HR: 0800h
AN: GP41B-0876    [Abstracts]
TI: Study Hukou fault by using DC resistivity and CSAMT methods
AU: * Yi, Y C
EM: user15@cyu.edu.tw
AF: Chun-Yi, Yu, user15@cyu.edu.tw, Jung-Li, 320 Taiwan
AB: Geoelectric methods are widely used in the geophysical exploration. They did well in groundwater prospecting, mapping the changes of depositional environment, fault identification, and mineral detection etc. Two common electrical methods used in the field are the direct current resistivity (DC resistivity) method, and the controlled source audio-magnetic telluric (CSAMT) method. A successful survey depends on the features of the surveyed targets, man-made noise, and topography. The purpose of this study is using DC and CSAMT methods to investigate the Hu-kou fault in the northwestern of Taiwan. The Ho-kou fault is a thrust fault, extending from the Ping-Jen to the south of Ho-kou with a length of 23 km. The strike is in the north-northeastern direction. Ku(1963) differentiates the fault with a vertical displacement of 30 m by photogeologic study. A total of 40 vertical electric sounding (VES) locations and 5 CSAMT lines were deployed in the study area, the surveyed results are as following­G 1. The VES results provide shallower layer information. The resistivity of the layers from the surface to a depth of 50 m ranges from 10 to 600 ohm-m. The geoelctrical layer is K-type. The resistivity of the southern part of the Ho-kou fault is generally higher than that of the northern part. 2. The CSAMT results indicate that the resistivity of the layers is increased with depth. The highest resistivity among the layers is more than one thousand ohm-m. The resistivity of the layers in the southern part of Hu-kou fault is higher than the northern part at the depth 100 meters to 200 meter Combined the DC with the CSAMT results, it indicates that the position and features of the fault Hukou fault can be pointed out. In addition, the resistivity structures from the shallower to deeper layer are also be delineated.
UR: http://www.cyu.edu.tw
DE: 0903 Computational methods: potential fields (1214)
SC: Geomagnetism and Paleomagnetism [GP]
MN: Fall Meeting 2005