用近垂直方法提取莫霍面——以六盘山深地震反射剖面为例  

Extracting the Moho structure of Liupanshan by the method of near vertical incidence

作　　者：李洪强[1,2] 高锐[1,2] 王海燕[1,2] 李文辉[1,2] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]国土资源部深部探测与地球动力学重点开放实验室(建),北京100037

出　　处：《地球物理学报》2013年第11期3811-3818,共8页Chinese Journal of Geophysics

基　　金：国家专项项目"深部探测技术试验与集成"(SinoProbe-02);中国地质调查局地质调查工作项目(1212011220260;1212011120975;1212010811051);国家自然科学基金(40830316)联合资助

摘　　要：根据近垂直地震反射原理和Moho面上下深地震反射资料频率低的特征,运用深地震反射资料的近垂直反射数据,通过静校正、资料净化、共检波域叠加等叠前和叠后处理技术,对六盘山莫霍面结构进行成像.初步结果显示出横过六盘山莫霍面起伏、断错的结构特征.六盘山东侧的鄂尔多斯地块莫霍面东高西低、变化平缓、结构完整;靠近六盘山前缘莫霍面错断,可能与壳内走滑作用有关;西侧的青藏高原东北缘莫霍面西高东低,靠近六盘山呈现汇聚挤压、明显缩短的特征;六盘山复杂的莫霍面结构,揭示了六盘山地壳早期双向挤压、晚期山前侧向走滑的构造图像.Based on near-vertical reflection principle and the low frequency characteristics of the data, the Moho depth variation along the survey line across Liupanshan Mountain was observed by using deep seismic reflection. For obtaining the profile, a series of processing techniques including both pre-stack and post-stack have been used, such as statics, denoising, stack in common receiver domain and so on. There are both undulating and offsets of the depth of Moho along the survey. The depth of Moho beneath the Ordos block, which lies to the east of Liupanshan Mountain, becomes deeper from east to west with gentle undulations. The offset of Moho close to the eastern frontier of the Liupanshan Mountain may be caused by the strike- slipping of the crust. The depth of Moho beneath the northeastern margin of Qinghai-Xizang plateau becomes deeper from west to east and indicates the features caused by convergence and shortening in this area. The complex structure of Moho along the survey revealed the characteristics of compressing from two opposite sides followed by lateral strike-slipping of the crust.

关 键 词：六盘山 青藏高原东北缘 鄂尔多斯地块 莫霍面 近垂直反射 深地震反射 

分 类 号：P315[天文地球—地震学]