Mixed crystalline basement of Junggar basin revealed by wide-angle seismic evidence

A wide-angle seismic reflection / refraction survey along a ~ 600 km long transect through the Junggar basin from Emin to Qitai allows to receive several images near N-S trending blind faults, which are located at the lower part of the upper crust, the middle crust and the lower crust within the basin and cut up the Moho. These faults, with high seismic velocity and without obvious dislocation, are considered as “extensional faults” formed by north-south compression and east-west extension. These deeply rooted faults provide channels via which basic to ultra-basic materials from upper mantle migrate into the crust and mix up with the crustal material causing thin thickness, high seismic velocity, high density and high magnetic intensity after cooling in the crust of the basin.