对武清-北京-赤城剖面段的人工地震测深资料,利用常规地震测深方法进行处理与计算,目的是查明该地区二维地壳速度结构和构造的基本特征、断层的空间展布特征和深浅部地质构造环境等.结果表明,不同区域的地壳速度结构在纵向和横向上均具有明显的非均匀性.地壳呈层状结构,地壳厚度由武清的31.0km向北西至延庆逐渐加厚为40.0km.在北京下方壳内界面起伏较大,莫霍面在北京的北西方向有一急剧加深,在约加km范围内M面起伏变化达5.0km.根据地震波动力学与运动学特征,以及二维地壳速度等值线和地震界面起伏变化等特征,沿剖面推测了5条地壳浅部断裂.
In this paper the crustal velocity structure is obtained along Wuqing - Beijing- Chicheng profile, using wide angle reflection and refraction data. The results reveal strong vertical and lateral heterogeneities in the crust. The crust has layered features and its thickness gradually increases from 31.0 km in Wuqing to 40.0 km in Yanqing. The strong variation of topography of the crustal interfaces appears around the Beijing area, and the Moho deepens rapidly in the northwestern direction of Beijing area. Five shallow faults in the crust are inferred along this profile, based on the crustal velocity structures and the variations of the crustal interfaces.