日本海打开的时间与机制一直是东北亚大陆边缘新生代演化研究的关键科学问题之一，然而，对日本海打开的深部作用过程研究是一个薄弱环节。本项目拟选择北海道西侧奥尻岛发育的新生代始新世-上新世火山岩作为研究对象，通过系统的年代学、岩石学以及岩石地球化学研究，查明奥尻岛新生代火山作用的时空格架与岩石组合；通过元素-同位素地球化学示踪技术（尤其是Sr-Nd-Pb-Hf-Mg同位素组成），确定奥尻岛新生代不同期次火山作用的岩浆源区性质及其随时间演化；结合区域地质与地球物理研究成果，最终揭示奥尻岛新生代火山作用深部过程与日本海打开之间的成因联系。该项研究对于揭示东北亚陆缘新生代构造属性转换的时间与机制具有重要意义。

The timing and mechanism of the Japan Sea opening is one of the key scientific problems in studying the Cenozoic tectonic evolution in NE Asian continental margin, however, the study about the deep processes of the Japan Sea opening is a weak link. This project takes the Eocene-Pliocene volcanic rocks in the Okushiri Island, west side of the Hokkaido, as the research object. We try to ascertain the spatial-temporal framework and rock association of the Cenozoic volcanism in the Okushiri Island through an integrated study of geochronology, petrology and geochemistry, determine the magma source properties and their evolvement with time of the Cenozoic different stages of volcanism in the Okushiri Island based on the elemental and isotopic tracer techniques (particularly in Sr-Nd-Pb-Hf-Mg isotopic compositions), and finally reveal the genetic connection of deep processes of the Cenozoic volcanism in the Okushiri Island and the opening of the Japan Sea combined with the research results of regional geology and geophysics. This project is of important implication for revealing the Cenozoic tectonic transformation timing and mechanism in NE Asian continental margin.