松辽盆地晚白垩世烃源岩活性铁埋藏记录与生物地球化学效应

The oil and gas resources of China are mainly from terrestrial source rocks while the it is still not well-understood for the genesis of terrestrial source rocks. The burial of reactive iron had regulated or controlled the organic carbon burial in the marine sediments as indicated by the studies of recent years. This project will investigate the reactive iron burial records and their effects on the formation of terrestrial source rock of Songliao Basin. Multidisciplinary study, including sedimentary geochemistry, mineralogy, paleontology and cyclostratigraphy, will be conducted in the project.The reactive iron burial records of the source rock will be acquired to explore the fluctuation of redox conditions of bottom water in the paleo-lake. By combination of reactive iron data with that of other elements such as sulfur and phosphorus, both coupling and decoupling of iron, sulfur and phosphorus cycle will be examined to elucidate relationship between geochemical cycles and the formation of terrestrial source rock of Songliao Basin. This work will be of significance in developing the Chinese theory of continental oil generation.

陆相烃源岩提供了我国主要的油气资源，但是其成因机制研究还显得尤为薄弱。近年来对海相烃源岩成因机制的研究表明，海洋沉积物中活性铁的埋藏，对海相烃源岩中有机碳的埋藏起到了重要的调节和控制作用。本项目选择年代控制较好的松辽盆地晚白垩世陆相烃源岩为研究对象，进行分米/厘米级间距采样，结合现代分析技术，开展以沉积地球化学为主，矿物学、古生物学和旋回地层学为辅的多学科研究，获取松辽盆地烃源岩高分辨率活性铁埋藏记录，恢复烃源岩沉积时期湖泊底层水氧化还原变化；同时结合该烃源岩的磷和硫地球化学资料，探讨活性铁埋藏形式的变化对湖泊中磷循环的影响，并在此基础上探讨其对松辽盆地陆相烃源岩形成的贡献，为丰富和发展我国"陆相生油"理论服务。

陆相烃源岩提供了我国主要的油气资源，但是其成因机制研究一直薄弱。项目执行过程中主要对松科1井烃源岩进行了活性铁以及相关的沉积地球化学分析，并利用松科2井岩心进行了重点开展了对嫩江组一二段的岩心扫描数据的气候旋回分析，对碳-铁-硫等地球化学元素耦合关系对米兰科维奇旋回的响应做了重点探索，发现只有当海侵程度适当的条件下，才有利于有机碳的埋藏；海侵程度的提高可能造成湖泊对流的增加，从而不利于优质烃源岩的形成。同时发现嫩江组一二段沉积时期西风带和季风的相互作用是控制陆源区气候变化的主要因素，而且通过岁差对季风的调节实现对元素间相互循环的控制。预计成果对丰富和发展我国的“陆相生油”理论，和白垩纪陆相古气候研究，都具有重要的意义。