Abstract:The temporal-spatial distribution characteristics of fault structures on the northwestern margin of Xining basin were investigated by using the audio-magnetotelluric method and 2D seismic exploration,with the purpose of providing the hydrogeological borehole properly so as to carry out the comprehensive investigation and evaluation of hydrogeology,environmental geology and engineering geology in eastern cities of Qinghai Province,find out the stratigraphic structures and geological structures,and study geophysical characteristic parameters in the key region.The results show clearly that there exists Xiamen thrusting-nappe fault on the northwestern margin of Xining basin,which dips NW,with dip angle about 65 °.The other two fractures were found in the river valley,away from mountains,and both are presumably associated with Nanmenxia strike-slip fault.In addition,the response characteristics of stratigraphic lithology,apparent resistivity and the velocity of seismic reflection wave were summarized.The hydrogeological borehole was drilled to verify the existence of Xiamen thrusting-nappe fault.The drilling coring is quite consistent with the results from the geophysical exploration methods.Several fault fracture zones exist in this borehole penetrating the Neo-Proterozoic crystalline limestone.
龙慧, 孙晟, 刘义, 郭淑君. 西宁盆地北西缘南门峡—台子地区断裂构造地球物理探测[J]. 物探与化探, 2018, 42(2): 241-246.
LONG Hui, SUN Sheng, LIU Yi, GUO Shu-Jun. Surveying fault structures by geophysical exploration technique on the northwestern margin of Xining basin. Geophysical and Geochemical Exploration, 2018, 42(2): 241-246.