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Digital geological survey methods have become supplementary approaches for traditional geological survey in the last two decades. In this paper, the Unmanned Aerial Vehicle (UAV)‐based photogrammetry technology is used to obtain the 3D point cloud model of rock outcrops. The clustering algorithm is used to automatically identify the rock discontinuity parameters. However, the obtained 3D point cloud model with high resolution often has a huge point data which usually poses a great challenge to the computational efficiency of the automatic identification. In fact, too‐dense point cloud data may not be necessary for cases when the rock mass is relatively intact. The optimal point cloud resolution, which balances the accuracy and efficiency, depends on the degrees of fragmentation of the rock mass under investigation. For a model with the same resolution, large‐size discontinuities may have quite a few redundant point cloud data that are of little use to improve the identification accuracy whereas small‐size discontinuities may not be properly identified due to insufficient number of data points. In this paper, the influence of the degree of fragmentation of rock mass on the identified results was investigated. The uniform grid method was adopted to sparse the 3D point cloud model. The optimal point cloud resolution for different discontinuities was suggested. The applicability and feasibility of the proposed approach were verified via three illustrative examples of typical rock slopes. [ABSTRACT FROM AUTHOR]

The source of oil and gas in the Tarim Basin's platform has always been controversial. The Lower Cambrian Yurtusi Formation and the Xidashan Formation–Xishanbulak Formation argillaceous source rocks are an important set of oil source series in the basin. Based on the principle of conservation of matter, this paper calculates the hydrocarbon expulsion amount of the source rock. Using a phase state hydrocarbon expulsion amount characterization model, the paper reconstructs the evolution process of the hydrocarbon expulsion phase state of the source rock. According to the characterization model of hydrocarbon expulsion dynamics, the relative contribution of each force to hydrocarbon expulsion is evaluated. The hydrocarbon expulsion geologic model of argillaceous source rocks in the Lower Cambrian in the Tarim Basin is established. The results show that this set of source rocks can serve the main source rocks in the basin. The hydrocarbon expulsion of the Lower Cambrian argillaceous source rocks in the Tarim Basin can be divided into three stages. In the first stage, the hydrocarbon expulsion phase is dominated by the water‐soluble and diffusion phases. The conversion of clay minerals into dehydration and diffusion forces is the main driving force for the hydrocarbon expulsion. In the second stage, the oil and gas expulsion present the characteristics of multiphase and multidynamic coexistence. In the third stage, the phase state of oil and gas expulsion is mainly free phase. The capillary force difference and the thermal expansion force of the fluid rock are the main driving forces for oil and gas expulsion. The research results of this paper can deepen the understanding of the hydrocarbon expulsion mechanism of the set of source rocks, and then guide oil and gas exploration. [ABSTRACT FROM AUTHOR]

Shale reservoir has strong heterogeneity in mineral composition and oil content even at a short distance in the same interval. To better understand the accumulation mechanism of shale oil and hydrocarbon migration tendency in the interval, and explore the main influencing factors of distribution. This paper employed various methods, including thin‐section observation, TOC (total organic matter (OM)) analysis, rock pyrolysis, Soxhlet extraction, group component separation, and GC–MS (gas chromatography mass spectrometry) analysis of saturated hydrocarbons. The shale oil samples were collected from an exploratory well in the Songliao Basin, and the distribution and enrichment characteristics of shale oil interlayers were analysed. The results show that the first member of Qingshankou Formation (K2qn1) could be divided into six small layers. From Q1 to Q6, the lithofacies could be divided into three types: high‐frequency laminar shale, massive shale, and bioclastic shale. The lacustrine matrix shale of K2qn1 in Songliao Basin has medium TOC, and high oil contents, OM conversion rate. The TOC ranges from 1.5 to 4.2 wt%, S1 varies between 1.4 and 4 mg/g, S2 falls within the range of 4 to 10.6 mg/g, Tmax ranges from 351 to 497°C, and the OSI varies between 57 and 115.34 mg HC/g rock. The lower part of the K2qn1, Q1–Q4, characterized by high‐frequency laminar shale, contained residual shale oil, while the upper part of the K2qn1, Q5 and Q6, characterized by bioclastic shale and massive mudstone, and are dominated by in‐situ type shale oil. The crude oil in K2qn1 is homologous, and primarily undergoes micro‐migration. The Q5–Q6 section has the highest light oil content, while other regions with notable light components are located in the middle of Q1, the upper sections of Q2, Q3, and Q4.Q1–Q4 are primarily composed of residual shale oil, whereas Q5–Q6 is primarily composed of in‐situ shale oil, and the primary micro‐migration direction of shale oil occurs laterally within Q1–Q4. The lateral migration of each section mainly occurs at the upper part of Q3 and Q4, the lower part of Q1 and Q2, the bottom of Q5, and the interface between Q6 and the second member of Qingshankou formation (K2qn2). The block mudstone retains in‐situ shale oil, especially light hydrocarbons. Within the high‐frequency laminar shale, there is strong horizontal connectivity, and lateral hydrocarbon expulsion serves as the primary mechanism for micro‐migration in Q1–Q4. This paper can provide reference values for K2qn1 Formation shale oil and the migration and differential reservoir formation of medium and high‐maturity matrix shale oil. [ABSTRACT FROM AUTHOR]

Considering the rapid expansion of the economy and the increasing demand for infrastructure development, the scale of the tunnelling is expanding, and tunnel is inevitably excavated under unfavourable geological conditions. Consequently, this brings multitude of risks and challenges to tunnels and tunnelling. This paper summarizes the engineering issues associated with five unfavourable geological conditions: soft soil strata, soft and hard composite strata, spatially variable strata, karst strata and subsea conditions. Various analysis methods for deformation problem of tunnel and tunnelling under these unfavourable geological conditions are discussed. The mechanisms of the progressive failure of tunnel faces and collapses of caves in karst tunnels are also presented, as well as the risk assessments and prevention strategies for karst tunnel and water inrush occurrences of subsea tunnel. Furthermore, the analysis of the response of subsea tunnels to dynamic loads such as wave forces and earthquakes is summarized. Additionally, the analysis and prevention techniques for constructing subsea tunnels in fault zones are also considered. Finally, this paper offers a glimpse into potential research directions for future analysis relevant to the topic discussed, aiming to provide guidance for secure construction and maintenance tunnels under unfavourable geological conditions. [ABSTRACT FROM AUTHOR]

Unlike previous studies, this paper specifically casts light on Middle Eastern and North African (MENA) oil exporters that desperately need to give a strong boost to renewable energy (RE) sources and export rather than uselessly burn their hydrocarbon resources, which support an overwhelming part of their economies. This paper extends the previous research by investigating the impact of oil revenues, innovation, financial development, and governance on renewable energy generation in eight oil‐rich MENA countries over the period 1996–2020 using the three‐stage least squares (3SLS) estimator, which is asymptotically more efficient than the two‐stage least squares (2SLS) employed in the similar‐scoped study of Bellakhal et al. (Energy Economics, 2019, 84, 104541). Furthermore, this study aims to detect structural changes in the econometric relationships between variables depending on a novel test with structural breaks proposed by Karavias and Tzavalis (Computational Statistics & Data Analysis, 2014, 76, 391–407). The main findings indicate that oil rents negatively and significantly affect RE production in MENA oil exporters in general and in non‐GCC countries in particular. While renewable energy production in the GCC countries is positively and significantly affected by oil rents. Innovation‐led RE increases at a greater pace in the GCC countries than in their non‐Gulf counterparts. renewable energy production appears to be positively and significantly affected by financial development and governance in oil‐rich MENA countries. [ABSTRACT FROM AUTHOR]

Challenges brought on by the rapid rate of economic growth include the depletion of natural resources (NAR) and environmental deterioration. Due to its abundant mineral resources and rapid economic growth, China has gained attention from both the developing and developed worlds. Using data from 1970/Q1 to 2020/Q4, this paper evaluates the time‐frequency nexus between CO2 emissions and natural resources, coal consumption, and economic growth. The study employs the Wavelet Local Multiple Correlation (WLMC) to explore this nexus. This approach enhances the capacity to comprehend the fundamental relationships between these indicators at different frequencies. To the best of the investigator' knowledge, this is the first empirical investigation to explore the time‐frequency nexus between natural resource, economic growth, coal use, and CO2 emissions in China, thus filling a gap in the literature. Furthermore, wavelet coherence is employed as a robustness check. The WLMC bivariate cases revealed that economic growth, coal consumption, and natural resources drive CO2 emissions positively at all frequencies, that is, in the short and long‐term, thus leading to environmental degradation. Furthermore, the wavelet coherence results support the outcomes of the WLMC bivariate cases. This study offers significant implications for policy and insights that are supported by the findings. [ABSTRACT FROM AUTHOR]

