At least 13 active fault zones have developed in the Ya’an-Linzhi section of the Sichuan-Tibet transport corridor, and there have been undergone 17 M_S ≥ 7.0 earthquakes, the largest earthquake is 1950 Chayu M_S 8.5 earthquake, which has very strong seismic activity. Therefore, carrying out engineering construction in the Sichuan-Tibet transport corridor is a huge challenge for geological technological personnel. To determining the spatial geometric distribution, activity of active faults and geological safety risk in the Sichuan-Tibet transport corridor. Based on remote sensing images, ground surveys, and chronological tests, as well as the deep geophysical and current GPS data, we investigated the geometry, segmentation, and paleoearthquake history of five major active fault zones in the Ya’an-Linzhi section of the Sichuan-Tibet transport corridor, namely the Xianshuihe, Litang, Batang, Jiali-Chayu and Lulang-Yigong. The five major fault zones are all Holocene active faults, which contain strike-slip components as well as thrust or normal fault components, and contain multiple branch faults. The Selaha-Kangding segment of the Xianshuihe fault zone, the Maoyaba and Litang segment of the Litang fault zone, the middle segment (Yigong-Tongmai-Bomi) of Jiali-Chayu fault zone and Lulang-Yigong fault zone have the risk of experiencing strong earthquakes in the future, with a high possibility of the occurrence of M_S ≥ 7.0 earthquakes. The Jinsha River and the Palong-Zangbu River, which is a high-risk area for geological hazard chain risk in the Ya’an-Linzhi section of the Sichuan-Tibet transport corridor. Construction and safe operation Ya’an-Linzhi section of the Sichuan-Tibet transport corridor, need strengthen analysis the current crustal deformation, stress distribution and fault activity patterns, clarify active faults relationship with large earthquakes, and determine the potential maximum magnitude, epicenters, and risk range. This study provides basic data for understanding the activity, seismicity, and tectonic deformation patterns of the regional faults in the Sichuan-Tibet transport corridor.

The analysis of hydrochemical characteristics and influencing factors of surface river on plateau is helpful to study water hydrological cycle and environmental evolution, which can scientifically guide rational development and utilization of water resources and planning of ecological environment protection. With the expansion and diversification of human activities, the quality of surface rivers will be more directly affected. Therefore, it is of great significance to pay attention to the hydrochemical characteristics of plateau surface rivers and the influence of human activities on their circulation and evolution. In this study, surface water in the Duoqu basin of Jinsha River located in Hengduan mountain region of Eastern Tibet was selected as the representative case. Twenty-three groups of surface water samples were collected to analyze the hydrochemical characteristics and ion sources based on correlation analysis, piper trigram, gibbs model, hydrogen and oxygen isotopic techniques. The results suggest the following: (1) The pH showed slight alkalinity with the value ranged from 7.25 to 8.62. Ca²⁺, Mg²⁺ and HCO₃^- were the main cations and anions. HCO₃-Ca and HCO₃-Ca·Mg were the primary hydrochemical types for the surface water of Duoqu River. The correlation analysis showed that TDS had the most significant correlation with Ca²⁺, Mg²⁺ and HCO₃^-. Analysis on hydrogen and oxygen isotopes indicated that the surface rivers were mainly recharged by atmospheric precipitation and glacial melt water in this study area. (2) The surface water had a certain reverse cation alternating adsorption, and surface water ions were mainly derived from rock weathering, mainly controlled by weathering and dissolution of carbonates, and secondly by silicates and sodium rocks. (3) The influence of human activities was weak, while the development of cinnabar minerals had a certain impact on the hydrochemistry characteristics, which was the main factor for causing the increase of SO₄^2-. The densely populated county towns and temples with frequent incense burning activities may cause some anomalies of surface water quality. At present, the Duoqu River watershed had gone through a certain influence of mineral exploitation, so the hydrological cycle and river ecoenvironment at watershed scale will still bound to be change. The results could provide basic support for better understanding water balance evolution as well as the ecological protection of Duoqu River watershed.

