白垩纪超静磁期是“深时”时期全球重大地质事件之一，该超静磁期的结束被认为是白垩纪Santonian-Campanian界线的全球可识别的主要标志，但目前对该超静磁期的结束年龄还存在争议。"松辽盆地大陆科学钻探"获取了近乎连续的上侏罗统-白垩系岩心，前期的综合年代学研究结果表明嫩江组二段记录了白垩纪超静磁期的结束，为高精度约束白垩纪超静磁期的结束年龄提供了绝佳的研究素材。本研究拟利用“松辽盆地大陆科学钻探”获取的连续的岩心材料，对松科2井嫩江组一、二段的火山灰夹层开展单颗粒锆石U-Pb CA-ID-TIMS高精度地质年代学研究，为旋回地层学提供高精度绝对年龄锚点，建立松辽盆地上白垩统嫩江组高精度、高分辨率年代标尺。在此基础上，为白垩纪超静磁期的结束提供高精度年龄约束，同时完善松辽盆地晚白垩世年代格架。

The Cretaceous Normal Superchron (CNS) is one of the major geologic events in deep time. The termination of the CNS, which could be globally recognized, is considered as the best definition for the Santonian-Campanian boundary. However, the age of the end of the CNS is still under debate. The Continental Scientific Drilling Project (SKI and SKII) in Songliao Basin recovered near continuous successions from the Upper Jurassic to Cretaceous. Previous integrated geochronologic study suggested the geomagnetic polarity reverse in Member 2 of Nenjiang Formation represented the end of the CNS, and thus making the Songliao Basin as the excellent candidate to precisely constrain the age of the termination of the CNS. In this study, we plan to apply high-precision zircon U-Pb CA-ID-TIMS geochronology on the interbedded bentonites from the Nenjiang Formation of SKII to establish a high-precision absolute age framework, which could serve as high-precision anchor points for cyclostratigraphy and establish a high-precision and high-resolution geochronologic timescale. With this timecale, we could precisely calibrate the age of the termination of the CNS and improve the late Cretaceous age model of the Songliao Basin.