Differences in the pore and fracture systems of four marcolithotypes (bright，semi‐bright, semi‐dull and dull) in coal reservoirs affect the quality of coalbed methane (CBM) and constrain exploration and development of CBM. In this paper, vitrinite reflectance (RO), maceral composition, proximate analysis, scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), low‐field nuclear magnetic resonance (NMR) and high‐pressure isothermal adsorption experiments and the mathematical method of fractal dimension were carried out on high‐rank coal samples of different marcolithotypes from the Weizhou mining area in the western margin of Ordos Basin. The results show that from bright coal to dull coal, the RO and vitrinite content gradually decrease, while the mineral content and Aad gradually increase. SEM images show that the bright and semi‐bright coals develop open fractures, whereas semi‐dull and dull coals develop closed fractures. According to pore size distribution established by MIP and NMR, the proportion of seepage pores gradually increased from bright coal to dull coal, and MIP fractal dimension of seepage pores (DM2; 2.3352, 2.3532, 2.3755 and 2.4727, respectively) and NMR fractal dimension of seepage pores (DN2; 2.8767, 2.9142, 2.9297 and 2.9981, respectively) show that the structure of the seepage pore is progressively more complex from bright coal to dull coal. In addition, percentage of NMR adsorption pores progressively increases from bright coal to dull coal (64.96%, 76.64%, 82.04% and 89.67%, respectively), but total porosity of bright coal (6.74%) is much greater than that of dull coal (1.34%), which results in that bright coal also has the strongest CH4 adsorption capability (Langmuir volume is 22.898 cm3/g). [ABSTRACT FROM AUTHOR]

Global research on the geological particularities of coal‐accumulating environments and the enrichment patterns of coalbed methane (CBM) is still relatively weak. This paper studies the geological characteristics and coal accumulation patterns of Carboniferous‐Permian coal‐bearing seams in the southern Qinshui Basin. The results show that the coal‐bearing strata in the basin represent the offshore marine and continental intercalated coal seam sediments developed. The southern part of the basin is dominated by lacustrine facies, and the delta front sub‐facies is locally developed. The characteristics of coal accumulation environment in the southern Qinshui Basin are characterized by basement properties, fault networks and coal‐bearing sedimentary facies, which collectively control the spatial and temporal distribution characteristics of the coal‐rich belt. The differences in coal accumulation environment in the southern basin affect the tectonic evolution, the thickness of the coal seam roof and floor and the hydrogeological conditions of the coal‐rich area, which further control the CBM enrichment in the Taiyuan‐Shanxi Formation. The aim of this study is to explore the factors of CBM enrichment and gas control mode, so as to enrich and improve the theory and method of CBM exploration, which will also help identify the appropriate underground geological structure environment for carbon sequestration (CCS), reduce greenhouse gas emissions and effectively respond to the challenge of global warming. [ABSTRACT FROM AUTHOR]

Cobalt is a critical and strategic metal mainly found as associated element in several types of deposits, of which skarn‐type deposits are the major sources. Han‐Xing type skarn iron deposit, having high grade iron ore and associated cobalt, is a typical skarn‐type iron ore in China. But the complete recovery and exploitation of cobalt are restricted because of the lower grade of related cobalt and the dearth of prior research on its occurrence condition and enrichment mechanism. In this paper, pyrite from five typical ore deposits in the Han‐Xing area was studied by using electron probe microanalysis (EPMA) and laser‐ablation inductively‐coupled‐plasma mass‐spectrometry (LA–ICP–MS) techniques to decipher the occurrence state and enrichment mechanism of associated cobalt in skarn‐type iron deposits. The results show that Co2+ replaces Fe2+ in pyrite through isomorphism. The distribution of cobalt in pyrite from different deposits varies greatly, that is, in the Xishimen iron deposit, the cobalt content is comparatively enriched in the pyrite's core. In contrast, in other deposits, the cobalt content is concentrated in the pyrite's rims, where it can be up to 1000 times higher than in the core. The cobalt mineralization in Han‐Xing area can be divided into several stages. The sulphur element of sulphide is mainly derived from evaporite, while cobalt mineralization occurred in the early stage with pyrite formation or in the late stage by metasomatism/cementation of Co‐rich ore‐forming fluid. The magma assimilated with the Ordovician evaporite not only promoted iron mineralization, but also became the main controlling factor for cobalt enrichment. [ABSTRACT FROM AUTHOR]

The Neotethyan Sanandaj–Sirjan Zone of western Iran has recorded major magmatic activities due to its continental arc tectonic setting during the Mesozoic. The Varcheh mafic intrusions were less‐studied plutons in the northern Sanandaj–Sirjan Zone (SSZ). Field evidence, petrography, geochemistry and U–Pb geochronological data were used to determine petrographic composition, geochemical nature, crystallization age and also to suggest a conceptual tectonomagmatic model for their emplacement. Small plutonic bodies are dominantly composed of monzogabbro that have intruded into the Cretaceous sedimentary rocks. Based on U–Pb zircon datings, these rocks have crystallized at 125–118 Ma in late Early Cretaceous (Barremian–Aptian), and are older than the supposed ages reported on geological maps. Varcheh rocks are not just typical calc‐alkaline rocks and some show alkaline affinity. Negative anomalies in Nb–Ta–Ti and enrichments in some large‐ion lithophile elements on spider diagrams are consistent with a subduction‐zone setting. Potential deep source for magma generation is partial melting of subcontinental lithospheric mantle wedge above a subducting slab of oceanic lithosphere. The spaces for the Varcheh mafic intrusions are accommodated by dominant dextral strike‐slip movement in a continental arc experiencing extension during late Early Cretaceous subduction. According to the zircon U–Pb geochronology results in this paper and previous U–Pb ages in the northern part of the SSZ, the mid‐Cretaceous magmatism reveals a significant NW‐ward younging trend and migration of the magmatic arc from the Barremian–Aptian in south‐east to the Albian–Cenomanian in the north‐west. [ABSTRACT FROM AUTHOR]

During the early Cenozoic, the collision and convergence between India and Eurasia resulted in the uplift of the Tibetan Plateau and continuous northward compression, forming the Circum‐Tibetan Plateau Basin and Orogen System (CTPBOS). The Tarim Basin, located between the Tibetan Plateau and the Tianshan Mountains, plays a crucial role for studying the convergence‐driving strain propagation mechanism intra‐Asian continent during the growth processes of the Tibetan Plateau. Owing to the lack of accurate geophysical information on the deep structure of the Tarim crust，the mechanism of Cenozoic deformation in the Tarim Basin has been under debate. In this paper, the teleseismic data acquired by the broadband seismic profile across the Tarim Basin from south to north and the S‐wave receiver function method were used to obtain the depth of the Moho and the discontinuities in the lithosphere beneath the Tarim Basin. The SRF result shows that the Moho geometry has an abrupt relief under the Bachu Uplift, and Moho offset under the fault zone between the Kalashayi Fault and the Tumuxiuke Fault. The regional dip of the Moho under the Bachu area can be explained by the root of the Bachu basement‐involved uplift cutting across the whole crust and locally penetrating into the mantle lithosphere. The Bachu Uplift, located in the central Tarim terrane, has a relatively weak lithosphere. In the process of forming the Tarim large igneous province during the early Permian, the crust beneath the Bachu area was weakened and thinned by the thermo‐mechanical erosion from upwelling mantle plume. As the collision and convergence of India and Eurasia since the early Cenozoic, the convergence‐driving strain was propagated into the Tarim Basin. The pre‐existing weak Bachu Uplift was reactivated. The Tarim Basin absorbs Cenozoic compressional deformation through the crustal shortening and Moho offset of the Bachu Uplift. [ABSTRACT FROM AUTHOR]

The present paper addresses petrography, geochemistry and Ar‐Ar geochronology of a significant number of mafic dykes from the Paleo‐ to Neoarchean Bundelkhand Craton in central India. The majority of the dykes are NW‐SE oriented (with a few NE‐SW and ENE‐WSW) with tholeiitic, sub‐alkaline and basalt to basaltic andesite composition. The trace element geochemistry of these dykes indicates an island arc setting during emplacement. The Ar‐Ar mineral dating (plagioclase) of three representative dykes reveals an emplacement age between 1.53 and 1.46 Ga. This finding and earlier reports (2.1–1.73 Ga) point to sustained mafic magmatism throughout the Bundelkhand Craton in a preferred structural orientation between 2.1 and 1.46 Ga. Mafic magmatism was episodic and can be linked to the perpetual subduction accretion processes between the central Indian Archean continents during the development of the Columbia supercontinent. The mafic dykes were emplaced at 45° to the maximum compression direction (E‐W), that is, along the line of no finite longitudinal strain. This time equivalent widespread NW‐SE and NE‐SW trending mafic dyke system is also relatable along the adjacent continents (Singhbhum, Bastar) and thus opened up a new paradigm for the dyke's emplacement across the Indian cratons. [ABSTRACT FROM AUTHOR]

