Abstract: Using Q value tomography and hypocenter distribution image, the 3D Qvalue structure and the seism starting time image are obtained in midupper crust in Jiashi seismic area. The results show on the horizontal sections at the different depth, every Q value image exists low Q value zones, main orentation is EW striking, NNE striking and NNW striking, which are respectively corresponding with Keping fault, Yangdaman fault and Maigaiti fault in the study region. It is supposed that the low Q value zones are probably deep faults in study area. On the other hand, on the vertical profiles, large area of low Q value zones exist along belt of 77°E and Q value structure of two sides of this belt are obviously different. Seism starting time plane image displays that dominate orientation is NNW and NE, which intersects with the after shock concentration area. These features are the active structural setting of this area. And it provides deep tectonic information for the geologic structure research and the petroleum resources exploration.

Key words: 3D, Qvalue tomography, deep crust, fault, Jiashi of Xinjiang