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New LA–ICP–MS zircon U–Pb geochronology, whole‐rock major and trace element geochemistry data, and petrographic observations are presented for three granitic dykes in the Changlingzi area of NE China. These data provide precise age and petrogenesis information with respect to the late Palaeozoic–Mesozoic intrusions in the area, which further constrain the geodynamic evolution of the southern Great Xing'an Range. Our zircon U–Pb data denote that the felsic dykes were emplaced during the Late Permian (~254 Ma) and Late Jurassic (143–142 Ma). Geochemically, the Late Permian monzonite porphyries are characterized by high Al2O3 (16.52–16.92 wt%) and Sr (490–579 ppm) contents and low Yb (0.52–0.57 ppm), Y (5.7–6.3 ppm), and heavy rare earth element (HREE) contents, which indicate an adakitic affinity. The Late Jurassic felsic dykes are characterized by high FeOt/MgO (8.2–11.9) and Ga/Al (3.3–3.8) ratios, high zircon saturation temperatures (888–929°C), and remarkable negative Eu (Eu/Eu* = 0.25–0.42) anomalies, indicating they are akin to A‐type granites. The Late Permian adakitic magma resulted from the partial melting of thickened lower crust, and was formed during collisional orogenesis related to subduction of Palaeo‐Asian Ocean crust. The Late Jurassic A‐type magmas were probably generated by the partial melting of amphibolite‐facies lower crustal materials. The melting occurred in response to the upwelling of asthenospheric material caused by collapse of thickened crust, due to gravitational instability during closure of the Mongol–Okhotsk Ocean. Subsequently, the latest stage of magmatic activity in this area and elsewhere in NE China was controlled mainly by subduction of Palaeo‐Pacific Ocean crust. [ABSTRACT FROM AUTHOR]

Herein, new zircon U–Pb ages, whole‐rock major and trace element geochemistry, and Hf isotopes are presented for four Mesozoic granitic rock samples within the Qingchengzi district, eastern China. These data provide precise age and petrogenesis information with respect to the Mesozoic intrusions in the Qingchengzi district, which further constrain the initial decratonization process of the eastern North China Craton (NCC). The zircon U–Pb data reveal that these granitoids are emplaced in the following two stages: Triassic (243–220 Ma) and Middle Jurassic (∼164 Ma). These Mesozoic rocks (lithology: syenogranite, monzogranite, and biotite granite) contain high concentrations of silica (68.94–77.07 wt.%) and total alkali (7.35–9.71 wt.%) together with low concentrations of MgO (0.07–0.98 wt.%), total Fe2O3 (0.81–2.92 wt.%), and CaO (0.17–1.80 wt.%), and they are characterized by an enrichment of large‐ion lithophile elements (LILEs; e.g., Rb, Cs, and K) and light rare earth elements (LREEs) in addition to depletion of high‐field‐strength elements (HFSEs; e.g., Nb, Ta, and Ti) and heavy rare earth elements (HREEs), indicating that these Mesozoic rocks are similar to I‐type granitoids. The εHf(t) values of the magmatic zircons in these granitoids range from −18.7 to −11.4. Such geochemical characteristics indicate that these granitoid formations were generated by the partial melting of the ancient lower crustal material. However, the occurrence of mafic microgranular enclaves in the Shuangdinggou monzogranite implies the mixing of the mantle‐derived magmas. Combined with the results of the previous research, these new data indicate that initial decratonization of the eastern NCC occurred during the Triassic period in response to the collision and amalgamation of the Yangtze Craton and NCC. During the Jurassic, the dynamic mechanism of lithospheric thinning was overprinted owing to the subduction of the Paleo‐Pacific Plate. Furthermore, cratonic destruction reached its peak during the Early Cretaceous, which could be related to the asthenospheric upwelling induced by the rollback of the subducting oceanic slab. [ABSTRACT FROM AUTHOR]

• Ore-forming fluids of stratiform mineralization belong to a NaCl-H 2 O system. • Those of vein-type mineralization are attributed to a NaCl-H 2 O-CO 2 system. • Ore-forming materials of vein-type mineralization were partly from stratiform ores. • Paleoproterozoic stratiform mineralization is typical of SEDEX-type deposits. • Vein-type mineralization represents a moderate-temperature hydrothermal deposit. The Qingchengzi Pb–Zn deposit is located in the northeastern Jiao–Liao–Ji Belt (JLJB), North China Craton (NCC). Field observation and age dating indicate that the deposit was formed from Paleoproterozoic sedimentary exhalative (SEDEX) stratiform mineralization overprinted by Late Triassic hydrothermal vein-type mineralization. Five types of fluid inclusions (FIs) are identified in the quartz grains, based on petrography and laser Raman spectroscopy: liquid-rich two-phase (type 1), vapor-rich two-phase (type 2), CO 2 -bearing (types 3a and 3b), and CO 2 -pure (type 4). Quartz from the SEDEX stratiform ores contains only type 1 FIs, and hydrogen-oxygen isotopic compositions indicate that the ore-forming fluids were magmatic water-derived. The ore-forming fluids were likely of medium-temperatures and low-salinity, and belonged to a NaCl–H 2 O hydrothermal system. Quartz from the vein-types contains all five types of FIs, and the ore-forming fluids may have belonged to a medium-temperature, low-salinity NaCl–H 2 O–CO 2 hydrothermal system. Hydrogen-oxygen isotopes indicate that the vein-type ore-forming fluids were derived from magmatic-meteoric mixed source. Rare-earth element (REE) and sulfur-lead isotopic compositions indicate that ore-forming materials of the SEDEX stratiform mineralization were derived from the wall-rocks and magma, wheres those of the vein-type mineralization were derived from Late Triassic granitic magma, wall-rocks, and the Paleoproterozoic SEDEX ores. Based on field geological and geochronological data, we propose the following regional metallogenic model: (1) SEDEX mineralization occurred during the Paleoproterozoic post-collisional extension in the JLJB; (2) vein-type mineralization was generated by the north-dipping subduction of the Yangtze Craton beneath the NCC, which led to continent-continent collision and slab break-off in the Late Triassic. [ABSTRACT FROM AUTHOR]