Fluid diapirs are widespread in the northern South China Sea (SCS), are significant indicators of the existence and distribution of hydrocarbons and natural gas hydrates and are of great petroleum geological significance. Based on high‐precision 3D seismic and drilling data, this paper analyses the tectonic features and genetic mechanism of a fluid diapir zone in the northern SCS and a development model of fluid diapirs is proposed herein. Studies have revealed that the northern SCS large‐scale fluid diapir zone is located within a concealed structural transition zone, which is consistent with the spatial distribution location and direction of a concealed structural transition zone and that the formation of a fluid diapir zone is strongly influenced by the structural transition zone. Fluid diapirs are large continuously spreading bright reflection zones in shallow surface layers and are downwards converging high‐variance ribbons in middle and shallow layers, all of which are spreading in a NW–NNW orientation on the plane. The profile shows a conical or mushroom‐shaped shape that converges from shallow to deep, with a height of approximately 7 km and is characterized by a compound gas chimney fuzzy zone. The main body of the concealed structural transition zone is a slope structure and is flanked by large‐scale NW–NNW‐oriented fault systems. Minor en echelon spreading NW–NNW‐oriented faults and fractures are developed within the structural transition zone and are soft linkages that match well with the distribution direction and location of the fluid diapirs. On the profile, the overall display is a composite flower‐like structure dispersed from deep to shallow, which belongs to a large strike‐slip fault zone with a tectonic transformation effect. A comprehensive analysis suggests that the formation and development of the structural transition zone are mainly controlled by pre‐existing structures in the basement and that minor faults, fractures and slope zones within the structural transition zone serve as dominant pathways for the migration of deep overpressure fluids and gas hydrates. Consequently, the concealed structural transition zone provides favourable conditions for fluid diapirs to develop. Moreover, the stratigraphic overpressure systems mainly caused by gas generation provided the main driving force for the formation of fluid diapirs. Obviously, the development location, distribution direction, formation and evolution of the northern SCS fluid diapirs are jointly controlled by internal minor faults and fractures of the Eocene‐Miocene structural transition zone and the overpressure of the rifting period after the Pliocene. The main development period of the northern SCS large‐scale fluid diapirs was the second phase of the Dongsha Movement. During the exploration of gas hydrates and hydrocarbons in the Pearl River Mouth Basin, it is essential to consider the mutually restricting relationships between fluid diapir structures and gas hydrates and hydrocarbons. [ABSTRACT FROM AUTHOR]

To investigate the impact of solar energy on the carbon footprint, to find effective measures to reduce the carbon footprint and slow global warming as soon as possible, this paper takes 30 provinces in China as an example. First, the inter‐regional input–output model is used to calculate the carbon footprint of each province. Then, the panel quantile regression model is used to investigate the impact of solar energy generation on different quantiles of carbon footprint. The results show that from 2012 to 2020, China's carbon footprint is at a high level, which is not conducive to the achievement of the goal of peaking carbon dioxide emissions. The eastern region has the highest carbon footprint, followed by the western region, the central region has the lowest carbon footprint, and its carbon footprint proportion continues to decline. The increase of solar energy generation can significantly reduce the carbon footprint of high quantile location, but has no significant impact on the carbon footprint of the middle and low quantile locations. Except for the negative impact of afforestation area on carbon footprint, the others control variables are all positive. Therefore, to reduce the carbon footprint of China, it is necessary to upgrade solar technology, increase solar energy generation, reduce energy consumption per unit of GDP (Gross Domestic Product) and the share of coal consumption, strengthen forestry management and reduce reliance on private vehicles. [ABSTRACT FROM AUTHOR]

The Chinese government's use of fiscal policy, which includes fiscal income and spending, is crucial in its fight against environmental pollution and climate change. Innovation‐driven has arisen as a new alternative to reconcile economic success with environmental conservation in light of tighter resource restrictions and the suggestion of the Chinese High‐quality Development policy. The paper uses an econometric model to examine the connection between institutional resource consumption efficiency and carbon neutrality, using a data set consisting of Chinese inter‐provincial panel data from 2007 to 2020 as a research sample; fiscal decentralization is also discussed as a potential moderating factor. Collaborative innovation positively boosts ecological efficiency and produces geographical spillovers, and the findings suggest so long as the economic distance is considered. When it comes to increasing ecological efficiency, collaborative innovation plays a more important role than financial decentralization alone. Among these is the improvement of carbon neutrality, which is best achieved via the joint promotion of ecological efficiency and industrial organizations. By reducing the intensity of the positive effect of innovative cooperation on ecological efficiency, the moderating effect suggests that fiscal decentralization is a critical factor in this relationship. Promoting China's ecological efficiency necessitates a fair distribution of local budgetary spending. China should also actively encourage the degree of synergy between institutional resource consumption efficiency and associated institutions to improve eco‐efficiency. [ABSTRACT FROM AUTHOR]

Among several devastating natural hazards, flooding is a common and serious threat to society causing huge loss of lives, properties, and infrastructure throughout the world. The intensity and frequency of this extreme weather event are expected to increase due to significant changes in the present‐day climate and land use and land cover (LULC) pattern. India has a very systematic and organized structural program and policies but lacks proper implementations, and adverse effect of climate change and the extreme event goes on in society. This paper is an analysis of floods in India and hazards due to climate change and LULC change patterns. Three models, namely "Eco‐biogeography‐based optimization (EBO), Random forest (RF), and Support vector machine (SVM)" were used to obtain the final output to prepare a "Flood susceptibility map". The result was validated through the "Receiver operating characteristics (ROC)" with "Area under curve (AUC)" values. The future rainfall scenario has been estimated by considering the "General circulation models" through different "shared socioeconomic pathways (SSPs)". The values of AUC are 0.915 (EBO), 0.887 (RF), and 0.869 (SVM), respectively. After consideration of different SSPs, the result shows that there is an increasing tendency of flood hazards in the projected period. Among all the employed modelling approaches, the EBO model has notable potential in delineating the possible flood‐prone regions for effective flood planning and management. Decision‐makers can benefit from country‐specific information and regional planner to implement sustainable and long‐term measures to overcome this type of hazardous situation. [ABSTRACT FROM AUTHOR]

Energy is unquestionably necessary for economic progress, but it also results in carbon emissions, which are the leading cause of environmental deterioration and climate change. From this perspective, clean energy can contribute to both sustainable development and ecological sustainability, as it consists of non‐carbohydrate energy sources that do not or rarely emit greenhouse gases. In this context, this paper investigates economic policy uncertainty (EPU), economic expansion (EE) and clean energy consumption (EC) on carbon dioxide (CO2) emissions in Russia from 1995 to 2021. The autoregressive distributed lag (ARDL) model was used to illustrate the interdependence of factors. The error correction model (ECM) is also used to check the relationship among the study's desired factors. The long‐term investigation found that EPU harms the environment by increasing emission levels. The economic expansion increases CO2 emissions and reduces the environmental quality, supporting the ecological modernization argument. The consumption of clean energy negatively impacts CO2 emission; hence its higher amount reduces the carbon. Thus, the study found a causal relationship between EPU, EC, EE and CO2 emissions. Based on the study's findings, a policy framework is proposed to address the sustainable development goals and environmental quality. Adding the other variables like environmental regulations can be taken as future direction. [ABSTRACT FROM AUTHOR]

This paper combines new palaeomagnetic studies, palaeontological dating, and sedimentary analyses to propose a modified stratigraphic classification scheme in the northwestern Songliao Basin, which is of great significance for stratigraphic correlation, sedimentation analysis, basinal subsidence, and oil and gas exploration. New palaeontological and palaeomagnetic evidence redefined a group of semi‐consolidated lacustrine strata, buried beneath the Quaternary Yaluhe Formation on the Western Slope of the Songliao Basin, as Late Cretaceous, not the Middle Pleistocene. The chronostratigraphic framework re‐evaluates its stratigraphic age as late Coniacian to early Campanian (Late Cretaceous), between 83 and 85 Ma. Sedimentation research from 17 boreholes on the Western Slope of the Songliao Basin displays that the semi‐consolidated strata successively experienced lacustrine and delta facies deposits. Comparison of this new stratigraphy with the Late Cretaceous sequences on the adjacent Central Depression of the Songliao Basin reveals significant variations in lithology and palynological assemblages. Three new palynological assemblages are also reported from the Late Cretaceous sequences of the Songliao Basin. [ABSTRACT FROM AUTHOR]

Detrital single‐grain zircon U–Pb geochronology is a powerful tool for provenance studies if information on the source rocks is available. This paper proposes a new source‐rock classification tool that uses the degree of annealing of radiation damage in detrital zircon; the annealing is expressed by the relationship between the width (full‐width at half‐maximum; FWHM) of the v3[SiO4] Raman band at ~1008 cm−1 and the calculated α‐dose. The host rocks of the zircons are classified into three types according to their emplacement process and/or thermal history: volcanic and rapidly cooled plutonic and high‐grade metamorphic rocks (type 1); rocks with hydrothermal zircons (type 2); slowly cooled igneous and metamorphic rocks (type 3). We construct a naive Bayes prediction model by training it with a collection of zircons of known types. The unknown zircons are assigned a probability of derivation from a specific host‐rock type. This classification scheme is best used as an accessory tool in provenance studies that apply detrital zircon U–Pb geochronology. [ABSTRACT FROM AUTHOR]

