Late Mesozoic volcanic rocks are widespread in the Great Xing’an Range (GXR), Northeast (NE) China. However, details of the tectono-magmatic evolution during the Late Mesozoic are poorly understood. In this paper, new zircon U–Pb, Lu–Hf, and whole-rock geochemical data from Late Mesozoic volcanics in the southern GXR, are used to further constrain the tectono-magmatic evolution of the region. Late Mesozoic magmatism in the GXR, eastern Mongolia and southern Transbaikalia occurred during the Early Cretaceous (120–140 Ma) and Late Jurassic (150–163 Ma) periods. Late Jurassic trachyandesites-trachytes show a low rare earth element and moderate light rare earth element (LREE) enrichment with no Eu anomalies. Early Cretaceous trachytes are characterized by an LREE enrichment and negative Eu anomalies. Contemporaneous rhyolites exhibit a significant LREE enrichment, A–type granitoid affinity, and pronounced negative Eu anomalies. Different negative Nb, Ta, and Ti anomalies, and positive zircon ε_Hf(t) values, indicate that the ~160 Ma trachyandesites-trachytes are derived from partial melting of the lithospheric mantle that was metasomatized by subduction-related fluids. The ~125 Ma trachytes and rhyolites were possibly generated by partial melting of the accreted Meso-Neoproterozoic lower crust. New and previously published geochemical, isotopic and geochronological data from the southern GXR, eastern Mongolia and East-Transbaikalia, suggest that Late Jurassic–Early Cretaceous volcanism in the southern GXR occurred during the post-collisional extension after the closure of the Mongol–Okhotsk Ocean.

The Linxi Formation is widely deposited in eastern Inner Mongolia (NE China), especially along northern parts of the Solonker-Xar Moron Suture (SXMS) in the eastern Central Asian Orogenic Belt, yet its depositional age and provenance remain ambiguous. We studied the petrography, geochronology, and Hf isotopes of two sandstone samples from this formation, and estimated the depositional age and the provenance of the Linxi Formation, and further constrained the evolution of the Paleo-Asian Ocean (PAO). Based on detailed field observations and measurements, we. Zircons from rocks of the Linxi Formation are mainly composed of detrital zircons of magmatic origin. The determined ages of detrital zircons range from 233 ± 2 Ma to 1365 ± 14 Ma, and indicate that the provenance of the Linxi Formation experienced at least four tectonic-thermal events between 1365 and 233 Ma: Neoproterozoic (ca. 1365–543 Ma), Early Palaeozoic (ca. 512–426 Ma), Late Palaeozoic (ca. 418–251 Ma), and Early Mesozoic (ca. 249–233 Ma). The youngest detrital zircon, with a U-Pb age of 233 ± 2 Ma, defines the maximum depositional age of the Linxi Formation. The ε_Hf (t) values of dated zircons from the sandstone samples have a large range (−7.8–15.0). The four dominant age groups and the range in ε_Hf (t) values are widely found in the Xing’an Block and Songnen-Zhangguangcai Range, which imply that the source of the Linxi Formation had an affinity with northeastern China. These data together with previous geochronological data (from west to east along the SXMS) on the crystallization and depositional ages of detrital zircon suggest that the Linxi Formation was deposited in different tectonic settings: convergent, collisional, and extensional. This study provides further evidence and constraints for the non-synchronous closure of the PAO.

The southern Great Xing’an Range is located in the eastern Central Asian Orogenic Belt, where voluminous igneous rocks developed during the Late Mesozoic period. The east slope of the southern Great Xing’an Range has been the topic of numerous debates on the level of influence of the Mongol-Okhotsk and the Paleo-Pacific regimes in the Late Mesozoic period. Therefore, this area is a suitable region in which to study the temporal changes in magma sources and tectono-magmatic evolution. In this paper, whole-rock geochemical data, zircon U-Pb geochronology, and zircon Hf isotope studies were carried out on the granitoids in the east slope area of the southern Great Xing’an Range. LA-ICP-MS zircon U-Pb dating revealed the ages of four granitoid samples: 135.0 ± 0.6 Ma, 130.7 ± 1.4 Ma, 130.4 ± 1.0 Ma, and 127.6 ± 0.8 Ma, respectively. The Hf isotope values ¹⁷⁶Hf/¹⁷⁷Hf = 0.282751–0.283015, ε_Hf (t) = +2.0~+11.5, and T_2DM = 583~1442 Ma suggest that the magma was generated by partial melting of Meso- and Neoproterozoic accreted and thickened low crust. The whole-rock geochemical data implied that these granitoids are A-type granite and their formation is closely linked to the subduction of the Paleo-Pacific Ocean plate. These geochemical, isotopic, and geochronological data suggest that the Early Cretaceous magmatism in the east slope area of the southern Great Xing’an Range formed in an extensional back-arc tectonic setting associated with the slab roll-back of the Paleo-Pacific plate subduction.

基于四种超声悬浮液模型Urick, Urick-Ament, HT, Mcclements分析了Scholte波在两相流体与多孔介质固体界面处的传播特性. 结合各模型的复波数表达式建立含泥沙流体-多孔介质固体界面波特征方程, 分析了Scholte波速与两相流体积含量、粒径等介质属性的关系. 通过仿真实验获得界面波信号, 运用时延估计获得Scholte波速与泥沙含量、粒径的关系, 发现所得的波速与Urick-Ament和HT理论有相对好的一致性.

Frequent geological hazards such as landslides and rockfalls, intensified by human activities and extreme rainfall, highlight the urgent need for rapid, accurate, and interpretable susceptibility assessment. However, existing methods often struggle with insufficient characterization of spatial heterogeneity, fragmented spatial structures, and limited mechanistic interpretability. To overcome these challenges, this study proposes an intelligent landslide susceptibility assessment framework based on the Swin-UNet architecture, which combines the window-based self-attention mechanism of the Swin Transformer with the encoder–decoder structure of U-Net. Eleven conditioning factors derived from remote sensing data were used to characterize the influencing conditions. Comprehensive experiments conducted in Changbai County, Jilin Province, China, demonstrate that the proposed Swin-UNet framework outperforms traditional models, including the information value method and the standard U-Net. It achieves a maximum overall accuracy of 99.87% and consistently yields higher AUROC, AUPRC, F1-score, and IoU metrics. The generated susceptibility maps exhibit enhanced spatial continuity, improved geomorphological coherence, and greater interpretability of contributing factors. These results confirm the robustness and generalizability of the proposed framework and highlight its potential as a powerful and interpretable tool for large-scale geological hazard assessment, providing a solid technical foundation for refined disaster prevention and mitigation strategies.