GEOPHYSICAL RESPONSE OF THE STRATIGRAPHIC DIVISION OF YIXIAN FORMATION IN XIUSHUI BASIN, NORTHERN LIAONING PROVINCE

By multiple technical means of surface geological survey, drill core logging, geophysical well logging and 2D seismic survey, with combination of lithostratigraphy, logging curve, 2D seismic and drilling data calibration, the Yixian Formation represented by LFD1 well and X-D1 well is divided into four lithologic members:the first member (K₁y¹) of basic volcanic rocks, the second member (K₁y²) of volcanic rocks with sedimentary-pyroclastic rocks, the third member of(K₁y³) of sedimentary rocks, and the fourth member (K₁y⁴) of acid volcanic rocks. The four members and interfaces have distinguished characteristics in outcrop, drill core, logging curve and seismic data. Both the comprehensive interpretation inference of gravity-magnetic-electric joint inversion and seismic reflection characteristics after well seismic calibration show that the four lithologic members of Yixian Formation, Lower Cretaceous, have certain spatial distribution characteristics and regularities.