There are several different models for the origin of syenites, but the role of magma mixing in the formation of syenites remains unclear. The Wulingshan alkaline complex in the northern North China Craton consists mainly of porphyritic syenite and syenite with abundant enclaves. These enclaves may provide new insights into the petrogenesis of syenites. We obtained zircon U–Pb age, mineral chemistry, whole‐rock major and trace elements, and Sr–Nd isotopic data for the enclaves and their host rocks to constrain the petrogenesis and identify the role of magma mixing during the formation of the different syenites in the Wulingshan alkaline complex. The results of zircon U–Pb dating indicate that the enclaves and host rocks crystallized contemporaneously at ca. 133 Ma. The enclaves contain abundant clinopyroxene, amphibole, and biotite, and their average Nb/Ta (18.46) and Th/Ce (0.04) ratios are similar to those of the mantle. The enclaves have relatively high Fe2O3T, MgO, and CaO contents, and their SiO2 contents are equivalent to those of intermediate rocks, indicating that they formed by mixing the mafic and felsic magmas to some extent. The different mineral assemblages, major and trace elements and isotopic compositions of the enclaves in the porphyritic syenite and syenite indicate that they are two batches of parental magma with different properties derived from the mantle. The porphyritic syenite and syenite have high SiO2 and low Fe2O3T, MgO, and CaO contents, as well as low V, Cr, Co, and Ni contents. These major and trace element characteristics of the host rocks require the involvement of crustal components. The Sr–Nd isotopic compositions of the enclaves and the host syenitoids plot on a mixing curve between enriched lithospheric mantle and lower crust, indicating that these rocks are the products of magma mixing and crust–mantle interaction. Considering the contact relationships, the geochemistry data, and the mixing model presented in the paper, we propose that the upwelling of the hot asthenosphere heated the overlying enriched lithospheric mantle and triggered low‐degree partial melting. The alkalic mafic magmas derived from enriched mantle sources were mixed with felsic magmas generated by partial melting of the lower (or upper) crust to form the different syenites. [ABSTRACT FROM AUTHOR]

This paper reports two types of basalt that have different ages (Carboniferous and Permian) but occur next to each other in the northern part of the Changning–Menglian accretionary wedge, southwestern China. We use the geochronology and geochemical data to evaluate the tectonic evolution of the Palaeo‐Tethys during this period. Zircon grains from the mafic‐ultramafic rocks associated with the Permian basalts in the Xiaomengtai area yield a U–Pb age of 281 Ma and εHf(t) values from +9.2 to +12.8. The Permian mafic‐ultramafic rocks and the associated basalts are all characterized by normal mid‐ocean ridge basalt (N‐MORB)‐like chondrite‐normalized rare earth elements patterns, moderately negative Nb‐Ta anomalies in the mantle‐normalized immobile incompatible trace element patterns, and positive εNd(t) values from +4.2 to +6.5, which are consistent with the geochemical characteristics of mafic‐ultramafic rocks in supra‐subduction zone (SSZ)‐type ophiolite. On the contrary, the Carboniferous basalts, which are associated with marine carbonates, are characterized by light REE enrichments, slightly positive Nb‐Ta anomalies, and εNd(t) values from +2.8 to +4.0. These features are similar to those of typical oceanic island basalts (OIBs) worldwide. Modelling results using REEs show that the parental magmas for the Carboniferous OIBs and the Permian basalts were likely derived from mantle peridotites at the depths of garnet and spinel stability, respectively, consistent with the formation depth of these two different types of basalt globally. The occurrence of these two different types of mafic‐ultramafic rocks with significantly different ages in the same area supports the view that they are the remnants of the accreted Palaeo‐Tethys oceanic crust. The Carboniferous OIBs are considered to be parts of an OIB‐carbonate seamount chain that originally formed in the southern part of the Palaeo‐Tethys. The Permian mafic‐ultramafic rocks are regarded as fragments of SSZ‐type ophiolites that were present in the northern part of the Palaeo‐Tethys. These different pieces of oceanic crust were accreted to the Simao–Indochina continental Block by subduction between the Late Permian and the Triassic. [ABSTRACT FROM AUTHOR]

More than 50 earthquakes occurred in the Luding region, including a 6.8‐magnitude earthquake on September 5, 2022, which induced huge amounts of geological disasters. As the main triggered factors for the geological disasters, the vegetation, precipitation and temperature show regular changes on the time axis. Thus, this paper based on the spatial–temporal evolution of the precipitation, temperature and normalized difference vegetation index (NDVI), focuses on the susceptibility of the Luding area using the weighted information content method (ICM) and analytic hierarchy process (AHP) for the post‐earthquake regional planning and reconstruction. In the Luding area, it was found that there were 18 debris flow gullies, and 470 geological disasters scattered in the debris flow gullies. The NDVI of the study area has been declining in recent years, with only about 12% of the NDVI increasing from 2015 to 2020. From 2011 to 2015, the annual cumulative precipitation has been dropping overall, while the July average temperature has increasing quadratic functions after decreasing trend. Furthermore, the studied area's geological hazards susceptibility was classified into five categories, with extremely low susceptibility accounting for 5.82%, low susceptibility accounting for 13.61%, moderate susceptibility accounting for 38.54%, high susceptibility accounting for 39.96% and extremely high susceptibility accounting for 2.08%. The geological disasters in moderate, high and extremely high susceptibility accounted for approximately 95.08%, and the covered area of geological disasters in moderate, high and extremely high susceptibility accounted for 88.06%. Through the receiver operating characteristic (ROC) curve of the model verification found the AUC = 0.743. The geological hazards susceptibility study results show that the approach is useful for the analysis and prevention of geological disasters. [ABSTRACT FROM AUTHOR]

The Dunhuang Basin, situated in western China along the Altyn Tagh Fault (ATF) zone, intersects the Tethys and Paleo‐Asian Ocean tectonic domains. Influenced by both the ATF system and the far‐field effects of the Qiangtang‐Lhasa‐Eurasia collision during the Mesozoic, the mechanism of the Jurassic sedimentary migration of the basin in response to tectonic movements is unclear so far. The paper uses a comprehensive approach, including field geological surveys, lithologic and lithofacies discern, stratigraphic relationships analysis and 2D seismic profile interpretation, to examine the distribution of Jurassic residual strata in the basin. The comprehensive results of our study suggest that the Dunhuang Basin exists as an isolated block with unique tectonic and sedimentary evolution characteristics. In the Early Jurassic, the Dunhuang Basin underwent initial rifting, leading to the formation of small segmented intermontane sags. This phase was marked by the coarse particle sedimentary system of alluvial fans and braided rivers, represented the near source rapid deposition in the initial formation period of the basin. Stratigraphic distribution was primarily influenced by pre‐Jurassic basement topography and was not significantly constrained by faulting during this period. The formation of these isolated discontinuous small intermontane sags indicates the segmented activities of the ATF in the Early Jurassic period. In the Middle Jurassic period, influenced by the ATF dextral strike‐slip faulting, sedimentation extended eastward and the depocenter migrated clockwise compared with the distribution of the Middle Jurassic strata within the Dunhuang Basin. This period witnessed the development of coal measure strata at the basin's margins and lacustrine fine‐grained clastic deposition in the centre. The segmented fracture of the ATF gradually initiated a unified dextral strike‐slip tectonic movement. In the Late Jurassic period, sedimentary strata were locally present in the Wanyao Sag but absent in other sags. The depocenter migrated counterclockwise compared with the distribution of Middle Jurassic strata within the Dunhuang Basin, due to regional uplift accompanied by the ATF sinistral strike‐slip faulting caused by the collision between the Lhasa Block and the Eurasia Plate. The depocenter migration of the Dunhuang Basin constrained within the ATF system from the Early to Middle and Late Jurassic can be attributed to the transition of the ATF strike‐slip faulting in context of the stress relaxation and compression between the collision of the Qiangtang and Lhasa blocks to the Eurasia Plate, respectively. [ABSTRACT FROM AUTHOR]

Liquefaction‐induced lateral spread is a kind of ground deformation caused by soil liquefaction, which is a danger to houses, roads and other infrastructures. In order to systematically investigate the influence law of different parameters on lateral displacement, this paper establishes a numerical model of the seismic responses of gently sloping grounds through the open‐source finite element software OpenSees and carries out a large number of calculations considering various working conditions. Based on the calculation results, eXtreme Gradient Boosting (XGBoost) and random forest (RF) regression are used to build the proxy models for lateral spread displacement prediction. The finite element model was verified by using the multiple VELACS No. 2 centrifuge experiments. Finally, the model was interpreted using SHapley Additive exPlanation (SHAP) method. The results of the model training showed that both models were able to achieve a good fit to the numerical calculation results, with the RF model having a smaller prediction error for the centrifuge experiments. The model interpretation results showed that the modified cumulative absolute velocity (CAV5) was the most important input variable in the model, and the importance of ground slope (S), relative density (Dr) and thickness of liquefiable soil layer (HL) was relatively high. In addition, the influence of each parameter on the lateral displacement is consistent with the actual situation, reflecting the rationality of the model prediction process. In addition, the results showed that there is a threshold for the modified cumulative absolute velocity (CAV5) and Arias intensity (Ia) that leads to a significant increase in lateral displacement. The thresholds of CAV5 and Ia are 1.3 g s and 1.0 m/s, respectively. These thresholds are in good agreement with the thresholds for triggering the overall initial liquefaction of the soil layer determined by related studies, which provides a reference for the evaluation of liquefaction‐induced lateral displacement. [ABSTRACT FROM AUTHOR]

