海底冷泉系统氧化还原环境重建方法研究进展

Research progress on reconstruction method of redox conditions in submarine seafloor cold seeps

冷泉活动是现代深海极端环境系统之一,其在天然气水合物资源勘探、全球气候变化、极端环境生命活动等方面具有重要的科学研究意义。重建海底冷泉区氧化还原环境是研究其中生物地球化学过程、揭示甲烷渗漏活动特征的重要途径。近年来,大量矿物学及地球化学指标在冷泉系统氧化还原条件的恢复研究中获得了成功的应用。在前人研究的基础上,对自生矿物学标志、稀土元素、氧化还原敏感元素(Mo、U、Fe)和稳定同位素(钼同位素δ^(98)Mo、铁同位素δ^(56)Fe、硫同位素δ^(34)S)等不同指标对氧化还原环境变化的响应机制进行了系统总结,从测试分析方法、后期成岩改造、单一指标的多解性等多个方面探讨了各指标的影响因素和当前仍存在的问题,并指出了未来该领域需进一步加强的关键研究方向。

Cold seep is one of the seafloor extreme environmental systems,it has important scientific significance in gas hydrate exploration and global climate change for extreme environmental life activities.Reconstruction of redox conditions in cold seep is an important way to study the biogeochemical processes and reveal the characteristics of methane seepage.In recent years,many mineralogical and geochemical indicators have been successfully used in the study of the recovery of redox conditions in cold seep systems.Based on previous studies,the responding mechanisms of different redox indicators were summarized,such as autogenetic mineralogical characteristics,rare earth elements,redox sensitive elements(Mo,U,and Fe),and stable isotopes(δ^(98)Mo,δ^(56)Fe,andδ^(34)S).The influencing factors and existing issues of each index were discussed from the aspects of test and analysis methods,diagenetic alteration,and non-uniqueness in using a single index.At last,the key research direction in this field in the future was proposed.