吐鲁番盆地地震地质初步研究

吐鲁番盆地是海西期褶皱基底上发生、发展起来的沉积盆地．晚新生代以来，盆地演化为单侧冲断推覆型压性盆地。盆地本世纪内地震活动水平整体上是较低的，但区内断裂、褶皱活动自晚更新世晚期以来就一直进行着。盆地中央断裂带经开挖研究认为，全新世以来有３次古地震活动事件，其大震复现间隔为３０００年左右．由于最后一次大震发生距今已有约２５００年，所以盆地中央潜在大震的危险。

A PRELIMINARY INVESTIGATION ON SEISMO-GEOLOGY IN TURPAN BASIN

Turpan basin, the depositional basin, has been appeared and developed from the Hercynian fold basement. It has been evoluted to unilateral thrustnappe compressive basin since Late Cenozoic era. Although seismicities in the basin since this century generally are gentle and weak,the faults and folds in the area are kept activating since Late Pleistocene. Through ditch-investigation, we got to know that the centre fault zone within the basin has undergone paleoearthquake events three times since Holocene. It is estimated that the large shock recurrence interval might be about 3000 years,while the latest one has passed about 2500 years before present. Therefore,we take the basin as the one that has potential dangers of large earthquake occurrence.