The complex lithology, frequent interbedding and strong heterogeneity of the shale oil reservoir in Lucaogou Formation of the Middle Permian in Jimsar Sag lead to the complexity of litho‐electric parameters and the low accuracy of conventional reservoir saturation evaluation methods. Therefore, in this paper, automatic lithologic identification was firstly performed with the optimization inversion method of mineral components and K‐means clustering algorithm, and then, litho‐electric experiments were carried out to determine the litho‐electric parameters of different lithologies. Furthermore, the shale oil reservoir saturation calculation models of different lithologies were optimized and determined. Then, a composite water saturation model (Composite‐SW) based on complex lithology identification was constructed. Finally, the model was verified and analysed with the experimental results of water saturation. The coefficient of correlation between the calculation results of the Composite‐SW model and the core experiment results reached.88, indicating that the model was much better than conventional models. The model can be widely applied in logging evaluation of the continental mixed shale oil reservoir in the study area. The study provides a new idea for oil saturation evaluation of continental shale oil reservoirs and is significant for evaluating other types of shale oil reservoirs. [ABSTRACT FROM AUTHOR]

The North Qinling Orogenic Belt (NQB) records the pivotal geological information for understanding the Palaeozoic evolution of the Qinling Orogenic Belt (QOB). Previous studies mainly focused on the subduction–collision process along the Shangdan suture zone before the Early Devonian. However, as the significant interim period between the Early Palaeozoic and Mesozoic orogeny, the Late Palaeozoic tectonic evolution of the NQB remains poorly understood. Fortunately, the Carboniferous magmatic rocks discovered this time provide substantial geological evidence for revealing the Late Palaeozoic tectonic history of the Qinling Orogenic Belt. This paper will provide a detailed analysis of zircon U–Pb ages, geochemical characteristics and Sr‐Nd‐Hf isotopic compositions of Carboniferous rocks. The Carboniferous magmatic rocks are categorized as highly differentiated S‐type granite and monzodiorite, formed at 350 ± 2.4 Ma and 353 ± 5.2 Ma, respectively. The granite shows weak peraluminous (A/CNK = 1.02–1.11) and shoshonite nature. Based on the isotopic composition and trace element characteristics, we propose that the Qinling Group paragneiss is the primary source of the Carboniferous granite. Monzodiorite is characterized by enriched LREEs and LILEs (Ba, K and Pb), depleted HFSEs (Th, Nb, Ta and Ti) and enriched Sr‐Nd isotopic composition. Monzodiorite magma source region consists of continental crustal material and lithospheric metasomatized mantle. Carboniferous magmatic rocks are the product of an extensional tectonic setting, which indicates the NQB tectonic regimes transition from compression to extension during the Carboniferous. [ABSTRACT FROM AUTHOR]

Understanding of fault propagation in pull‐apart basins is important due to its control on the depocenter migration, which is a common characteristic of pull‐apart basins; nevertheless, the evolution law of faults in the pull‐apart basin is not very clear. Most studies based on physical simulations have rarely paid attention to the relationship between fault propagation and migration of the depocenter. In this study, we simulate the fault propagation in the underlapping, neutral and overlapping releasing bend via the discrete element simulation method and discuss the corresponding migration of the depocenter. In this paper, more parameters (maximum shear force, distribution of tensile contact force, measuring stress) were used together to find out the evolution law of faults in line with natural basins. The results reveal the process of fault propagation, which has not been proposed in the previous simulating and case studies: the fault propagates from the ends of the master faults to the centre of the releasing bend and then proceeds externally. Consequently, the depocenter of the basin, which has undergone migration, experiences a transition from the dual depocenter state at the ends of the master faults to being a single depocenter at the centre of releasing bend and finally further expands in an outward direction. The characteristics of fault development and depocenter migration for the Khanguet Sidi Neji‐Gafsa (KSG) Basin, the Vienna basin and the Gulf of California are in accord with the results observed in the simulation. This study provides a new understanding of the fault propagation in pull‐apart basins and can assist in the interpretation of the evolutionary stages that pull‐apart basins undergo. [ABSTRACT FROM AUTHOR]

The spatiotemporal coupling relationship between deep hydrocarbon fluid and sandstone uranium mineralization within the shallow buried red‐variegated clastic rocks in the Qianjiadian area of the Songliao Basin remains a topic of controversy. This paper aims to provide a comprehensive understanding of the source, nature and exudative age of deep exotic hydrocarbon, as well as the interaction mechanism and alteration process between hydrocarbon fluid and clastic rock. To achieve this, various methods were employed, including acidolysis hydrocarbon test (AHT), clay x‐ray diffraction (XRF), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), carbon isotope analysis (CIA) and LA‐ICP‐MS U–Pb isotopic dating. The results indicate that some tight sandstones from the Qingshankou Formation in Dalin uranium deposit exhibit high acidolysis hydrocarbon content (AHC), reaching n × 104 μL/kg, and predominantly consisting of low mature oil‐type gas. Local microscopic observations reveal pore fluorescence and hydrocarbon‐bearing inclusions with nattier blue tone. Furthermore, the kaolinites present in the ore area's sand‐bodies show a significantly higher content anomaly, commonly exceeding >50%, compared to the same layer in peripheral regions. Extensive dissolutions of lithic grains and feldspars are observed, along with the widespread occurrence of ferro‐dolomites and colloidal pyrites. Additionally, exotic asphaltenes are sporadically developed in localized areas. These findings provide evidence that the sand‐bodies experienced a significant exfiltration event of external gaseous fluids. The light carbon isotopes (δ13CV‐PDB ranging from −33.26‰ to −30.06‰) of group components and n‐Alkane suggest that the hydrocarbon originates from the source rock of the Lower Cretaceous Jiufotang Formation. A detailed two‐stage alteration sequence caused by acidic and reducing hydrocarbon is clarified, encompassing acidic corrosion, kaolinization, pyritization, silification and asphaltization during the exudation stage, followed by ferro‐dolomitization in the later cessation stage. Notably, vermicular secondary kaolinites, formed through the interaction between acidic hydrocarbon fluid and low‐temperature meteoric groundwater, serve as significant markers for the exfiltration of deep hydrocarbon fluid. In‐situ U–Pb dating of hydrocarbon‐bearing ferro‐dolomite yielded absolute exfiltration ages of 63.54 ± 4.13 and 65.93 ± 3.35 Ma. By integrating the tectonic–sedimentary–fluid evolution history and uranium mineralization characteristics in the study area, a three‐stage superimposed metallogenic model is proposed for the Upper Cretaceous red‐variegated layers: (1) the sedimentary and diagenetic stage of the target layer during the Late Cretaceous, (2) the predominant hydrocarbon exudation stage at the end of the Late Cretaceous, and (3) the main uranium mineralization stage since the Paleogene. This study enhances our understanding of coupled‐genetic sandstone‐type uranium deposit in a sedimentary basin and provides valuable guidance for prospecting similar red‐variegated beds in the Songliao Basin and other sedimentary basins worldwide. [ABSTRACT FROM AUTHOR]

The establishment, development and abandonment and/or destruction of ancient civilizations were catalytically controlled by geomorphic features such as lakes and rivers and the climate. This paper examined the possible influence of tectonism and climate on six habitations of the ancient Vaigai River Basin civilization in South India, using multiple proxies such as grain size, geochronology and geochemistry of the sedimentary archives. The tectonic setting of the basin changed between the active margin and passive margin; the discriminant diagrams suggested varying provenance and changing climatic conditions over the mid‐ and‐late Holocene. Tectonic activism and quiescence, base‐level change in the channel morphology led to the burial/marooning of the first habitation surface. Overall, arid conditions were punctuated with catastrophic flooding and peak discharge (flood) destroyed the second, third and fourth habitation sites. These flooding events were characterized by moderate weathering (CIA) and high values of Al, Fe and Rb/Sr and low Ca/Mg in the sediment records. The abandonment/destruction of the fifth habitation also occurred during an arid interval (droughts), possibly caused by weak monsoon. Along with the interactions between tectono‐climatic and fluvial geomorphic factors, the new results provided avenues to (a) check and recognize the archives for 8.2 and 4.2 ka‐like events in this part of the world, and (b) the utility of integrated analyses to constrain on the civilizational histories of the mankind. [ABSTRACT FROM AUTHOR]

Many years after construction, a number of existing old tunnels and underground structures are deteriorating with time as evidenced by cracks, large deformations, water leakage and so forth, which usually require regular site inspections to record their structural deterioration by taking high‐pixel, high‐overlap images along miles of a tunnel network. For complex underground structures (e.g., long tunnels and large caves), unmanned aerial vehicles (UAVs) may be adaptive in acquiring images at multiple heights and angles with low operational costs. So far, UAV underground structural health monitoring has become mature for open‐air surveying with rapid developments in robotic software and hardware. However, the UAV image acquisition for underground working conditions still faces a number of key challenges. This paper aims to provide an overview of UAV navigation techniques in confined dark spaces for geotechnical engineers, geologists, drone developers and other interdisciplinary researchers & professionals in the structural health monitoring field. It specifies the challenges for UAV application in underground space, mainly including lack of Global Navigation Satellite System (GNSS) signals, poor lighting conditions, weak features and obstacle avoidance and then followed by strategic solutions. For example, in light of poor GNSS signals, the fusion of multi‐sensors (e.g., laser imaging, detection and ranging (LiDAR) and multi‐cameras) can enhance localization accuracy in low‐luminance underground conditions. To address obstacle avoidance, computer vision (CV)‐based navigation algorithms (e.g., deep reinforced learning [DRL]) enable effective navigation in complex 3D spaces, but their adaptability is limited by arithmetic power and pre‐training needs. The review of relevant previous studies concludes that further development for UAVs in underground space inspection may focus on operation in large‐scale geometric inspection environments, obstacle avoidance, features and semantic recognition. [ABSTRACT FROM AUTHOR]

