A Study of Fault Site at Byeonggok-myeon, Yeongdeok-gun, South Korea

영덕군 병곡면의 단층 노두 특성에 대한 연구

In the southeastern part of the Korean Peninsula, the Yangsan Fault, an active fault zone, has developed. Many earthquakes occur around these faults, and the possibility of earthquakes occurring along the branch faults is being discussed. On the other hand, the Yeongdeok Fault is reported in Yeongdeok-gun, which is the northern part of the Yangsan fault. In this study, goemorphic characteristics of a set faults found on the outcrop of the gentle slope of the coast of Byeonggok-myeon were analyzed and granulometric and geochemical characteristics of sediments and other materials, including fault gouges were analyzed. The outcrop of Byeonggok-myeon is the part of the fault core and can be divided into two parts. Theses fault are formed on the upper part of the Mesozoic bedrock and the tertiary sedimentary layer of red sand-supported clasts are covered in several sedimentary units. The faults were normal fault sets, and a number of vertical cracks were developed, and glossy surfaces were observed in the fault area. It appears that these faults have occurred after alluvial deposition had been formed. In the case of samples from fault gouges, there were differences in particle size and geochemical characteristics from the surrounding area.