THE APPLICATION OF GROUND PENETRATING RADAR TECHNOLOGY IN GEOLOGICAL MAPPING OF SHALLOW COVERED ACTIVE TECTONICS REGION:A CASE STUDY OF 1:50000 MAPPING OF NEOTECTONIC ZONE AND ACTIVE TECTONIC ZONE IN QING TONGXIA AREA,NINGXIA
YIN Yan-guang;SHI Wei;GONG Wang-Bin;QIN Xiang;ZHAO Yi;School of Earth Science and Recources,China University of Geociences;Institute of Geomechanics,China Academy of Geological Sciences;
Ground Penetrating Radar( GPR) detectionisa widely-used detection method in geological survey owing to its advantages of high-resolution,accurate positioning,high speed,flexibility,convience,profile visualization,real-time image display and so on. GPR detection technology is applied to detect Quaternary system and blind faults in the mapping of 1:50000 shallow covered active tectonics zone of Qingtongxia,Ningxia. Detection results show that 40 MHz GPR can effectively detect the quaternary system structure within 30 m below the surface,and 3 sets of Quaternary strata can be clearly defined. Drilling results confirm that Holocene Lingwu formation( Ql) from bottom to top is comprised of mudstone,gravel layer,and sand or mud with gravel. The radar image reveals that the south of the Liumugao fault of main fault has structural features of upward divergence and downward convergence with flower structure,which is consistent with the results of trench investigation. It shows that GPR can accurately demarcate the plane position and vertical detail structure of blind faults. This work indicates that GPR technology is feasible,effective and convenient for blind fault investigation and sequence division of the upper part of the Quaternary in shallow covered active tectonic zone.