The characteristics and formation mechanism of clastic reservoirs have a significant impact on petroleum accumulation in the deep-seated strata of sedimentary basins. Newly drill data indicate that the tight reservoirs in the lower slop of Fukang Sag in the Junggar Basin produce a lot of oil despite being buried extremely deep and with low porosity. By using lithological and geochemical studies, we investigated the formation of these deep-seated reservoirs through the comparison between upper and lower slopes. The results suggest that the reservoir of lower slop is highly compacted and has weaker dissolution than the reservoir in the upper slope. Dissolution and micro fractures are the key factors in determining the formation of deep-seated reservoirs. The fluids that caused the dissolution of reservoir can be divided into three stages and sourced from the mixture of deep and basin fluids. A model of reservoir formation and evolution has been set up. Our research could provide an insight for the formation of deep-seated reservoirs in similar geological conditions worldwide.

Paleoenvironmental reconstruction plays a pivotal role in providing insights into the uplift history of the Xizang Plateau during the Cenozoic. The Nima Basin, situated in the central Xizang Plateau, is crucial for studying the tectonic and geomorphic evolution of this region. The clastic composition and geochemical characteristics of the Niubao Formation hold considerable potential for unravelling the geological history and reconstructing depositional environments of central Xizang in the early Cenozoic. In this study, we present detailed geochemical characteristics to determine their provenance, paleoenvironmental conditions, and tectonic origins. The index of compositional variability (ICV > 1) of mudstones indicates that low compositional maturity sediments underwent weak sedimentary recycling. The chemical index of alteration (CIA: 59.8−72.9) reveals that parental rocks experienced a moderate chemical weathering degree. The paleoclimate indicators of the mudstones suggest an oxidizing and arid depositional environment, with a mean annual temperature (MAT) of 11.64°C ± 4.19°C. The geochemical evidence also demonstrates that the mudstones were derived from mixed felsic and intermediate igneous rocks that formed in a dominantly continental island arc tectonic setting. Similarities in the geochemical characteristics among the Niubao Formation and surrounding igneous rocks indicate that a continental-scale drainage system once drained westward in central Xizang. It is concluded that the central plateau experienced a cooler and drier climate coinciding with the presence of a large-scale drainage system during the late Eocene.

This research focuses on analyzing land use and cover changes in Metropolitan Area of Wuhan between 1988 and 2023, utilizing a comprehensive data set from Landsat remote sensing and machine learning techniques to understand their implications for carbon storage. It finds that the Random Forest (RF) algorithm outperforms others like Support Vector Machine (SVM), Gradient Boosting Trees (GBT), and Classification and Regression Trees in identifying land use types, achieving high accuracy and a Kappa coefficient exceeding 0.98. Significant changes in Wuhan’s landscape have been noted, especially the marked decrease in arable land and increase in urban construction, reflecting the pressures of economic development and urban expansion on natural resources and their impact on the ecosystem. The study uses the InVEST model to assess how these land use transformations affect carbon storage, revealing a significant decrease in carbon storage from 1988 to 2023, with a total reduction of approximately 428.59 × 10⁴ t from 1988 to 2023, largely attributed to the conversion of key carbon sequestering lands such as arable lands and forests into urban areas. This transition, particularly from arable land to urban construction land, underscores the challenges faced in managing land use changes without compromising environmental sustainability and carbon storage capacities.

Aerosol-cloud interaction remains challenging due to the large uncertainties caused by the associated meteorological effects. This study examines the aerosol-warm cloud interaction over the cities of Bhubaneswar and Rourkela. A negative cloud effective radius (CER)-cloud optical depth and CER-cloud top pressure (CTP) relationship is found in all the regimes of aerosol optical depth (AOD) over Bhubaneswar and Rourkela, excluding CER-CTP association in heavy pollution scenarios over Rourkela. However, a significant positive CER-cloud water path (CWP) correlation is observed in all the cases of AOD over both cities. This can be attributed to strong competition between aerosol and cloud droplets for water vapor association. CER is found to increase with AOD in all the regimes of relative humidity (RH) over both cities, excluding low and high cases of RH over Bhubaneswar. In this scenario, enhanced collision and coalescence efficiency and increased water vapor content encourage the merging of smaller droplets, resulting in the growth in effective radius of clouds. Negative pressure vertical velocity (PVV) over these cities infers that the upward movement of the air parcels helps in the growth of cloud droplets and aerosol particles besides enhancing the cloud cover. The shift from the Anti-Twomey effect to the Twomey effect has been noticed in both urban areas, with the Twomey effect being the major influence. Overall results indicated aerosol-induced heating may increase the response of turbulent heat flux (sensible heat over the land), leading to enhanced stability at the lower troposphere and subsequent suppression of vertical mixing. It results in moisture trapping near the surface and increases warm clouds in Rourkela. However, the predominance of a positive semi-direct effect over Bhubaneswar leads to an adverse relationship between warm cloud cover and aerosols.

