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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]

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]

Organic‐rich shale in saline lacustrine basins holds significant importance as a source rock for conventional hydrocarbon exploration and has emerged as a prominent target for unconventional hydrocarbon exploration and development in recent years. Based on saline lacustrine basins, this paper provides a summary of the organic matter enrichment mechanisms in saline lacustrine basins, considering sedimentary characteristics, biological activities, factors for the organic matter enrichment and consumption, and hydrocarbon generation. The implications for these factors are discussed in relation to the distribution prediction of high‐quality lacustrine shale district settings and the exploration and development of shale oil. Saline lacustrine basins undergo distinct evolutionary stages, each corresponding to different sedimentary stages involving carbonate minerals, sulphate minerals, and alkaline minerals. Moreover, these basins exhibit diverse biological types and experience extensive biological activities. The prosperity of organisms and the accumulation of sedimentary organic matter are ensured by halophilic organisms. Organic matter enrichment in saline lacustrine basins is influenced by two main aspects: the primary productivity of organic matter, which is promoted by the proliferation of halophilic organisms, and the efficient preservation of organic matter facilitated by the strong reducing environment resulting from promoted water salinity stratification. The organic matter consumption in saline lacustrine basins involves bacterial sulphate reduction (BSR) in the early stages, thermochemical sulphate reduction (TSR) in the late stages, and dilution of salt minerals with higher depositional rates. of the presence of salt beds and saline minerals positively influences hydrocarbon generation and expulsion in organic‐rich shale within saline lacustrine deposition. Consequently, continental saline lacustrine basins in China offer favourable conditions for the formation of organic‐rich shale and present broad prospects for the exploration of shale oil and gas resources. [ABSTRACT FROM AUTHOR]