The reconstruction of paleohydrology, especially paleosalinity, is an important component of paleoenvironmental research. Researches on the modern characteristics of lake water chemistry and the relationship between lake salinity and hydrochemistry are the basis of paleoenvironment reconstruction. The modern hydrochemical characteristics and the relationship between ion composition and salinity of modern lakes are the basis of paleosalinity reconstruction. In this study, hydrochemical analysis of 21 lakes in the Badain Jaran Desert (BJD) was carried out. The relationships between the Sr/Ca and Mg/Ca ratios and total dissolved solids (TDS) were analyzed. The results show that Na⁺, K⁺, Cl⁻ and SO₄²⁻ have high positive correlations with TDS, and Mg²⁺, Sr²⁺, CO₃²⁻ and HCO₃⁻ have lower correlations with TDS. The Sr/Ca and Mg/Ca ratios do not increase linearly with TDS. Hydrochemical analysis indicates that the studied lakes are in the carbonate precipitation stage and that evaporation is the main factor controlling lake evolution in the BJD. The relationships between the Mg/Ca and Sr/Ca ratios and TDS are mainly influenced by lake evolution stage and the hydrochemical types of the lakes. On the basis of comprehensive previous studies, the factors affecting lake evolution, the Mg and Sr partition coefficients and other hydrochemical parameters that change with lake evolution all affect the relationship between chemical composition and salinity. To reconstruct paleosalinity more accurately, more detailed research on the modern hydrochemical characteristics of lakes and the relationship between the element ratios of carbonates and water salinity should be carried out.

Oyster is a bivalve mollusk widely distributed in estuarine and shallow sea environments. Its growth and burial process is a carbon sequestration and storage process. Oyster shell may stop growing due to suffer from freeze shock during the winter season within a temperate climate, therefore, in order to study the carbon sequestration capacity of oysters we need to know the water temperature at which the shell suffer from winter freeze shock. This study examines δ¹⁸O profiles across consecutive micro-growth layers found in three modern Pacific oyster shells from the northwest coast of Bohai Bay. A total of 165 oxygen isotope values from sequential samples of their left shells showed periodically varying values, and the variation fluctuation of oxygen isotope values was 4.97‰ on average. According to the variation range of the oxygen isotope value of the shell, combined with the sea surface temperature and the sea surface salinity data of the water in which the oysters grew, the water temperature that suffer from winter freeze shock and stops or retards the growth of Pacific oysters in Bohai Bay is about 8.3°C, and the corresponding period is from December to March of the following year. The calcification time of oysters within one year is nearly a month longer than previously thought, therefore, its carbon sink potential is also improved.

Glaciers, as “solid reservoirs”, are precious resources in arid areas. The study of glaciers is of great significance to the sustainable development and management of agriculture and the economy in northern Xinjiang. The area of glacier distribution on the 1963 topographic map data, 1975 MSS data, 2000 ETM data, 2008 CBERS-2 data, 2014 and 2018 ETM+ were collected as secondary data. According to the remote sensing survey, the glacier areas in Northern Xinjiang are identified during 1963-2018. Based on the evolution of glacier area in the past 55 years, and using two scenarios, the average annual decrease area of a region during the whole 1963-2018 and the period with the minimum reduction area, the glacier areas of Southern Tianshan Mountains, Western Tianshan Mountains, Eastern Tianshan Mountains, the Sawuer Mountains and Altai Mountains in Northern Xinjiang, and the whole northern Xinjiang in 2030, 2040, 2050, and 2100 are examined and predicted. In 2100, the glacier area in Northern Xinjiang may decrease by 43%-59%.

Water erosion is a serious problem that leads to soil degradation, loss, and the destruction of structures. Assessing the risk of erosion and determining the affected areas has become crucial in order to understand the main factors influencing its evolution and to minimize its impacts. This study focuses on evaluating the risk of erosion in the Assif el mal watershed, which is located in the High Atlas Mountains. The Erosion Potential Model (EPM) is used to estimate soil losses depending on various parameters such as lithology, hydrology, topography, and morphometry. Geographic information systems and remote sensing techniques are employed to map areas with high erosive potential and their relationship with the distribution of factors involved. Different digital elevation models are also used in this study to highlight the impact of data quality on the accuracy of the results. The findings reveal that approximately 59% of the total area in the Assif el mal basin has low to very low potential for soil losses, while 22% is moderately affected and 19.9% is at high to very high risk. It is therefore crucial to implement soil conservation measures to mitigate and prevent erosion risks.

