Organic-inorganic interactions of clay minerals and organic matter: Action mechanism and analysis techniques

Elucidating the formation mechanism of organic-rich shale holds significant implications for hydrocarbon exploration, carbon sequestration, and carbon cycling. In recent years, the relationship between organic matter and clay minerals in shale has attracted widespread attention. This study aims to comprehensively overview the interactions between organic matter and clay minerals during deposition and diagenesis. Through sedimentation processes, climate and provenance control the composition of clay minerals in sediments jointly. Meanwhile, clay minerals exhibit selective adsorption of organic matter, thereby influencing the abundance and type of organic matter in sediments. In modern marine depositional environments, the interaction between clay minerals and organic matter significantly impacts the overall activity and burial efficiency of organic carbon. During the diagenesis stage, the presence of organic matter dramatically affects the transformation of smectite into illite. Conversely, the process of smectite illitization also exerts a significant influence on hydrocarbon generation. Furthermore, this study introduces state-of-the-art techniques to investigate the interactions between organic matter and clay minerals.