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Understanding the temporal and spatial evolution of the North China Craton (NCC) basement, formed by amalgamation, is a crucial issue in global geosciences. The Huozhou complex is situated at the core of the Trans-North China Orogen (TNCO) in the NCC and comprises a considerable number of Palaeoproterozoic granitic gneisses, providing valuable insights into the tectonic evolution of the TNCO. In this study, comprehensive field geological surveys, petrology, chronology, geochemistry, and Hf isotope analysis were conducted to investigate the genesis and tectonic context of the Xingtangsi and Zhengnangou granitic gneisses and elucidate the TNCO's tectonic evolution. The Xingtangsi granite gneiss yielded a magmatic zircon age of 2495±34 Ma, implying its Palaeoproterozoic or Archean origin, as previously suggested. Its protolith was I-type peraluminous granite, primarily generated through the partial melting of pre-existing continental crust materials with a small quantity of mantle-derived magma. The Zhengnangou granitic gneiss's protolith was A-type granite, and its magmatic zircon age was 2,190±11 Ma, indicating its Palaeoproterozoic origin rather than Archean. TDM1(Ma) for the Zhengnangou granitic gneiss ranged from 2,424 to 2,498 Ma, TDM2(Ma) varied from 2563 to 2684 Ma, and the εHf(t) value ranged from 1.3 to 3.3. These results suggest that it was primarily derived from newly formed crustal materials without any mantle-derived addition. Integrating our data with the literature, the ∼2.5 Ga magmatic activity in the Huozhou area may have formed in the tectonic setting of the continental arc, and ∼2.2 Ga A-type granite may have formed in a post-collisional extensional environment. [ABSTRACT FROM AUTHOR]

The Central Asian Orogenic Belt (CAOB) is the world's largest accretionary orogenic belt, and its formation is related to the closure of the Paleo-Asian Ocean (PAO). However, the closure time and style of the PAO remain controversial. To address these issues, this paper presents zircon U-Pb dating, whole-rock geochemistry and zircon Lu-Hf isotope analyses of the volcanic rocks in the Faku-Kaiyuan area on the northern margin of the North China Craton. The results show that the Bachagou andesites formed in the Early Permian (287 ± 2 Ma), while the Chaijialing andesites and dacites formed in the Late Permian (253.3 ± 3.7 Ma) and Middle Triassic (244.3 ± 1.3 Ma), respectively. The Bachagou andesites and Chaijialing andesites are enriched in LILEs and LREEs and depleted in HFSEs and HREEs, indicating that they formed in the active continental margins. The Chaijialing dacites show similar geochemical signatures to adakite and formed in a syn-collisional setting. Geochemistry and isotopic analysis indicates that the Bachagou andesites were derived from a partial melting of the mantle wedge that was metasomatized by subduction fluids. The Chaijialing andesites were generated from a metasomatized mantle by slab-derived and sediment fluids. The Chaijialing dacites formed by a partial melting of thickened lower crust. Combined with previous research results, we can conclude that the Eastern PAO closed by a scissor-like movement from west to east during the Late Permian–Middle Triassic. [ABSTRACT FROM AUTHOR]