关键词: 碗窑沟断层, 电阻率成像, 探槽, 乌鲁木齐

Abstract: The Wanyaogou Fault dislocates the Jurassic sandstone.The tilted bedrock becomes a natural barrier to the groundwater,and a water-rich stratum formed in the footwall which caused obvious resistance difference between the two walls of the fault.The electrical imaging is an effective way to detect the fault on this condition.The experimental electrical resistivity tomography survey was conducted to detect the Wanyaogao Fault.The results of 2-D resistivity inversion indicate that the electrical structures on both sides of the fault present obvious difference,the resistivity of the hanging wall is high,while that of the foot wall is low.And the interface of the high and low resistance regions inclines to the low resistance region.The electrical resistivity tomography survey was also conducted to detect other faults in Urmuqi which have similar tectonic characteristics with Wanyaogou Fault.And the electrical structures appear the similar abnormality.So the abnormal characteristic is an important indicator and basis for identification of fault in the Urumqi region.The faults in Urmuqi are almost all high-obliquity reverse faults.After comparing the electrical imaging with the trench section,we find the fault is not coincident with the borderline between the high and low resistance,but lies in the high resistance region.The fault inclination is reverse to the gradient direction of isolines.The fault location is near to the inflexion of the upper isolines.

Key words: Wanyaogou Fault, electrical imaging, trench, Urmuqi