The 37thInternational Meeting of Sedimentology (also referred to as the 37th IMS) was held in June 2024 in Aberdeen, UK, focusing on the frontiers of sedimentology. Specifically, this meeting highlighted cutting-edge academic issues including the interactions between the Earth, life, and climate, Precambrian environments, source-to-sink systems, fluvial and lacustrine sedimentation, tidal action and neritic sedimentation, deep-water sedimentation, and the diagenesis and reservoir characterization of siliceous clastic rocks. Additional focal areas included carbonate rocks and evaporites, ichnology, volcanoes and geochemistry, planetary sedimentology, geothermal resources and energy transition, seismic sedimentology, and AI-based new methodologies and technologies for sedimentological research. This meeting emphasized the importance of paleoclimate research in deciphering deep-time global changes, presenting a novel approach to reconstruct paleoclimate using high-resolution sedimentary records. It underscored the coupling relationships among tectonic activities, climate change, and sedimentary processes, positing that elucidating source-to-sink transport mechanisms necessitates multi-scale geomorphological reconstruction and sediment flux simulations. Furthermore, this meeting underlined the transport and deposition mechanisms of fine-grained sediments in deep-water environments, and introduced novel machine learning-based methods for automatic sedimentary facies identification, reservoir prediction, and sedimentary process simulation. A comprehensive analysis of the cutting edge obtained from the 37th IMS reveals that future sedimentological research in China should prioritize research on paleoclimate and deep-time global changes, paleogeomorphology and source-to-sink systems, deep-water sedimentation and fine-grained sedimentology, and new technologies such as big data and AI. The purpose is to achieve the national energy strategic objectives and establish a sedimentological theoretical system that reflects the regional geological characteristics of China.

The sedimentary environments of fine-grained sediments and the spatio-temporal distribution patterns of the fine-grained lithofacies are identified as primary factors governing the enrichment and high yield of shale oil. Starting from previous relevant studies, we investigate the sedimentary environments and primary characteristics of fine-grained sediments in typical continental basins in China, including the Songliao, Bohai Bay, Ordos, and Junggar basins. The findings suggest that: (1) Fresh-to-brackish-water lacustrine basins typically contain claystones, siltstones, and transitional lithologies between them, showing the presence of silty, clayey, and organic laminae. In contrast, the lagoon and saline lakes mostly develop fine-grained carbonate rocks and mixed fine-grained sedimentary rocks, characterized by calcite (dolomite) laminae and the laminae of clayey marls. (2) Different evolutionary stages of continental basins developed the occurrence of varying assemblages of fine-grained lithofacies. Fine-grained sedimentary rocks formed during rifting are characterized by lithofacies assemblages rich in carbonate minerals, while organic-rich shale layers formed during depression are dominated by the assemblage of feldspathic and clayey sedimentary rocks. (3) Primary mechanisms for shale deposition in lacustrine basins include suspension settling, aeolian input, turbidity flows, hyperpycnal plumes, and muddy debris flows. (4) Continental shale oil in China exhibits diverse types. It boasts abundant resources in the Mesozoic-Cenozoic continental basins such as Songliao, Ordos, Junggar, and Bohai Bay basins serving as important targets for shale oil exploration and exploitation. (5) Future research on the sedimentary settings and lithofacies of fine-grained sediments should be focused on astronomical cycles to establish systematic and effective parameters and criteria for identifying paleosedimentary environments. Furthermore, it is essential to develop classification schemes and sedimentary models for the fine-grained sedimentary lithofacies of shale, interbedded, and mixed types in continental basins to effectively predict the spatio-temporal distributions of these lithofacies. Physical and numerical simulations of the sedimentary origin and processes of fine-grained sediments are recommended to examine the sediments' coupled physical, chemical, and biological depositional processes, as well as its formation and development mechanisms. Additionally, it is necessary to pay attention to data integration, in-depth data mining, artificial intelligence (AI), big data, and computer aided technology to investigate the distribution patterns of fine-grained sediments.

The controlling factors of organic-rich shale accumulation is essential for the exploration and development of shale oil and gas resources. The sedimentary environment plays a vital role in the formation of organic-rich sediments in lacustrine facies. This article unravels the mineralogy, geochemistry, and paleoenvironmental evolution during the deposition of the Paleogene Shahejie Formation (Es₃^L). It discusses the effects of paleoclimate, paleosalinity, paleoredox conditions, paleowater depth, and paleoproductivity on organic matter (OM) enrichment. Finally, the OM enrichment model was established. The results show that the mineralogical compositions are mainly composed of calcite (avg. 40.13%), quartz (avg. 21.64%) and clay minerals (avg. 24.07%), accompanied by dolomite (avg. 7.07%), feldspar (avg. 6.36%) and pyrite (avg. 2.95%). The Es₃^L shale has a high abundance of OM, with total organic carbon (TOC) ranging from 1.07% to 5.12%. The organic matter type is mainly composed of type Ⅰ-Ⅱ₁ kerogen, which is generally considered a good-quality source rock. The source of OM is a mixture of lower bacteria, algae, and plants. During the early sedimentary period, the paleoclimate was dry and cold, with high salinity, intense reducibility, and relatively low productivity. During the late sedimentary period, the climate became warmer and more humid. As a result, the salinity decreased to a level that was suitable for biological reproduction, and productivity increased gradually due to the input of terrigenous plants. Paleosalinity and paleoclimate determined the environment of the sedimentary period, in addition, paleoproductivity and paleoredox condition indicated the formation and preservation conditions of OM. The warm and humid climate, brackish water, suitable reduction conditions and high productivity are the favorable conditions for the generation and preservation of organic matter. The research results may have implications for the genetic mechanisms of organic matter accumulation. They will provide theoretical and technical insights into the exploration and development of shale oil.