由于缺乏具备全球界线标志性对比的菊石化石，国际侏罗系/白垩系界线至今尚未确定。藏南发育连续沉积的海相侏罗-白垩系地层，围绕菊石、双壳类、有孔虫、钙质超微化石等生物地层学为主的界线研究取得了诸多成果，但全球界线层型剖面和层型点（金钉子）尚有待确定。申请者多年来从事藏南侏罗/白垩系界线研究，实测20余条剖面并采集了大量的样品，在多条剖面发现钙质超微、菊石等化石。本课题拟以羊卓雍措周边江孜、浪卡子和贡嘎等地典型实测剖面的研究样品为依托，以高分辨率微体生物（钙质超微化石、翁虫类）地层学研究为核心，重点寻找具有界线识别意义的微体化石，以菊石、箭石生物地层学研究为补充，结合地球化学研究，确定侏罗/白垩系界线位置，进而探讨界线时期古海洋环境演化，综合解析侏罗/白垩纪之交研究区生物地层所蕴含的与古海洋演化相关的信息，为国际侏罗/白垩系界线的划分，以及全球金钉子的确定提供研究数据。

Due to the lack of landmark ammonite fossils with iconic global boundary correlation，the international Jurassic/cretaceous boundary has not yet been determined. The Jurassic to Cretaceous marine strata have been deposited continuously in southern Tibet, and many achievements have been made around the boundary of biostratigraphy, such as ammonite, bivalves, foraminifera, calcareous nannofossils and so on. But the global boundary stratotype sections and points (GSSP) remains to be determined. The study of the Jurassic/cretaceous boundary in southern Tibet has been engaged in for many years. More than 20 sections have been measured and a large number of samples have been collected. The calcareous nannofossils and ammonite have been found in the several sections. This project intends to rely on the research samples of typical measured sections in Gyangze, Nagarze and Gongga around Yangzuoyong Co Lake, focused on the high resolution micropaleontology (calcareous nannofossils, calpionellids) stratigraphy research, the key finding boundary identification significance of microfossil, with ammonite and Belemnite biostratigraphic study for complement, in combination with geochemical research, the Jurassic/cretaceous boundary position is determined. And then the evolution of paleoceanographic environment during the boundary period will be discussed, and the biostratigraphic information related to the paleoceanographic evolution in the study area during the Jurassic/cretaceous boundary period will be comprehensively analyzed, so as to provide research data for the division of the international Jurassic/cretaceous boundary and the determination of the GSSP.