【摘要】 首都圈地区是中国大陆东部构造极为复杂的地区之一。本文利用首都圈地区布格重力资料,采用小波多尺度分析方法对布格重力异常信息进行了局部场分离,对场源在横向及纵向上所产生的异常现象进行了多层次的分析,将这些现象与地质构造环境建立起联系,对其产生原因给予了地质上的充分解释。重点对小波变换细节图中存在的规模较大、特征较为明显的两条NE向及一条NWW向布格重力异常带进行了深入分析,对异常所揭示的构造现象在地壳不同深度的展布特性等进行了研究。研究发现,3条布格重力异常分别反映了华北地区的3条构造带,分别为太行山前构造带、沧县构造带以及张家口-渤海构造带,每个构造带分别由次级隆起、凹陷以及断裂构造单元组成。研究认为太行山山前断裂带为深大断裂,构成了华北裂谷盆地与太行山隆起的地球物理分界,沧县构造带与张家口-渤海构造带新生代以来仍具有一定的活动性。其中在两条NE向构造带与NNW向构造带的交汇区域,地壳结构最为复杂,形成了两条非常重要的地震带,在今后的工作中需要重点关注。通过研究,对首都圈地区构造体系及地壳结构有了深入认识,为进一步研究华北地区壳幔结构提供了参考。更多还原

【Abstract】 Tectonic setting of the capital area is extremely complex in east China.The study separated local Bouguer gravity anomaly information of the capital area using the method of wavelet multi-scale;analyzed and explained the sources of Bouguer gravity anomaly in terms of horizontal and vertical aspects;tried to establish the relations between these phenomena and geological structures;and finally explained their geological mechanism.With an emphasis on two large and distinct Bouguer gravity anomaly zones present in the figures plotted by wavelet multi-scale,we studied the distribution features of the structural phenomenon revealed by the anomalies.Research also indicates that three Bouguer gravity anomaly zones reflect the three structural zones in North China region,Taihang Mountain Tectonic Zone,Cangxian Tectonic Zone and Zhangjiakou-Bohai Tectonic Zone,each of which contains secondary uplifting,depression and faulting units.It is suggested by this study that foreland fault zone of Taihanshan Mts belongs to deep-seated faulting and constitutes the geophysical boundary between North China rifting basin and Taihanshan rising.Cangxian structural zone and Zhangjiakou—Bohai structural zone have been active since Cenozoic.Crustal structure is very complicated especially at the convergence of NE-trending and NNW-trending structural zones,forming two important seimic zones,on which our future exploration should focus.Our research has led a thorough understanding of the tectonic system and crustal structure in the capital area,and provides the guidance for further study on the mantle-crustal structure of North China.更多还原