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鄂豫皖毗邻区属中强地震区,主要构造为东大别断块。其边界断裂(郯城—庐江断裂带和麻城—团风断裂带等)控制了块内英山—霍山北东向对角线多闭锁点右旋剪切破裂带的强震活动,它是研究区的主要强震构造带。根据地壳形变测量,东大别断块相对东西两大断块均呈右旋,这与中国东部晚新生代地壳扭动的方式一致。然而郯城—庐江断裂带中南段里剪压性,麻城—团风断裂为剪张性。其构造力学性质的差异,很可能是由于前者为二级断块的边界构造;而后者是该二级断块内的三级断块的边界断裂。此二级断块内的深部上地幔隆起导致了麻城—团风断裂带的剪切扩张运动。1913年以来麻城、商城地区的强震活动或许与此有关;而霍山地区的较强地震活动,则与英山、罗田上地幔凹陷北缘莫氏面急剧变化有联系。此外,1917年霍山 6~(1/4)级地震和1932年麻城6级地震的孕震构造系统的分析表明:断块内次级闭锁断裂发震和受主干断裂控制的次级断裂发震,是我国板块内部现代强震的一种普遍构造模型。
The adjoining area of Hubei, Henan and Anhui is a moderate-strong earthquake area, with the main structure being the Dabie block. The boundary faults (Tancheng-Lujiang fault zone and Macheng-Tuanfeng fault zone) control the strong earthquakes in the right-lateral shear-fault zone of the north-east diagonal multi-closure in the block, which is the study area The main strong earthquake zone. According to the crustal deformation measurement, the Dadugan fault block has a right-lateral rotation relative to the east and west faults, which is consistent with the twist of the Late Cenozoic crust in eastern China. However, in the middle part of Tancheng-Lujiang fault zone, shear stress was cut and Macheng-Tuanfeng fault was shear tension. The difference in structural mechanics properties is probably due to the fact that the former is the boundary structure of the second-level fault block, while the latter is the boundary fault of the third-level fault block in the second-level fault block. The uplift of the upper mantle in this second-stage fault led to the shear expansion of the Macheng-Tuanfeng fault zone. The strong earthquakes in Macheng and Shangcheng area since 1913 may be related to this. The strong seismic activity in Huoshan area is related to the drastic change of Mohsurface in the northern margin of the upper mantle depression in the Yingshan and Luotian. In addition, the seismogenic tectonism of Huoshan 6 ~ (¼) earthquake in 1917 and Macheng Ms6 earthquake in 1932 shows that the occurrence of secondary blockage seismogenic fault in the fault block and the sub-fault seismogenic fault controlled by main fault , Is a universal structural model of modern strong earthquakes in our country.