晚中生代太平洋板块俯冲对华北克拉通破坏的影响：来自古地磁学研究的约束

Destruction mechanism, process and dynamics are keys to understand the North China Craton (NCC) destruction. It has been recently demonstrated through seismic, geochemical and tectonic studies that the paleo-Pacific plate (e.g. Izanagi plate) subduction is probably the major driving force led to the NCC destruction. In this project, we plan to carry out paleomagnetic investigations on the NE China and SE Korea peninsula, which are expected to response to the subduction and record the subduction process. We will also compile and compare available published Late Mesozoic paleomagnetic data obtained from E China, Korea peninsula and Japan Island, in order to further analyze the regional tectonic movement patterns, if there is any, during Late Mesozoic period. The aim of this project is, from the paleomagnetism point of view, to assess the possible links between the paleo-Pacific plate subduction and the NCC destruction.

最新的地震学、地球化学、盆地和构造学综合分析已揭示出晚中生代太平洋古板块俯冲是华北克拉通破坏的主要动力因素。确定太平洋板块俯冲对于华北克拉通破坏的影响，厘定东亚地区的浅部构造响应是关键。东亚陆缘构造变形过程可能与太平洋古洋壳俯冲作用有关，因此研究东亚陆缘构造变形记录是反演古洋壳俯冲的重要途径之一。本项目拟选择东北小兴安岭-张广才岭和韩国东南部晚侏罗世-白垩纪地质剖面开展古地磁学与年代学研究，分析东亚地区（我国东部、朝鲜半岛及日本岛）晚中生代古地磁学数据及其构造含义，通过分析东亚陆缘构造活动及规律，帮助厘定太平洋板块俯冲作用对华北克拉通破坏的贡献，为认识华北克拉通破坏机制提供新的证据。

项目针对太平洋板块俯冲对华北克拉通破坏潜在影响的关键科学问题，选择中国小兴安岭－张广才岭地区和韩国Gyeongsang盆地开展晚侏罗世－白垩纪地层/岩石的古地磁学研究，获得了上述地区古地磁研究的新数据，并对中国东部、朝鲜半岛已有古地磁数据进行综合分析，发现中国东部和朝鲜半岛该时期古地磁结果表现为相似特征，如古地磁偏角随时间变化具有相似性，发映出研究地区块体的在晚中生代的构造旋转运动具有较一致行为，指示东亚东缘构造运动可能受到古太平洋俯冲运动影响而发生了调整。