Subaqueous distributary channel sandbodies within delta fronts are crucial reservoirs in continental petroliferous basins. Understanding the spatiotemporal transition of river patterns in these channels is essential for accurate evaluation and prediction of oil and gas reservoirs, as well as for providing direct evidence of basin evolution. In the Yabus Formation of the Sag A of Melut Basin, a comprehensive analysis involving sequence division, sedimentary characteristics, seismic facies, high-resolution reservoir inversion, and sand body distribution revealed significant insights. During the Yabus Formation deposition, three intermediate base-level cycles were identified, each showing transition phenomena in the river patterns of subaqueous distributary channels within the delta front. Clear identification criteria for different river patterns were established. Braided subaqueous distributary channels exhibited dominant vertical accretion, high sand content, significant sandstone thickness, and continuous-strong amplitude seismic reflections. While the braided-meandering transition pattern showed a combination of vertical and lateral accretion, medium sand content, moderate sandstone thickness, and medium continuous-medium strong amplitude seismic reflections. Meandering subaqueous distributary channels were characterized by lateral accretion, low sand content, minimal sandstone thickness, weak continuous-weak amplitude seismic reflections, and mud-rich inversion features. The primary control factor influencing the transition of river patterns in these channels was identified as the long-term base-level cycle, shaped by paleotopography and sediment supply. Braided subaqueous distributary channels emerged as the main exploration interval for structural prospects, serving as lateral high-speed migration pathways. Dendritic braided and meandering transition intervals were deemed favorable for both structure-lithologic prospects and the expansion of new exploration fields and layers.

This study employed the three-dimensional MIKE model to simulate the hydrodynamic properties of Poyang Lake from October 2020 to December 2021. The model demonstrated high accuracy, with the coefficient of determination (R²) exceeding 0.96 for water level and 0.98 for water area comparisons, indicating its efficacy in replicating the lake’s hydrodynamics. Notably, the highest pressure gradient forcing was observed in March and April, aligning with increased flow rates in the Ganjiang River, affecting the east side of Poyang Lake. This period saw a distinctive pressure gradient front in the lake’s central channel, potentially influencing material distribution. Eddy kinetic energy, calculated from model velocity data, peaked in May and June, and again in September and October, corresponding to changes in river flow rates. This energy was predominantly influenced by local dynamics in the lake’s central area, with low frequencies and extended periods, differing from other lake regions. Furthermore, the study found a strong correlation between eddy activities and the spatial distribution of water materials, as indicated by the consistency of turbidity patterns in satellite imagery and eddy kinetic energy distributions. These findings highlight the significant impact of hydrodynamic behaviors, particularly eddy movements, on the distribution of suspended materials within Poyang Lake.

Ecological risk is a dynamic reflection of ecosystem stability and harmonious social development. The role played by risk identification and evolutionary trend prediction as mediators between ecological risk management and prevention is complex. However, current studies have difficulty identifying where, when, and how ecological risk evolves. Here, we constructed a double evaluation index system of ecological risk source hazard and ecological risk receptor loss degree to quantitatively evaluate and simulate ecological risk in the upper Chang Jiang (Yangtze R.) (UYR). Then, we adopted the normal cloud model to identify the ecological risk level at different scales in the UYR. Finally, we leveraged set pair analysis to reveal the future evolution trend of ecological risk in the UYR. The following conclusions were drawn. 1) From 2015 to 2018, the ecological risk in the UYR exhibited significant spatial aggregation characteristics, with a spatial distribution pattern of “high in the west, low in the east”. The risk value increased from [0, 0.28] to [0, 0.32], an increase of 12.49%. 2) The ecological risk level of the UYR in 2015 and 2018 was in a high-alert state, but the risk value showed a downward annual trend. The comprehensive ecological risk value decreased from 0.5295 to 0.5135. 3) The ecological risk of 67% of the cities in the UYR will decrease in the future, and will increase in 33% of the cities. 4) The probability of geological disasters was the most significant ecological risk source in the UYR. Ecosystem service value significantly impacted ecological risk receptors loss degree in the UYR.

