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The Khanka Massif forms the easternmost part of the Central Asian Orogenic Belt (CAOB) and represents an ideal location for examination of the timing and processes involved in the transition from the Palaeo-Asian to Palaeo-Pacific Ocean tectonic systems. However, it is obstructed because the late Palaeozoic tectonic attributes of the eastern margin of this massif remain unclear. In this paper, we provide zircon U-Pb ages and Hf isotopic, as well as the whole-rock Sr-Nd-Pb-Hf isotopic data for Permian granitic and volcanic rocks within the eastern margin of the Khanka Massif, with the aim of exploring the petrogenesis and their geodynamics significance. These data suggest that the Permian magmatism within the eastern margin of the Khanka Massif, composed of monzogranites and rhyolites, can be split into two stages; i.e. middle (ca. 264 to ca. 263 Ma) and late (ca. 252 Ma) Permian. The highly fractionated middle Permian monzogranites are formed in an N-S extensional setting and represent the magmatic response to the amalgamation of the Khanka and Jiamusi massifs. Middle-late Permian rhyolites with decoupled Nd-Hf isotopic compositions were derived from partial melting of metasedimentary crustal rocks. Their moderate-high zircon saturation temperatures (796–817°C) are thought to represent the involvement of ridge subduction of the Palaeo-Asian Ocean beneath the western margin of the Khanka Massif. Our findings further reinforce the existence of the ridge subduction of the Palaeo-Asian Ocean at the western margin of Khanka Massif in the Permian, while excluding the possibility of Permian Palaeo-Pacific oceanic plate subduction occurred beneath the eastern margin of the Khanka Massif in the Permian. [ABSTRACT FROM AUTHOR]

When the Paleo‐Asian Ocean closed and the Paleo‐Pacific subduction started in NE China remains controversial. To constrain these key issues, we carried out zircon U‐Pb‐Hf isotopic and whole‐rock geochemical studies of Early Mesozoic igneous rocks in central southern Jilin Province, NE China. Early Mesozoic igneous rocks in region were formed at three stages: the middle Triassic (246 Ma), the late Triassic (219–220 Ma), and the early Jurassic (172–194 Ma). Middle Triassic trachyandesites in southern Jilin Province were solely generated through partial melting of ancient lower crust of the North China Craton (NCC), implying ongoing southward subduction of Paleo‐Asian Ocean Plate beneath the NCC at this time. Late Triassic trachyandesites in southern Jilin Province were derived from the magma mixing/mingling of the NCC lithospheric mantle and juvenile eastern Central Asian Orogenic Belt crustal sources. Late Triassic hornblende gabbros in central Jilin Province were derived from depleted lithospheric mantle previously metasomatized by subduction‐related fluids. Coeval adakitic granodiorites were likely produced through the partial melting of thickened juvenile lower crust. Spatially, these rocks occurred on both sides of the Solonker‐Xra‐Moron‐Changchun Suture Zone and record N–S directed extension accompanied by the final closure of the Paleo‐Asian Ocean. Early Jurassic andesites were produced through mixing/mingling between partial melts derived from eastern Central Asian Orogenic Belt lithospheric mantle and ancient NCC crust. In contrast, Early Jurassic felsic rocks, including A‐type granites, were derived from the partial melting of Neoproterozoic accreted lower crust, jointly implying an extensional setting as the result of the initial subduction from Paleo‐Pacific Plate at this time. Key Points: Three magmatism stages are recognized in central southern Jilin Province, NE ChinaMiddle–Late Triassic rocks record the subduction and termination of Paleo‐Asian Ocean tectonic regimeEarly Jurassic rocks record the onset of the Paleo‐Pacific tectonic regime [ABSTRACT FROM AUTHOR]