Pore structure impacts the capability of seepage pattern of subsurface fluid mineral and mineral exploitation efficiency. Because of the strong heterogeneity in carbonate reservoirs, the pore structure is nonlinearly varying and complex in reservoirs. It is necessary to establish a method for pore structure type (PST) prediction. Machine learning provides an efficient prediction method by finding the relationship between core test data and well‐logging data. In this paper, a reservoir identification method based on Gradient Boost Decision Trees (GBDT) is proposed for the pore structure characteristics of carbonate reservoirs integrating core test and logging data. Core testing data are utilized to form the training set for PST prediction. Then, we adopt the mutual information method to optimize the logging data as the input of the machine learning model. GBDT hyperparameters are optimized using the learning curve to make it have optimal performance. Finally, we compare the predicted result of GBDT with K‐Nearest Neighbor and support vector machines, demonstrating the superior performance of GBDT. The results indicate that the four PS are different in some properties, such as permeability, pore radius and shape of pore and throat. 20%, 10 and 0.15 are recommended as the optimal parameter values for Maximum feature, iteration number and Sub‐sample number to improve GBDT accuracy in carbonate reservoir PST prediction. Evaluation indicators of machine learning, including the Kappa coefficient, Heming distance, Jaccard similarity coefficient and Confusion matrices, indicate that GBDT has better performance. This research proves the high accuracy and applicability of machine learning technology in the carbonate reservoir and also provides a meaningful reference for the identification of the carbonate reservoirs in the central area of Iraq. [ABSTRACT FROM AUTHOR]

Edge waves generated by subaerial landslide‐tsunamis (SLTs) often have potentially huge amplitudes that can endanger human lives, offshore structures, coastal cities and port facilities around reservoirs. Maximum edge wave run‐up (RuM) is the most important parameter for SLT hazard mitigation in an engineering context. This study aimed to investigate the effects of the hill slope angle α on RuM, the first edge wave run‐up Ru1 and the first edge wave decay in the near field Ru1(r/h) through 84 laboratory experiments, which were conducted in a three‐dimensional river channel with α values varying from 15° to 40°. For smaller α values, we found that RuM increased with the increase in α while for large α values exceeding 30°, RuM decreased with the increase in α. An empirical equation considering the effect of α was proposed for the prediction of RuM in the near field, which was well verified by a real case. Additionally, the first edge wave run‐up decay along the shore is also discussed in this paper. This work could have some favourable implications for the preliminary hazard assessment of SLTs. [ABSTRACT FROM AUTHOR]

Detecting slope deformation is an important issue in engineering. Timely deformation detection can effectively avoid catastrophic slope failure and ensure the safety of a project and engineering personnel. In this study, deformation detection for a quarry slope is implemented using the integration of subpixel offset tracking (sPOT) and unsupervised change detection algorithms based on unmanned aerial vehicle (UAV) image datasets. The sPOT algorithm is used to give the surface displacement field of the slope with subpixel accuracy, and the unsupervised change detection algorithm yields the ground object reconstruction area of the slope to verify and explain the sPOT result. The integrated analysis method in this paper is highly applicable and only requires a minimum of two UAV datasets as raw data. Combining the advantages of the sPOT and unsupervised change detection algorithms, the proposed method has the ability to detect and analyse slow and rapid slope deformation with good accuracy. [ABSTRACT FROM AUTHOR]

Landslides with step‐like deformation features are widely distributed in the Three Gorges Reservoir area (TGR) of China, posing a severe hazard to the inhabitants of this region. This paper proposes a multi‐input and multi‐output intelligent integrated displacement prediction model for landslides with step‐like displacement patterns. In this new model, three interconnected and information‐transmitted functional sub‐models are integrated. Unsupervised learning is used to identify different landslide deformation states automatically, and the imbalance classification and explainable artificial intelligence techniques are introduced for qualitative prediction and information filtering. Probability theory and deep machine learning are adopted to provide deterministically predicted values and quantify their uncertainty. The case study of the Baijiabao landslide in the TGR region proves that the proposed model performs satisfactorily in both point and interval predictions. The intelligent integrated model can also provide the forecast of landslide deformation states, visual input information filtering and back analysis of influencing factors, which are valuable to landslide early warning and risk management. [ABSTRACT FROM AUTHOR]

Landslide susceptibility mapping (LSM) has been widely used as an important reference for development and construction planning to mitigate the potential social‐eco impact caused by landslides. Originally, most of those maps were generated by the judgements of experts, which is time‐consuming and laborious, and whose accuracy is difficult to be quantified because of the subjective effects. With the development of machine learning algorithms and the methods of data collection, big data and artificial intelligence have now been popularized in this field, significantly improving mapping accuracy and efficiency. Various machine learning‐based methods, mainly including conventional machine learning, deep learning, and transfer learning have been applied and compared in LSM in different areas by previous researchers. Nevertheless, none of them can be effective in all cases. Although deep learning‐based methods were proven more accurate than conventional machine learning‐based methods in most data‐rich situations, the latter is sometimes more popularly used in LSM, as there is not that much data in this field to train a deep learning network perfectly. In a more rigorous situation when there is very limited data, transfer learning‐based approaches are applied by several researchers, which have contributed to improve the workability and the accuracy of LSM in data‐limited areas. Such technical explosion has promoted the application of landslide susceptibility maps, thus contributing to mitigating the social‐eco impact associated with landslides. This paper comprehensively reviews the whole process of generating landslide susceptibility maps based on machine learning methods, introduces and compares the commonly used machine learning methods, and discusses the topics for future research. [ABSTRACT FROM AUTHOR]

Low and ultra‐low permeability reservoirs are widely developed in the Upper Triassic Yanchang Formation in the Ordos Basin, and its intricate pore throat structure has a significant impact on the physical properties and heterogeneity of reservoirs. This paper conducted a series of experiments to investigate the petrology, pore structure, fractal characteristics of ultra‐low permeability sandstone reservoirs, and influencing factors of the physical properties. The results show the sixth member of the Yanchang Formation (Chang 6) reservoir in the Xiaojiahe area is dominated by feldspathic sandstone. The main pores are intergranular pores, followed by dissolution pores. The Chang 6 sandstone has been categorized into four types (type I–IV) based on the traits of mercury intrusion curves. The high content of quartz and feldspar in the detrital components is conducive to improving the physical properties of the reservoir. The pore‐throat structure parameters, such as displacement pressure, median pressure, and pore throat radius can characterize the change in physical properties and reservoir quality. According to the capillary pressure fractal model of rapex (Pittman's plot apex radius), demonstrating the ultra‐low permeability, sandstone has a binary structure. The fractal dimensions D2 and Dp are more appropriate for characterizing the heterogeneity of the pore structure. The effects of different pore‐throat size scales on the physical properties of the reservoir have a discrepancy. Relatively large pore throats (r > rapex), non‐nanoscale pore throats (Porr>0.1), and effective movable pore throats (Porem) have significantly positive control effects on permeability and reservoir quality. In contrast, the development of nanoscale pore throats (Porr<0.1) and micropore throats of failure to enter mercury (Porfem) are unfavourable to reservoir performance. In conclusion, combining detrital components, pore‐throat structure, fractal characteristics, and other factors controlled the reservoir quality of ultra‐low permeability sandstone. [ABSTRACT FROM AUTHOR]

The Permian–Triassic boundary (PTB) volcanic tuffs are widely distributed in the East Palaeo‐Tethys region, but their age and origin have been controversial. The Permian–Triassic deep‐water sediments in the northeastern margin of South China are favourable research objects, and we report new results from the PTB deep basin sediments in the Susong area, Anhui Province, in this paper. Two volcanic tuffs are found in the Zuoshan PTB in the Zuoshan section, and Laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) U–Pb zircon dating indicates that the upper and lower tuffs are 251.3 ± 1.7 Ma and 252.3 ± 2.1 Ma, respectively. The PTB age is 251.6 Ma according to a numerical interpolation method of the average deposition rate of the PTB. Fusulinids and non‐fusulinid foraminifers in the limestone overlying the lower tuff define the rock as end‐Permian. Zircon trace elements show that both tuffs are sourced from felsic volcanism in continental arc background, and their source magmas were derived from the continental crust. Zircons of PTB age from the upper tuff on the bottom of the Triassic have negative εHf(t) value from −8.02 to −3.75, and the Palaeo‐Mesoproterozoic two‐stage model ages of 1502–1780 Ma, showing that their source rocks were only derived from the remelting of the Palaeo‐Mesoproterozoic continental crust. The zircons from the lower tuff on the top of the Permian show two types, including negative εHf(t) values from −6.48 to −1.25 and Palaeo‐Mesoproterozoic two‐stage model ages of 1350–1679 Ma, and positive εHf(t) values from +3.98 to +10.15, and Neoproterozoic two‐stage model ages of 629–1023 Ma, indicating that their sources were derived from the reworking of the Palaeo‐Mesoproterozoic continental crust and early Neoproterozoic depleted mantle joined in juvenile crust growth in the northern margin of the South China Block at the beginning of the collision between the South China and North China blocks. The initial collision started no later than 252.3 Ma and developed significantly from east to west. [ABSTRACT FROM AUTHOR]

