摘要
作为一种能够精细揭示地球深部地质结构及构造特征的有效手段,深地震反射剖面技术目前已越来越多地应用于大陆及海洋地壳与岩石圈上地幔的探测中,被国际公认为地球深部探测的先锋技术。以横跨河北雄安新区的深地震反射剖面为研究对象,旨在揭示研究区的地壳结构与构造特征。结果表明:(1)该地区地壳可分为上地壳和下地壳两部分,上地壳平均厚度约18 km,下地壳平均厚度约16 km,莫霍面平均深度约34 km。(2)上地壳内,结晶基底以上的沉积地层成层性好、地层反射能量强、结构特征复杂,断裂构造较发育、形态各异、错断深度不同、无深大断裂,主要断裂自SE向NW依次为牛东断裂、牛北断裂、容东断裂、容城断裂、容西断裂以及太行山山前断裂。(3)下地壳内,深地震反射剖面西北部和东南部受到不同构造应力作用,西北部和中部相对“透明”,反映雄安新区整体构造较为稳定;东南部存在较强的“叠瓦状”反射特征,反映下地壳横向非均质性和局部活跃的特征。上述研究为雄安新区总体规划与建设和构建万米“透明雄安”基础平台提供了可靠的数据支撑。
As an effective method to accurately reveal the deep geological structures and tectonic features of the Earth,deep seismic reflection profiling has been increasingly applied to the exploration of the continental and oceanic crusts,as well as the upper mantle of the lithosphere,making it internationally recognized pioneer technique for deep Earth exploration.This study examined the deep seismic reflection profile spanning across the Xiong’an New Area in Hebei Province,aiming to reveal the crustal structure and tectonic features of the study area.Key findings are as follows:(1)The crust in the study area can be divided into the upper and the lower crusts,with average thicknesses of approximately 18 km and 16 km,respectively and an average Moho depth of around 34 km.(2)In the upper crust,the sedimentary strata above the crystalline basement exhibit high stratification,strong reflected energy,and intricate structural characteristics.Faults are well-developed in the upper crust,exhibiting various morphologies and dislocation depths,with no deep-seated faults.The major faults encompass the Niudong,Niubei,Rongdong,Rongcheng,and Rongxi faults and the Taihang Mountain piedmont fault from southeast to northwest.(3)In the lower crust,the northwestern and southeastern portions of the deep seismic reflection profile are subjected to different tectonic stresses.Consequently,the northwestern and central segments manifest relatively simple seismic reflection features,reflecting relatively stable overall tectonics in the Xiong’an New Area.In contrast,the southeastern segment of the profile exhibits pronounced imbricate reflections,mirroring the lateral heterogeneity and local activity of the lower crust.These results will provide reliable data support for the overall planning and construction of the Xiong’an New Area and for the building of geological information platform Transparent Xiong’an,which involves survey depths of 10000 m.
作者
岳航羽
王凯
王小江
张保卫
张凯
YUE Hangyu;WANG Kai;WANG Xiaojiang;ZHANG Baowei;ZHANG Kai(Center for Geophysical Survey,China Geological Survey,Langfang 065000,China;Technology Innovation Center for Earth Near Surface Detection,China Geological Survey,Langfang 065000,China;Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang 065000,China;National Center for Geological Exploration Technology,Langfang 065000,China;School of Geophysics and Information Technology,China University of Geosciences(Beijing),Beijing 100083,China)
出处
《煤田地质与勘探》
EI
CAS
CSCD
北大核心
2023年第12期106-115,共10页
Coal Geology & Exploration
基金
国家重点研发计划课题(2018YFF01013500)
中国地质调查局地质调查项目(DD20230388,DD20189133,DD20190556)。
关键词
雄安新区及外围
深地震反射
地壳
精细结构
构造特征
Xiong’an New Area and its periphery
deep seismic reflection
crust
fine-scale structure
tectonic feature
