关键词: 玛纳斯地震, 盲断裂, 褶皱地震

Abstract: The 1906 Manas earthquake is an important event in the northern Tianshan of China. TheSeismogenic fault controlling this earthquake has not been well understood. Detailed field investi-gation indicates that the ground ruptures in the epicentral area were caused by gravitational andshaking effects during the earthquake. The fresh fault scarps along the Tugulu-Manas-Houer-goush reverse fault and fold zone are the possible surface ruptures associated with the 1906 Manasearthquake. The displacement is between 0.2 and 0.5m. Total length of the fault scarp is lessthan 10 km which is far more less than a normal rupture length associated with an earthquake of magnitude 7.7.Anticlinal uplifting along this reverse fault and fold zone indicates that the earthquake probably occurred along low-angle reverse fault at depth as a blind reverse faulting event.The surface rupture and deformation took place far away from the epicentral area. Most of thecoseismic deformation was accomodated by folding and uplifting,and only less than 10 km surface rupture was formed.Thus,the 1906 Manas earthquake is probably a“folding earthquake”.

Key words: Manas earthquake, Blind thrust, Folding earthquake