【作者】 钟广见；

【导师】 刘大锰； 姚艳斌；

【作者基本信息】 中国地质大学（北京） ， 矿产普查与勘探， 2014， 博士

【摘要】 南海是西太平洋中面积最大的边缘海，处于印度-澳大利亚板块、欧亚板块和太平洋-菲律宾海板块相互作用的关键部位，又是地质历史上太平洋构造域与特提斯构造域的结合部。作为西太平洋边缘海的典型代表，南海经历了从大陆边缘裂解到最终的海底扩张演化的过程，西北次海盆形成的形成机制与南海扩张密切相关。本文通过厘定西北次海盆内沉积充填地层时代，分析研究新生代构造变形特征和沉积特征变化规律，认为西北次海盆接受了晚渐新世以来的沉积；海盆北边的陆坡则沉积了始新世以来的沉积。分析构造-沉积特征与海盆扩张过程之间的响应关系，提出西北次海盆新生代演化模式--南海西北次海盆经历了大陆裂解期、大洋扩张期和后大洋扩张期三期构造演化；西北次海盆与南海中央海盆同时期扩张。取得如下成果：①西北次海盆接受了晚渐新世以来的沉积；海盆北边的陆坡则沉积了始新世以来的沉积。海盆内的沉积层可以追踪识别7个地震反射界面，自上而下分别为S1.8（T2）、S5.5（T3）、S10.5（T4）、S16.4（T5）、S23.3（T6）、S28.0（T7）。②南海西北次海盆的构造演化分为大陆裂解期、大洋扩张期和后大洋扩张期。③西北次海盆与南海中央海盆同时期扩张。更多还原

【Abstract】 South China Sea（SCS） is the largest marginal sea in the western Pacific. In thestructure，it locates in intersection of India_Australian Plate,Eurasian Plate andPacific_Philippine Sea plate.On the geological history,it located in the junction of thePacific tectonic domain and Tethys tectonic domain. As a typical marginal sea in thewestern Pacific, SCS experienced the whole evolution from continental margin splitto seafloor spreading.By determining the sedimentary age of sea basin in the northwest SCS, this paperanalyses Cenozoic tectonic deformation and sedimentary characteristics. Thenorthwest sub-basin of SCS deposited from late Oligocene, but the slop of thesub-basin deposited from Eocene. By analyzing response relationship betweensedimentary and seafloor spreading, Cenozoic evolution model was proposed.Thesub-basin underwent three structure evolution,continental margin split-seafloorspreading and past seafloor spreading.Achieved the following results.①Northwest sub-basin accepted the deposition since the lateOligocene; but the North slope of the sub-basin accepted thedeposition since Eocene. Seven seismic reflectors can be traced,from top to bottom respectively S1.8(T2), S5.5(T3), S10.5(T4),S16.4(T5), S23.3(T6), S28.0(T7)。②The sub-basin underwent three structure evolution,continental marginsplit-seafloor spreading and past seafloor spreading③The seafloor spreading of sub-basin started at the same time with centerbasin of SCS.更多还原