from mixing of lower crust‐ and enriched mantle‐derived magmas. The mantle‐derived sources were metasomatized by slab‐derived melts. The Middle Permian to Middle Triassic magmatism, metamorphism, sedimentation, and tectonics in the EKLO suggest northward subduction of the Paleo–Tethys Ocean as represented by the A'nyemaqen Ocean. The magma mixing that generated the Anisian granodiorites and MMEs was likely associated with slab break‐off of the Paleo–Tethys Ocean. The formation of the Anisian magmatic rocks in the EKLO suggest that the cessation of subduction of the Paleo–Tethys Ocean and onset of collision took place during the late stage of Middle Triassic.

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The Wulonggou metaluminous A2-type granites in the Eastern Kunlun Orogenic Belt, NW China: Rejuvenation of subduction-related felsic crust and implications for post-collision extension

Cited by 61 publications

References 101 publications

Characteristics of Devonian extensional magmatic activity in the Jiefangyingzi area, northern margin of the North China Plate

Characteristics of Devonian extensional magmatic activity in the Jiefangyingzi area, northern margin of the North China Plate

Geochemistry, Geochronology, and Hf-S-Pb Isotopes of the Akechukesai IV Mafic-Ultramafic Complex, Western China

Anisian granodiorites and mafic microgranular enclaves in the eastern Kunlun Orogen, NW China: Insights into closure of the eastern Paleo–Tethys

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