扬子块体与华北块体在海区的接触关系——来自上下源、长排列多道地震剖面的新认识  

Contact relationships between the North China block and the Yangtze block:New constraints from upper/lower-source and long spread multi-channel seismic profiles

作　　者：吴志强[1,2,3] 郝天珧[4] 张训华[1,2,3] 刘丽华[4] 肖国林[1,2,3] 温珍河[1,2,3] 

机构地区：[1]青岛海洋科学与技术国家实验室海洋矿产资源评价与探测技术功能实验室,青岛266000 [2]国土资源部海洋油气资源与环境地质重点实验室,青岛266071 [3]青岛海洋地质研究所,青岛266071 [4]中国科学院地质与地球物理研究所,北京100029

出　　处：《地球物理学报》2015年第5期1692-1705,共14页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41210005;41174098);国土资源部地质调查专项(GZH201200509)联合资助

摘　　要：在新一轮南黄海区域地质地震调查工作中,针对地震地质条件和勘探目标,设计了新的地震资料采集技术方案——上下源延迟激发+长排列接收,获得了强反射界面之下的深部地层有效反射,揭示了千里岩断裂两侧分布着向南逆冲的构造推覆带.结合重力、磁力反演成果认为,千里岩隆起区为扬子块体与华北块体碰撞接触带,扬子块体向北运动与华北块体碰撞后楔入到华北块体之中.Many geologists have studied the contact of the Yangtze block and North China block in the sea area with regional geological and geophysical methods.There are still different understandings.Combining regional geological data,we analyzed the contact relationships between these two major tectonic blocks in the sea area by acquisition,processing and analysis of multi-channel seismic data in the South Yellow Sea. According to the seismic geological conditions and exploration target,we designed a new air-guns array pattern of upper/lower sources which can effectively attenuate the effect of ghost in the low frequency range,broaden the bandwidth of seismic signal and promote the energy of low frequency components,based on theadvantage of the large penetration depth and long pathways for low frequency signal.For the exploration target layer of weak seismic reflection characteristics,we used long cable method receiving strong wide-angle reflection signal.The long spread of wide-angle reflection receiving method was used considering poor reflection in the target layer interiors,which permitted to achieve the strong energy wide-angle reflection at the large offset.The time-distance curve of wide-angle reflection with large offset is clear non-hyperbolic,which is difficult to focus on the effective stack data.We adopted the normal moveout correction of wide-angle reflection which was based on the anisotropic and the pre-stack time migration processing to achieve the impactful NMO,stacking and imaging of wideangle reflection.We obtained the deeper effective reflection that was below the continental sedimentary layer with the application of new seismic exploration technology.According to the seismic reflection characteristics and the regional geological background,the seismic reflection events in the southern Yellow Sea basin can be divided into four seismic reflection sequences in the new seismic imaging section.There are the Cenozoic continental facies seismic reflection sequence（S1）,Mesozoic continental facies seismic

关 键 词：扬子块体 华北块体 接触关系 新认识 

分 类 号：P631[天文地球—地质矿产勘探]