The Zhaojinggou Nb–Ta deposit is one of large rare metal deposits newly discovered in the northern margin of the North China Craton in recent years. This paper reports petrography, petrochemistry, columbite‐group minerals U–Pb chronology study of the amazonite granitic pegmatite (AGP) exposed in this deposit, and composition of columbite‐group minerals and biotite are obtained by electron probe microanalyzer and LA‐ICP‐MS. Eighteen analyses of columbite‐group minerals yielded weighted mean 206Pb/238U age of 116.9 ± 1.4 Ma. The crystallization temperature of biotite is 630–650°C, and the oxygen fugacity is 10−17–10−18 bars. The biotite has low MgO contents and high Rb, Rb/Sr, and FeOT/(FeOT + MgO) ratios. The AGP has extremely low MgO, Cr, Co and Ni contents, with Nb/Ta ratios range from 1.63 to 9.05 and Rb/Sr ratios range from 303.30 to 648.90, and obvious 'M' type tetrad effect of rare earth element indicating that the formation of the AGP is related to crust‐derived magma. The contents of Nb2O5 and FeO decrease, while the Ta2O5 and WO3 contents, Mn# and Ta# values increase gradually from the core to the rim of columbite‐group minerals. Some columbite‐group minerals have unobvious oscillatory zoning, and some have a clear bright zoing with high Ta contents on the rim, indicating that the genesis of Zhaojinggou Nb–Ta deposit is mainly magmatic crystallization differentiation, accompanied by hydrothermal autometasomatism in the late stage. [ABSTRACT FROM AUTHOR]

Research on the Bengal Basin, the most important sedimentary basin in the world that supports ~200 million people, is primarily focused on its geologic evolution and anthropogenic effects, yet the basin is poorly studied in terms of geomorphic response to tectonic activity. The eastern part of the Bengal Basin is characterized by the Chittagong Tripura Fold Belt (CTFB) and the Indo‐Burman Range (IBR), which have structurally deformed into a series of mostly compressional fold and thrust belts including strike–slip faults because of the ongoing subduction‐related convergence between the Eurasian Plate and the Indian Plate. A network of river channels incising through thick sedimentary rocks and crossing and/or flowing parallel to this fold and thrust Belt. The active tectonic deformation caused by the structures and ongoing compression‐related activity remains enigmatic due to the sparse dataset, thick vegetation cover, outcrop paucity, and the Basin's complex geology. In this paper, we investigate river response to ongoing tectonics in the CTFB and western IBR by analysing channel geomorphic metrics (ksn, χ, and knickpoints) coupled with river profile forms derived from 30 m resolution NASADEM. Our results reveal (1) several convex and double‐concave reaches of major rivers and their tributaries that primarily indicate the transient state of the rivers; (2) a total of 219 upstream propagating knickpoints including distinct knickzones in profile reaches, suggesting river profile adjustment; (3) two different ksn zones in the CTFB and IBR with high ksn zone to the east and low ksn zone to the west, where ksn values range from 0 to 4905. These zones are thought to be associated with the differential uplift rate of the two east‐dipping thrust fault systems, the Kaladan Fault and Chittagong Cox's Bazar Fault (CCF); and (4) the χ‐ map (values ranging from 0.47 to 19,631.75) shows an occasional transient state of drainage divides where divides are migrating to the east, west, and north‐east, and χ versus elevation plots exhibiting disequilibrium state of the rivers suggesting that these drainage basins are likely adjusting with tectonic activities. Thus, our empirical observation suggests that the major rivers and their tributaries are in a transient state related to the region's overall ongoing tectonics. [ABSTRACT FROM AUTHOR]

As one of the pioneer palaeontologists, Professor Zhuoting Liao has contributed his lifetime to promoting palaeontological and stratigraphical research in China for 60 years, and he passed away in the field excursion in South China on June 20, 2020. In his palaeontological career, Liao has worked on Late Palaeozoic to Mesozoic palaeontology and stratigraphy of almost all regions across China, and his interests have also extended to the Permian–Triassic (P‐Tr) boundary and mass extinction. He has worked on palaeontology, palaeobiogeography, biostratigraphy, tectonostratigraphy, and their implications in mineral and oil‐gas industries. Liao has established 22 new genera and 172 new species of brachiopods, and, together with his colleagues, proposed 11 new genera and 25 new species of echinoderms. He dedicated his lifetime to work on Late Palaeozoic palaeontology and stratigraphy of the previously remote and tectonically complex Xinjiang and adjacent regions, north‐west China, and established integrated stratigraphical frameworks for the Carboniferous to Permian strata, providing fundamental basis for mineral and hydrocarbon exploration in the poorly understood Central Asian terranes. In addition, he has mentored many young palaeontologists and stratigraphers in various ways. This volume assembles 30 papers addressing the Late Palaeozoic to Mesozoic palaeontology and stratigraphy of China and adjacent regions, which pays tribute to the achievement of Professor Zhuoting Liao. [ABSTRACT FROM AUTHOR]

The Devonian Heyuanzhai Formation was re‐investigated in its type area in Shidian, Baoshan Block, western Yunnan, China. The sequences crop out at the Douyashan section adjacent to the Heyuanzhai village where they were measured. They are represented by thick fossiliferous successions of carbonate deposits interbedded with calcareous shale and mudstone. A great number of fossils were collected from the formation, with detailed documentation of brachiopods, crinoids, and ostracods in this paper. In the lower and middle parts of the Heyuanzhai Formation, the brachiopod Gypidula‐Schizophoria‐Spinatrypa assemblage is recognized and generally correlated to the Eifelian–Givetian. Whereas, in the upper part, the brachiopod Pugnax‐Hypothyridina‐Tenticospirifer assemblage is recognized for the first time, indicating an Early‐Middle Frasnian by occurrences of new species of rhynchonellid and cyrtospiriferid brachiopods, as well as the middle Late Devonian crinoids (Megaradialocrinus, Halocrinites, and Melocrinites) and ostracods (Palaeocopida, Platycopida, Metacopina, Podocopida). The sedimentary facies association and fossil assemblages herein indicate that the Heyuanzhai faunas from the Douyashan section inhabited a turbulent mid‐ramp with depth between the fair‐weather wave‐base and storm wave‐base, and were possibly accumulated in an environment that was derived from immediately adjacent habitats after short‐distance transportation. [ABSTRACT FROM AUTHOR]

The Jiamusi Block is a crucial geological unit joining multiple tectonic regimes, including the Late Palaeozoic Palaeo‐Asian Ocean and the superposition of the Early Mesozoic Palaeo‐Pacific tectonic domain. However, the duration of the Palaeo‐Pacific Plate subduction beneath the Jiamusi Block has long been controversial. In this paper, we focus on clastic rocks from the Nanshuangyashan and Yunshan formations on the east margin of the Jiamusi Block and use the modal analysis of sandstones and detrital zircon U–Pb dating to trace the subduction history of the Palaeo‐Pacific Plate. Our analysis results suggest that the two groups of samples are characterized by a high content of monocrystalline quartz and a low content of lithic and feldspar, indicating that the sedimentary provenances were stable continental blocks and magmatic arcs. The detrital zircon ages of the Nanshuangyashan Formation have a major peak at ca. 245 Ma and two secondary peaks at ca. 470 and 228 Ma, respectively. The Yunshan Formation has a major peak at ca. 494 Ma and a secondary peak at ca. 265 Ma. The provenances of the Nanshuangyashan Formation were attributed to the Jiamusi Block, Khanka Block, and a Late Triassic magmatic arc. Similarly, the provenances of the Yunshan Formation were attributed to the Jiamusi and Khanka blocks. Detrital zircon analysis results show that the eastern margin of the Jiamusi Block was in the same back‐arc basin settings in the Late Triassic and the Late Jurassic. Thus, we propose that the eastern margin of the Jiamusi Block had been affected by the Palaeo‐Pacific Plate subduction in the Late Triassic and had continued to the Late Jurassic. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of water level oscillation and sediment supply volume on shallow‐water delta development by means of a flume experiment. The experiment simulated the natural water level by dividing a cycle of sediment period into four parts: the draught period, the flood period (FP), the interflood period in a falling limb (IPF) and the interflood period in a rising limb (IPR). During the FP, flooding broke former channels and a large amount of sediments were evenly unloaded at the surface of lobes. Erosion often appeared at the beginning of the IPF and was dominant at low stand. Most sediments were concentrated in incised valleys and unloaded at the channel mouth to form a new lobe during the falling limb. Erosional channels and lobes were broken at the IPR. Sediments homogeneously covered the surface of lobes and few new lobes appeared during the period. Different sediment supplies influenced the characteristics of incised valley and channel style. Low sediment supply to the delta was strongly influenced by water level change, while high sediment supply was mainly affected by fluvial processes. Based on the flow sand content of water, channels can be classified into four types: (a) narrow and deep multiple channels, (b) narrow and shallow branch channels, (c) broad and shallow main channels, and (d) broad and deep stable channels. Their width‐to‐depth ratios are 1.1–3.5, 5.1–12.9, 7.3–20.2, 2.6–4.6, respectively. Most mouth bars were initially formed but then broken by water level oscillation and channel bifurcation. The preserved mouth bars were well preserved at the far end of lobes, where they entered the low‐energy environment. [ABSTRACT FROM AUTHOR]

