2013年3月底至4月初青海省德令哈郊区连续发生了数次ML4.5左右的地震,市区震感强烈。利用双差定位法对该震群进行重新定位,发现震群空间分布呈近NS向,深度集中于4~10km的地表浅层,纵向深度剖面呈＂斗状＂断层特征;利用CAP（Cut and Past...2013年3月底至4月初青海省德令哈郊区连续发生了数次ML4.5左右的地震,市区震感强烈。利用双差定位法对该震群进行重新定位,发现震群空间分布呈近NS向,深度集中于4~10km的地表浅层,纵向深度剖面呈＂斗状＂断层特征;利用CAP（Cut and Paste）方法反演了震群中ML≥3.3地震的震源机制解,结果为走滑类型,震群特征与附近的主构造宗务隆山断裂带性质不符。地质勘探发现凹陷或盆地边缘主构造附近通常存在横向伴生断裂,这些断裂规模不大,以走滑性质为主。本次震群位于柴达木盆地北边缘,通过相似构造的对比,认为该区附近同样满足横向断裂存在的条件。由于本次震群各项特征与横向断层的构造理论十分相符,推断出该震群应该是这种微小断裂活动的结果,横向断裂通常规模不大,因此可判断出震群震源区未来发生强震的可能性较小。展开更多
Through comprehensive research on the various geophysical and geological data acquired recently, we consider that the Chasang area in the western uplift of Qiangtang is a huge south-dipping block which is overlapped b...Through comprehensive research on the various geophysical and geological data acquired recently, we consider that the Chasang area in the western uplift of Qiangtang is a huge south-dipping block which is overlapped by several east-west trending blocks rather than a simple and palaeo-doming existing for a long time. The structural and geophysical features of the area, which only alone limited between Shuanghu and Rongma districts, are of no regional significance. Their development is closely related with the approximately south-north trending transform faults developed during the Mesozoic era on the east and west sides of the area and their later continuous movement. The compressing, overlapping and uplifting of the Chasang area began at the stage of reversing of the Qiangtang Basin during the Lower Cretaceous, which is in direct relation with Bangonghu-Dingqing limited ocean's closure and the convergence of the neighboring blocks. The compression and overlapping of the area have further developed and reformed展开更多
文摘2013年3月底至4月初青海省德令哈郊区连续发生了数次ML4.5左右的地震,市区震感强烈。利用双差定位法对该震群进行重新定位,发现震群空间分布呈近NS向,深度集中于4~10km的地表浅层,纵向深度剖面呈＂斗状＂断层特征;利用CAP（Cut and Paste）方法反演了震群中ML≥3.3地震的震源机制解,结果为走滑类型,震群特征与附近的主构造宗务隆山断裂带性质不符。地质勘探发现凹陷或盆地边缘主构造附近通常存在横向伴生断裂,这些断裂规模不大,以走滑性质为主。本次震群位于柴达木盆地北边缘,通过相似构造的对比,认为该区附近同样满足横向断裂存在的条件。由于本次震群各项特征与横向断层的构造理论十分相符,推断出该震群应该是这种微小断裂活动的结果,横向断裂通常规模不大,因此可判断出震群震源区未来发生强震的可能性较小。
文摘Through comprehensive research on the various geophysical and geological data acquired recently, we consider that the Chasang area in the western uplift of Qiangtang is a huge south-dipping block which is overlapped by several east-west trending blocks rather than a simple and palaeo-doming existing for a long time. The structural and geophysical features of the area, which only alone limited between Shuanghu and Rongma districts, are of no regional significance. Their development is closely related with the approximately south-north trending transform faults developed during the Mesozoic era on the east and west sides of the area and their later continuous movement. The compressing, overlapping and uplifting of the Chasang area began at the stage of reversing of the Qiangtang Basin during the Lower Cretaceous, which is in direct relation with Bangonghu-Dingqing limited ocean's closure and the convergence of the neighboring blocks. The compression and overlapping of the area have further developed and reformed
