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The Beishan orogenic zone is a key area to understand evolution of the Central Asian Orogenic Belt that is an accretionary factory well‐enough preserved in the Paleozoic. In early Paleozoic, the tectonic mélange zone containing the coherent unit and mélange unit is triggered by the complicated accretionary process of the Beishan area. The early Paleozoic tectonic evolution of the Beishan orogenic zone is investigated in this study using sedimentology and stratigraphic correlations of the lowe Paleozoic deposits. From the Cambrian to the middle Ordovician, this region was characterized by geographically extensive, flat‐bedded siliceous mudstone, indicating the existence of a large ocean basin. The oceanic plate entered the convergence phase in terms of the Wilson Circle during the Middle Ordovician, when numerous magmatic arcs formed along two opposite sides of the ocean. The magmatic arcs became the widest during the Silurian, suggesting that the Hongliuhe‐Niujuanzi‐Xichangjing Ocean (HNX; a southern branch of the Paleo Asian Ocean) was reduced to a small residual ocean in the central Beishan region by that time, and probably lasted till the Carboniferous or later by newly published data. [ABSTRACT FROM AUTHOR]

This paper investigates the petrogenesis of the Xinxian granitic batholith and its tectonic implications for the Dabie orogen. Two Xinxian granites yield Early Cretaceous U/Pb ages of 122.7 ± 1.3 Ma and 123.6 ± 2.2 Ma. The granites are metaluminous differentiated I-type granites, with A/NKC ranging from 0.90 to 0.96. The chondrite-normalised REE patterns display significant LREE/HREE enrichments with moderate negative Eu anomalies (Eu/Eu = 0.30 ~ 0.85). The granites show enrichments in large-ion lithophile elements (LILEs, e.g. Rb, K, Th and U) and depletions in Sr, Ba and high field strength elements (HFSEs, e.g. Nb, Ta and Ti). Inherited zircons of different age (Neoproterozoic, one Early Proterozoic, one Archean and two Triassic inherited metamorphic zircons) are identified. The Early Cretaceous magmatic zircons contain enriched Hf isotopes with ε ( t) values ranging from −26.9 to −18.7 (average = −22.5), more enriched than their probable alleged source, i.e. the Dabie Complex, represented by the Neoproterozoic and Triassic inherited zircons. Thus, the Archean and Early Proterozoic crustal materials may represent an enriched end member source for the parental magma of the Xinxian granites. Provenance analysis of the magmatic zircons in the North China and Yangtze blocks demonstrates that the Early Proterozoic inherited zircon in Xinxian has North China affinity. Thus, we proposed a multiple-sourced petrogenetic model for the Xinxian granitic batholith, which suggests that the batholith was formed by the remelting of a mixed crustal assemblage, including the Archean and Early Proterozoic crust of the North China Block, the Neoproterozoic crust of the Yangtze Block, as well as some Triassic collision-related ultra-high pressure (UHP) metamorphic rocks. [ABSTRACT FROM AUTHOR]

Abstract: We undertook LA-ICP-MS U–Pb dating of detrital zircons from Late Paleozoic sedimentary rocks in eastern Heilongjiang Province, NE China, with the aim of constraining the tectonic evolution of the eastern segment of the Central Asian Orogenic Belt (CAOB). Detrital zircons from quartz sandstone of the Devonian Heilonggong Formation in the Zhangguangcai Range yield age populations of ∼2503, ∼1833, ∼903, ∼802, and 551–403Ma. Zircons from quartz sandstone of the Devonian Baoquan Formation in the Lesser Xing''an Range yield age clusters at ∼2500, ∼800, and 489–425Ma. These ages reveal that: (1) rocks from the Heilonggong and Baoquan formations were deposited after 391 and 413Ma, respectively; (2) these rocks were sourced from regions with rocks as old as ∼2500Ma, with dominant age populations of ∼2500, ∼1833, 903–800, and 551–403Ma; and (3) in addition to new lower crust accreted during the Phanerozoic (as revealed by voluminous Phanerozoic granitoids with positive εNd values within the CAOB), it appears that several remnants of an ancient Precambrian basement occur adjacent to these Late Paleozoic basins (e.g., the Shangzhi, Tangyuan, and Baoqing basins) that occur within microcontinental massifs including the Songnen–Zhangguangcai Range, Xing''an, and Erguna massifs. Detrital zircons from quartz sandstone of the Devonian Heitai Formation on the eastern margin of the Jiamusi Massif yield peak age populations of 569, 542, 509, and 484Ma, similar to those obtained from zircons within the Mashan Group of the Jiamusi Massif. These age data indicate that: (1) deposition of the Heitai Formation on the eastern margin of the Jiamusi Massif had started by 484Ma, and (2) these sediments were sourced entirely from the Jiamusi Massif. The widespread occurrence of detrital zircons with ages of 480–550Ma within Late Paleozoic basins in the Lesser Xing''an–Zhangguangcai Ranges and the Jiamusi Massif, combined with the presence of a Caledonian (445–499Ma) I-type granitoid belt in the Lesser Xing''an–Zhangguangcai Ranges, indicates that amalgamation of the Songnen–Zhangguangcai Range and Jiamusi massifs took place before the Early Devonian, probably during the late stage of the Early Paleozoic (after ∼445Ma). [Copyright &y& Elsevier]