The ultramafic massif of Feragen, which belongs to the eastern ophiolitic belt of Norway, has abundant amounts of chromite ores. Recent studies have revealed a complex melt evolution in a supra-subduction zone (SSZ) environment. This study presents new whole-rock major element, trace element, and platinum-group element chemistry to evaluate their petrogenesis and tectonic evolution. Harzburgites have high CaO, Al₂O₃, TiO₂, MgO, and REE contents corresponding to abyssal peridotites, whereas dunites have low CaO, Al₂O₃, TiO₂, MgO, and REE contents corresponding to SSZ peridotites. The Cr# and TiO₂ of chromian spinels in the harzburgites suggest as much as about 15%-20% melting and the dunites are more depleted with > 40% melting. The harzburgites and the dunites and high-Cr chromitites represent, respectively, the products of low-degree partial melting in a back-arc setting, and the products of melt-rock interaction in a SSZ environment. The calculated ƒO₂ values for dunites and high-Cr chromitites (−0.17 - +0.23 and +2.78 - +5.65, respectively and generally above the FMQ buffer) are also consistent with the interaction between back-arc ophiolites with oxidized boninitic melts in a SSZ setting.

Elemental analysis, nuclear magnetic resonance carbon spectroscopy (¹³C-NMR), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) experiments were carried out to determine the existence of aromatic structure, heteroatom structure and fat structure in coal. MS (materials studio) software was used to optimize and construct a 3D molecular structure model of coal. A method for establishing a coal molecular structure model was formed, which was “determination of key structures in coal, construction of planar molecular structure model, and optimization of three-dimensional molecular structure model”. The structural differences were compared and analyzed. The results show that with the increase of coal rank, the dehydrogenation of cycloalkanes in coal is continuously enhanced, and the content of heteroatoms in the aromatic ring decreases. The heteroatoms and branch chains in the coal are reduced, and the structure is more orderly and tight. The stability of the structure is determined by the π-π interaction between the aromatic rings in the nonbonding energy E_N. Key Stretching Energy The size of E_B determines how tight the structure is. The research results provide a method and reference for the study of the molecular structure of medium and high coal ranks.

Xiarihamu deposit is the only super-large Ni-Co deposit found in East Kunlun orogenic belt (EKOB) until present. Shitoukengde (STKD) intrusion is considered to have the potential to become a large Ni-Co deposit in East Kunlun. In order to discuss the metallogenic potential, this study present petrographical, geochemical data, and zircon U-Pb dating for the STKD intrusion. The STKD intrusion is hosted within mafic-ultramafic rocks which contain peridotite, pyroxenite and gabbro, and mainly intruded into the marble of the Paleoproterozoic Jinshuikou Group. Harzburgite and orthopyroxenite are the main country rocks for the Cu-Ni sulfide mineralization. Combine with the positive ε_Hf(t) values (+1.1 to +8.6) of zircons, the enrichment of LILEs, depletion of HFSEs, and lower Ce/Pb ratios of whole rocks indicate that the parental magma was originated from the depleted asthenospheric mantle and experienced 5%-15% crustal contamination. Troctolite formed during the Early Devonian and it has weighted mean ²⁰⁶Pb/²³⁸U age of 412 Ma. Regional background information has indicated that the post-collisional extension setting has already existed during the Early Devonian, leading to the formation of STKD intrusion and Cu-Ni sulfide mineralization. STKD intrusion may have the potential to be one economic Cu-Ni sulfide deposit but seems unlikely to be a super-large one.

Porphyry Cu (Mo-Au) deposit is one of the most important types of copper deposit and usually formed under magmatic arc-related settings, whilst the Mujicun porphyry Cu-Mo deposit in North China Craton uncommonly generated within intra-continental settings. Although previous studies have focused on the age, origin and ore genesis of the Mujicun deposit, the ore-forming age, magma source and tectonic evolution remain controversial. Here, this study targeted rutile (TiO₂) in the ore-hosting diorite porphyry from the Mujicun Cu-Mo deposit to conduct in situ U-Pb dating and trace element composition studies, with major views to determine the timing and magma evolution and to provide new insights into porphyry Cu-Mo metallogeny. Rutile trace element data show flat-like REE patterns characterized by relatively enrichment LREEs and depleted HREEs, which could be identified as magmatic rutile. Rutile U-Pb dating yields lower intercept ages of 139.3-138.4 Ma, interpreted as post magmatic cooling timing below about 500°C, which are consistent or slightly postdate with the published zircon U-Pb ages of diorite porphyry (144.1-141.7 Ma) and skarn (146.2 Ma; 139.9 Ma) as well as the molybdenite Re-Os ages of molybdenum ores (144.8-140.0 Ma). Given that the overlap between the closure temperature of rutile U-Pb system and ore-forming temperature of the Mujicun deposit, this study suggests that the ore-forming ages of the Mujicun deposit can be constrained at 139.3-138.4 Ma, with temporal links to the late large-scale granitic magmatism at 138-126 Ma in the Taihang Orogen. Based on the Mg and Al contents in rutile, the magma of ore-hosting diorite porphyry was suggested to be derived from crust-mantle mixing components. In conjunction with previous studies in Taihang Orogen, this study proposes that the far-field effect and the rollback of the subducting Paleo-Pacific slab triggered lithospheric extension, asthenosphere upwelling, crust-mantle interaction and thermo-mechanical erosion, which jointly facilitated the formation of dioritic magmas during the Early Cretaceous. Subsequently, the dioritic magmas carrying crust-mantle mixing metallic materials were emplaced and precipitated at shallow positions along NNE-trending ore-controlling faults, eventually resulting in the formation of the Mujicun Cu-Mo deposit within an intracontinental extensional setting.

