关键词: 马边-永善地震带, 推覆构造, 盖层滑脱, 喜马拉雅构造域

Abstract: Many investigations have been made on a series of strong earthquakes that occurred in Mabian-Yongshan-Leipo, Daguan area successively. Basing on the characteristics of folds and faults and distribution of stress, we suggest that there exists a relative variation process, being from strong to weak, from west to east. It is inferred that the source of stress may be derived from a lateral pushing force and the resulting seismic zone forms a part of Mabian-Zhaotong-Qujing fault zone, being an eastern boundary of longitudinal tectonic zone in West Sichuan, and also being an earthquake-controlling basement fault zone along the boundary between geotectonic elements, Qinghai-Xizang plateau and Sichaun basin.

Key words: Mabian-Yongshan seismic zone, Imbricate structure, Overlying strata decollement, Himalayan tectonic domain