The Xiuyan impact crater is the only officially recognized impact crater in China, and its formation time remains unclear. In this study, we investigated the ages of Xiuyan impact crater lake sediments from a 99-m composite borehole using luminescence and radiocarbon dating. The results showed that all the radiocarbon ages were saturated and that the surface sediments in the crater lake were dated to ~331–334 ka. Furthermore, the luminescence ages of lake sediments at depths below approximately 37 m also appear to be saturated. The evolutionary history of the Xiuyan impact crater lake was reconstructed by incorporating sedimentological, geomorphological, and geochronological analyses. Based on the age-depth model results of luminescence ages above a depth of 37 m, it is suggested that the crater lake underwent several stages: initial formation at approximately 1201 ± 133 ka, subsequent filling with water and sediment, overflow, and eventual disappearance at ~331–334 ka.

Unconventional natural gas in deep coal measures has become an exploration and research hotspot in recent years. The exploration breakthrough of deep coalbed methane and tight sandstone gas in Daning-Jixian Block in the eastern Ordos Basin has revealed huge resource potential and commercial prospects in the deep Upper Paleozoic Carboniferous-Permian coal measures. However, the ambiguity of gas accumulation in deep coal measures has restricted exploration and development. Based on a series of tests for fluid inclusions, including petrographic observation, Raman spectroscopy analysis, and microthermometry, combined with the burial-thermal evolution history recovered from basin modeling, this study aims to clarify the timing of gas accumulation in deep coal measures. The results show four types of secondary fluid inclusions in the deep coal measure sandstone layers of Daning-Jixian Block, including CH₄-rich inclusions, C₂₊ hydrocarbons-bearing inclusions, CO₂-bearing inclusions, and aqueous inclusions. The main formation stage of fluid inclusions corresponded to the mesodiagenesis stage of the deep coal measure sandstone, and the coeval assemblages of fluid inclusions vary due to the recording of gas charging in different maturity stages of coal measure source rocks. This study suggests that tight sandstone gas accumulation in deep coal measures was a continuous charging process with one period-multiple episodes in Daning-Jixian Block, and occurred mainly during the Early Cretaceous (137−127 Ma BP). The results of this study contribute to further understanding of gas accumulation mechanisms in deep coal measures.

Complex hydrocarbon distributions characterize the Wenchang-A Sag. Systematic study of the geochemical characteristics of crude oil, natural gas and source rocks and their genetic relationship is still needs to be completed. The Rock-Eval, kerogen maceral, vitrinite reflectance, saturated hydrocarbon gas chromatography-mass spectrometry, natural gas components, carbon isotopes, and light hydrocarbon were performed. 1) Crude oil is classified based on four factors: wax content, the presence of C₂₇ diasteranes, the regular steranes αα20RC₂₇-αα20RC₂₈-αα20RC₂₉, and the bicadinanes characteristics. Class I crude oil has high wax and C₂₇ diasteranes. For Class II crude oil, the regular steranes are in ‘L’- shaped distribution, and the content of bicadinanes is shallow. Class III crude oil has soft wax and C₂₇ diasteranes, and regular steranes in the reverse ‘L’-shaped distribution, with a high peak degree of bicadinanes. For Class IV crude oil, regular steranes are in ‘V’-shaped distribution, with high peak bicadinane. 2) Class I crude oil comes from source rocks in area C. Class II crude oil comes from source rocks in areas D and E. Class III crude oil comes from areas A, and B. Class IV crude oil comes from source rocks in area A. 3) The source of natural gas in Group I is hydro propylene, and natural gas in Group II is humic. Natural gas in Group III is mixed. Groups I and II are kerogen cracking gas, and group III is a mixture of crude oil secondary cracking gas and kerogen cracking gas. Natural gas in Groups I and II mainly come from local source rocks, and Group III has mixed source characteristics. In the future, oil exploration can continue in Areas C and D, and more favorable areas for gas exploration are Areas C, D, and E.