关键词: 全新世走滑活动断裂, 拉分盆地, 地震遗迹, 复发间隔, 昔格达断裂

Abstract:

The paper studied the Late Quaternary activity of the Xigeda fault carefully based on the geomorphologic analysis of the landsat ETM data combined with field tectonogeomorphic observations and measurement. Results reveal that shape of the rivers and ridges along the fault showed the “S” or anti“Z”, or more “S”shape, which are end to end connected with each other, and an echelon oblique columns; the faulting way is sinistral strike slip with left step, and a series of pullapart basins and fracture lakes (lake distributed popularly)developed; that as Holocene active strikeslip fault, its latest active time was later than (1283±109) ka, generally, which is west dipping, with smaller (trend) strikeslip component and slip rates of 170 mm/a since late Pleistocene; that according to the seismic remnant and active characteristics of the fault, recrudescing interval of the fault activity is 10-12 ka or shorter.

Key words: Holocene strikeslip active fault, pullapart basin, seismic remnant, recrudescing interval, Xigeda fault