Upper Ordovician-Lower Silurian Wufeng-Longmaxi Formation is the most developed strata of shale gas in southern China. Due to the complex sedimentary environment adjacent to the Kangdian Uplift, the favorable area for organic-rich shale development is still undetermined. The authors, therefore, focus on the mechanism of accumulation of organic matter and the characterization of the sedimentary environment of the Wufeng-Longmaxi Shales to have a more complete understanding and new discovering of organic matter enrichment and favorable area in the marginal region around Sichuan Basin. Multiple methods were applied in this study, including thin section identification, scanning electron microscopy (SEM) observations and X-ray diffraction (XRD), and elemental analysis on outcrop samples. Five lithofacies have been defined according to the mineralogical and petrological analyses, including mudstone, bioclastic limestone, silty shale, dolomitic shale, and carbonaceous siliceous shale. The paleo-environments have been reconstructed and the organic enrichment mechanism has been identified as a reduced environment and high productivity. The Wufeng period is generally a suboxic environment and the early Longmaxi period is a reducing environment based on geochemical characterization. High dolomite content in the study area is accompanied by high TOC, which may potentially indicate the restricted anoxic environment formed by biological flourishing in shallower water. And for the area close to the Kangdian Uplift, the shale gas generation capability is comparatively favorable. The geochemical parameters implied that new favorable areas for shale gas exploration could be targeted, and more shale gas resources in the mountainbasin transitional zone might be identified in the future.

The Hongqiling large nickel-copper-cobalt deposit (hereafter referred to as the Hongqiling deposit), a typical mafic-ultramafic copper-nickel deposit in China, boasts proven Ni (Ni) resources of approximately 22×10⁴ t, associated copper resources of 2×10⁴ t, and associated cobalt (Co) resources of 0.5×10⁴ t, with Ni reserves ranking 10^th among China’s magmatic nickel deposits. Geotectonically, the Hongqiling deposit is situated in the superimposed zone between the Xing’an-Mongolian orogenic belt and the circum-Western Pacific’s active continental margin belt. Its ore-bearing plutons occur within the metamorphic rocks of the Ordovician Hulan Group, with the emplacement of plutons and the locations of orebodies governed by the deep-seated Huifahe fault and its secondary NW-trending Fujia-Hejiagou-Beixinglong-Changsheng fault zone. In the deposit, the rock assemblages of ore-bearing plutons predominantly encompass gabbro - pyroxenite - olivine pyroxenite - pyroxene peridotite (pluton No. 1) and noriteorthopyroxenite-harzburgite (pluton No. 7), with ore-bearing lithofacies consisting primarily of olivine pyroxenite and pyroxenite facies. The Hongqiling deposit hosts stratoid, overhanging lentoid, veined, and pure-sulfide veined orebodies. Its ores principally contain metallic minerals including pyrrhotite, pentlandite, chalcopyrite, violarite, and pyrite. Despite unidentified magma sources of ore-bearing mafic-ultramafic rocks, it is roughly accepted that the magmatic evolution in the Hongqiling deposit primarily involved fractional crystallization and crustal contamination. The ore-forming materials were primarily derived from the upper mantle, mixed with minor crustal materials. The ore-bearing mafic-ultramafic rocks in the deposit, primarily emplaced during the Indosinian (208-239 Ma), were formed in an intense extension setting followed by the collisional orogeny between the North China Plate and the Songnen-Zhangguangcai Range Block during the Middle-Late Triassic. From the perspective of the metallogenic geological setting, surrounding rocks, ore-controlling structures, and rock assemblages, this study identified one favorable condition and seven significant indicators for prospecting for Hongqiling-type nickel deposits and developed a prospecting model of the Hongqiling deposit. These serve as valuable references for exploring similar nickel deposits in the region, as well as the deep parts and margins of the Hongqiling deposit.