白垩纪大洋缺氧事件是极端温室气候影响下全球碳循环扰动的重要体现，对该事件的研究也是了解温室气候变化的关键契机。松辽盆地嫩江组作为白垩纪大洋缺氧事件陆相响应，对其研究已取得显著进展，但有关氮的生物地球化学过程关注较少，同时对于极端温室气候的形成机制的认识还不透彻。申请者前期通过松辽盆地大陆钻孔样品对嫩江组的生物地球化学特征进行过定性研究，发现反硝化作用导致的N2O脱气很可能是该时期温室气体的重要的源。因此在前期基础上，本研究拟利用同位素具有记录生物地球化学过程信息的优势，通过高分辨率硝酸盐氮、氧同位素以及有机氮同位素分析，结合碳、总氮、硫同位素等数据，运用Rayleigh方程定量估算嫩江组沉积时期湖泊发生反硝化作用的程度，并加强气候变暖与反硝化过程在时间和地层上的精确对比，旨在提出白垩纪温室地球形成新机制。同时本研究成果也将使厌氧湖泊脱气作用的定性探讨进入定量重建的新高度。

The Cretaceous Oceanic Anoxic Event is an important response to the disturbance of the global carbon cycle under the influence of extreme greenhouse climate. The study of this event is also a key opportunity to understand the climate change of the earth. As the terrestrial response of the Cretaceous Oceanic Anoxic Event, remarkable progress of the Nenjiang Formation in the Songliao Basin has been made in research. However, the biogeochemical study of nitrogen is less, and the understanding of the formation mechanism of extreme greenhouse climate is not clear. In the past, we analyzed the qualitative study of the biogeochemical characteristics of the Nenjiang Formation through the drilling samples in the Songliao Basin and found that the N2O degassing caused by denitrification may be an important source of greenhouse gases during this period. Based on the earlier progress, this study uses the advantage of isotope that can record biogeochemical process to conduct the high-resolution analysis of inorganic nitrogen, oxygen isotope and organic nitrogen isotope. Combined with the total nitrogen, carbon and sulfur isotope data, we can use the rayleigh equation to quantitatively estimate the degree of denitrification in lakes during the deposition of the Nenjiang Formation, which is expected to strengthen the accurate comparison between climate warming and denitrification in time and strata and to put forward a new mechanism of the formation of Cretaceous greenhouse earth. At the same time, the research results will make the qualitative study of anaerobic lake degassing into a new height of quantitative reconstruction.