2-D seismic data interpretation combined with structural analysis was used to build a geometry model and determine active ages of the Gudongshan fault belt.The formation and evolution of this fault belt with complicated tectonic deformation may be closely related to the evolution of oceanic basins and orogenic belts around Tarim Basin.Faulting activities were the most obvious in key tectonic periods of Tarim Basin

namely the Middle Caledonian

Early Hercynian

Middle Hercynian

Early Himalayan and Later Himalayan.Faults No.1 and No.2 in the Gudongshan fault belt control the thickness of the Palaeozoic strata on both sides of the belt and also show signs of multiple-stage activities.Fault No.1 was active during phase Ⅰ and Ⅲ of the Middle Caledonian and shows feature of progress intensification of its activity.Fault No.2 was developed in the Early Hercynian and successively experienced negative inversion in the Carboniferous and positive inversion at the end of Paleogene.Fault No.3 was formed in the Early Himalayan and controlled the tectonic framework of the Precambrian basement which is higher in southwest and lower in northeast.Faults No.4 and No.5 were developed in the Later Himalayan.The former has a thrust displacement up to 20 km and a denudation-caused monocline at the hanging wall.