Petrogenesis of Early Cretaceous volcanic rocks of the Manketouebo Formation in the Wuchagou region, central Great Xing’an Range, NE China, and tectonic implications: geochronological, geochemical, and Hf isotopic evidence

Abstract

This study presents new whole-rock major and trace element geochemistry, zircon U-Pb ages, and Hf-isotope compositions for volcanic rocks from the Manketouebo Formation of the central Great Xing'an Range, NE China. These data provide precise ages and information on the petrogenesis and source of the magmas that formed this formation, furthering our understanding of the geodynamic setting of the large-scale late Mesozoic magmatism in the Great Xing'an Range and other areas in NE China. The Manketouebo Formation in the study area is dominated by rhyolites and rhyolitic tuffs with minor trachydacites. The LA-ICP-MS zircon U-Pb dating indicates that these volcanic rocks formed between 143 and 139 Ma. The volcanic rocks contain high silica (66.70-79.91 wt.%) and total alkali (5.93-9.72 wt.%) concentrations, and low concentrations of MgO (0.08-1.15 wt.%), total FeO (0.68-4.50 wt.%), and CaO (0.10-2.56 wt.%). They are enriched in large-ion lithophile elements (LILEs; e.g. Rb, Th, and U) and light rare earth elements (LREEs), and depleted in high field strength elements (HFSEs; e.g. Nb, Ta, Ti, and P) and heavy rare earth elements (HREEs), indicating that they are similar to highly fractionated I-type igneous rocks. All of the magmatic zircons from the analysed samples have high initial 176 Hf/ 177 Hf ratios (0.282900-0.283093), positive ε Hf (t) values (7.48-14.19), and young Hf two-stage model ages (954-344 Ma) that suggest the primary magma that formed the volcanic rocks of the Manketouebo Formation was derived from the partial melting of Neoproterozoic to Phanerozoic juvenile crustal material, indicating in turn that significant crustal growth occurred at this time within the Xing'an Terrane. These data, combined with previous research into the spatial-temporal distribution of Mesozoic volcanic rocks in NE China, suggest that the Early Cretaceous magmatism in the Great Xing'an Range was influenced by both the subduction of the Palaeo-Pacific Plate and the closure of the Mongol-Okhotsk Ocean. This was a crucial period in the transformation from the Mongol-Okhotsk Ocean to the Palaeo-Pacific tectonic regimes. In summary, the early stages of Early Cretaceous magmatism in this area were related to the closure of the Mongol-Okhotsk Ocean, whereas the later stages of magmatism in this area and elsewhere in NE China were related to the subduction of the Palaeo-Pacific Plate. ARTICLE HISTORY

Geodynamic Evolution of Flat‐Slab Subduction of Paleo‐Pacific Plate: Constraints From Jurassic Adakitic Lavas in the Hailar Basin, NE China

“…All Sr‐Nd isotopic ratios are corrected to 165 Ma. Hf isotopic data for the Mesozoic crust‐derived rocks in the HB and northern GXR are from Li, Ding, et al, , Li et al, ), Tang et al (, ), Hu et al (), Zhou et al (), Dong et al (, ), Ji et al (), Gou et al (), and Ji et al (). Hf isotopic data for the Mesozoic mantle‐derived rocks in the HB and northern GXR are from Tang et al (), Wang, Tang, et al (), Liu et al (), Gou et al (), and Zhang et al ().…”

“…The Mesozoic Mongol‐Okhotsk Suture Belt, situated in the northwest of NE China, was formed by diachronous closure of the Mongol‐Okhotsk Ocean (Ouyang et al, ; Zorin, ). The subduction of the Paleo‐Pacific Plate paired with the closure of the Mongol‐Okhotsk Ocean gave rise to a series of Mesozoic tectonomagmatic events in NE China, including crust‐derived silicic magmatism, fold‐and‐thrust deformation, formation of fault‐bounded basins, and deep crustal exhumation (Zhang et al, ; Wu et al, ; Xu et al, ; Ouyang et al, ; Ji et al, , ; Figure c).…”

Geochemistry of high‐Nb basalt‐andesite in the Erguna Massif (NE China) and implications for the early Cretaceous back‐arc extension

“…NE China, located in the eastern section of the world famous Central Asian Orogenic Belt, as shown in Figure , has been jointly influenced by the Paleo‐Asian Ocean closure, Paleo‐Pacific, and Mongol–Okhotsk subductions (e.g., Chen, Xia, Ingrin, Deloule, & Bi, ; Kelty, Yin, Dash, Gehrels, & Ribeiro, ; Y. Li et al, ; Tang et al, ; Z. J. Wang et al, ; Zhang, ). One of its most notable characteristics is the large‐scale Middle Jurassic to Early Cretaceous volcanism, which have been classified into six magmatic flare‐ups including the Wanbao (J 2 w ), Tamulangou (J 2 tm ), Manketouebo (J 3 mk ), Manitu (J 3 mn ), Baiyingaolao (K 1 b ), and Meiletu (K 1 m ) formations (e.g., Dong et al, ; Ji et al, ; Li, Liu, Xu, Li, & Zhang, ; Sun et al, ). For their petrogenesis, four distinctive geodynamics have been proposed involving (a) a mantle plume (e.g., Deng et al, ; T. Wang et al, ), (b) post‐orogenic gravitational collapse and/or subduction‐induced back‐arc extension related to closure of the Mongol–Okhotsk Ocean (e.g., Cogne, Kravchinsky, Halim, & Hankard, ; Fritzell, Bull, & Shephard, ; Z. H. Wang et al, ; Yang, Guo, Song, Li, & He, ), (c) post‐orogenic gravitational collapse and subsequent extension related to closure of the Paleo‐Asian Ocean (e.g., Xu et al, ; Yang, Sun, Gou, & Hou, ), and (d) arc/back‐arc extension and asthenospheric upwelling induced by the Paleo‐Pacific subduction (e.g., Dong et al, ; Tang, Xu, Wang, Zhao, & Li, ; Wang et al, ; Zhang et al, ).…”

Geochronology and Geochemistry of Early Cretaceous Granitic Plutons in the Xing'an Massif, Great Xing'an Range, NE China: Petrogenesis and Tectonic Implications

“…2). These Mesozoic volcanic rocks are mainly acidic volcanic rocks, with minor intermediate volcanics, and they were mainly generated by partial melting of lower crustal materials (Zhang, 2006(Zhang, , 2009Zhang et al, 2010a;Dong et al, 2014;Ji et al, 2016b). Together, it is difficult to explain the formation of Early Cretaceous Meiguifeng and Arxan plutons in the Great Xing'an Range through the second model.…”