Olivine crystals in alkaline basalts preserve important information about the Oxygen fugacity and thermal condition of the mantle‐derived magma. This paper presents new olivine mineral chemistry and whole‐rock geochemistry for Early‐Cretaceous alkali basalts in the Ganjia area, northeastern margin of the Tibetan Plateau. The olivine phenocrysts of Ganjia basalts have low Ni (74–2261 ppm) and high Ca contents (1217–4443 ppm), similar to the olivines in MORB, suggesting that they were crystallized from peridotite‐derived basaltic magma. Al‐in‐olivine/spinel thermometer results indicate crystallization temperatures of olivine around 1202 ± 46°C, corresponding to a mantle potential temperature of 1279 ± 47°C, with low oxygen fugacity of FMQ −1 to FMQ 0, suggesting a reduced mantle source. Whole‐rock geochemical compositions of the Ganjia basalts were characterized by low SiO2 contents (45.39%–48.70 wt%), high alkali contents (3.88–5.11 wt%), positive Nb and Ta anomalies, and enrichment in LREEs, HFSEs and LILEs, similar to those of OIB rocks, with high ratios of (Dy/Yb)N (1.38–1.54) and (La/Yb)N (5.37–7.42) ratios, indicating garnet residue. The above results suggest that the Early Cretaceous intraplate alkaline basalts in West Qinling were formed by a low degree of partial melting of peridotite and that no high‐temperature mantle plume existed. The Qinling Orogenic Belt may have been affected by the subduction of the Palaeo‐Pacific. We propose that the Ganjia basalts originated from the interaction between the upwelling asthenosphere and a lithospheric source. [ABSTRACT FROM AUTHOR]

The paper presents data on the U–Pb chronology of detrital zircon grains and radiogenic isotopic composition (87Sr/86Sr, ɛNd) from the Proterozoic clastic successions of the Garhwal‐Kumaon Lesser Himalaya representing the extended northern Indian cratonic margin, NW India. The Proterozoic Lesser Himalayan Basin in Garhwal‐Kumaon Himalaya is divided into two sectors, namely, Inner Lesser Himalaya (ILH) and Outer Lesser Himalaya (OLH) by a tectonic boundary, namely the Tons Thrust (TT). Age distribution from inner and outer sectors of the Lesser Himalaya shows that the U–Pb chronology of most of these zircons provides Palaeoproterozoic (between 1.6 and 1.8 Ga) to Neoproterozoic (800 Ma) ages. The age data suggest sedimentation of the Rautgara Formation (Damtha Group) of ILH continued till the Neoproterozoic (~850 Ma), which was earlier regarded as ≤1.6 Ga. Tracking the detrital U–Pb zircon ages in the near adjacent cratonic parts point towards Aravalli Orogen as the major source region. Whole‐rock ƐNd(0) values for ILH rocks range from −37.6 to −14.6 and for OLH it ranges from −19.6 to −6.7. More negative ƐNd values along with dominance of Neoarchean‐Palaeoproterozoic ages in ILH indicates supply from more evolved protolith or recycled sources and less negative ƐNd values with major Neoproterozic zircon ages from OLH supports for less evolved source rock. The change from more negative ƐNd to less negative ƐNd values progressively upward the stratigraphy can be due to a shift in source with time. Both U–Pb zircon and ƐNd supports for a continuous sedimentation model, rule out the presence of ~500 Ma unconformity within the LH and argues for separate evolution of the Lesser Himalayan Basin on the trailing edge of the extended north Indian craton in "Columbia" configuration. [ABSTRACT FROM AUTHOR]

The tight sandstone reservoirs have become the focus of today's oil and gas exploration. To clarify the microscopic characteristics of the tight sandstone reservoirs of the Chang 63 deep water gravity flow origin in the Huaqing area, the Chang 63 gravity flow origin reservoirs in the study area are divided into three categories. They are the formation reservoir of sandy clastic flow (FROSF), formation reservoir of muddy debris flow deposits and turbidites (FROMT) and formation reservoir of slides and slumps (FROSS). In this study, core and logging data, thin sections, field emission scanning electron microscopy (FE‐SEM), and mercury intrusion capillary pressure (MICP) were combined to investigate the rock composition and pore‐throat characteristics of tight sandstone reservoirs with different types of gravity flow origins. The reservoir micro‐heterogeneity is also investigated in this paper. The results show that the reservoirs with different gravity flow origins are similar in lithology and are mainly composed of feldspar lithic sandstone and lithic feldspar sandstone. The pore types are mainly intergranular pores and feldspar‐dissolved pores. There are significant differences in the porosity, permeability, microscopic pore‐throat characteristics and microscopic heterogeneity of the reservoirs. From FROSF to FROMT and FROSS, the porosity, permeability, mercury inlet saturation, discharge pressure, median pressure and mercury removal efficiency gradually decrease. The tightness of the reservoir gradually increases. The storage capacity is gradually reduced. The disparity between the throat radius and pore radius gradually increases. The pore‐throat structure becomes more complex, and the microscopic heterogeneity of the reservoir gradually increases. [ABSTRACT FROM AUTHOR]

This paper presents a survey of geological attributes on the lateritic‐bauxitic deposits to examine their provenance, palaeogeography, and palaeoclimate condition in the Permian–Triassic boundary of Alborz Mountain, north Iran. The mineralogical analysis revealed that haematite, quartz, goethite, kaolinite, diaspore, boehmite, and anatase are the major rock‐forming minerals in these deposits. The major oxide composition of samples detected that enrichment of Al2O3 (up to 31.5%) and Fe2O3 (up to 37.9%) led to the formation of laterite, kaolinitic laterite, and bauxitic kaolinite. The distribution of trace and rare elements provides information about the enrichment of deposits concerning immobile elements. Employing geochemical proxies such as Al2O3/TiO2, bivariate diagrams of Eu/Eu* versus Sm/Nd and TiO2/Al2O3, enrichment of samples relative to heavy rare earth elements, and positive Eu anomaly revealed that the deposits originated from intermediate to mafic rocks. Several factors are inferred to be responsible for the transformation of parent rock(s) into lateritic‐bauxitic deposits: The high values of CIA, CIW, and PIA (mostly above 80) and increase of kaolinite point to deep to moderate parent rock(s) weathering, which is consistent with warming and humidity around the Permian–Triassic boundary. In continuation, transportation and trapping of weathered materials above the karstified carbonate bedrock of the Ruteh Formation and environmental interactions induced the formation of new minerals in a transitional environment near the vadose zone. The deposits have a generic correspondence with Palaeotethys Oceanic crustal subduction due to tectonic uplift, exhumation of bedrock, and regional sea‐level fall at the end of Palaeozoic that offered an opportunity for lateritization process. [ABSTRACT FROM AUTHOR]

Continental‐scale shear zones in Indochina record Cenozoic tectonic processes in SE Asia. Previous extrusion models link these shear zones to northward indentation of the Indian continent and conflict with distributed Oligocene conjugate strike‐slip pairs, formed by E‐W‐directed compression (present coordinates). This paper presents evidence of Oligocene shearing along the Mogok Metamorphic Belt in Myanmar, the western boundary of the Indochina block. The Kyanigan quarry at northern Mogok Metamorphic Belt exposes paragneiss, marble and quartzite schist with E‐W striking, which would be dragged from N‐S striking foliations of the main Mogok Metamorphic Belt by right‐lateral shearing of the brittle Sagaing Fault. After restoration, right‐lateral shearing 'σ' structures, cored with garnet, in paragneiss in the Kyanigan quarry are consistent with 'σ' and 'δ' structures in the Moulmein granitic mylonite to the south. U–Pb ages of metamorphic zircon of a sheared paragneiss and a leucogranite, cross‐cutting shear foliation in the Kyanigan quarry, and a biotite 39Ar‐40Ar age of mylonite at Moulmein constrain dextral shearing to 33–25.4 Ma, coeval with other 31–24.5 Ma shear zones in Indochina. The eleven NW‐striking left‐lateral shear zones and N‐S to NE‐striking right‐lateral shear zones define Oligocene conjugate fault patterns in Indochina. After restoration of ~80–45° clockwise rotation, these Oligocene conjugate shear zones, coupled with the anticlinal configuration of the Xuelongshan and Doi Inthanon‐Doi Suthep domes, reflect approximate N–S‐directed shortening. These structures to the north with coeval Myanmar‐Sumatra magmatic arc to the south demonstrate that they correspond to back‐arc contraction during northward subduction of the Indian Ocean. Oligocene continental‐scale intra‐continental shearing may be triggered by syn‐subduction compression in SE Asia. [ABSTRACT FROM AUTHOR]