- 著者
-
谷山 尚
- 出版者
- 一般社団法人 日本活断層学会
- 雑誌
- 活断層研究 (ISSN:09181024)
- 巻号頁・発行日
- vol.2015, no.42, pp.35-53, 2015-03-31 (Released:2015-12-23)
- 参考文献数
- 29
A distinct element method analysis was carried out to examine the deformation of unconsolidated overburden subjected to a high dipping oblique normal basement fault displacement. About 4 million spherical particles were used to model the overburden overlying a basement fault which has a dip angle of 60 degrees. Effect of normal fault component and strike slip fault component on the deformation of the overburden was investigated. The deformation was affected by both normal fault and strike slip fault component of the basement fault. Very steep high strain zones developed in the middle and lower part of the overburden and while they were formed on the footwall side of the basement fault in the case of a large normal fault component, they were formed on the hanging wall side of the basement fault in the case of a large strike slip fault component. Near the surface, in the case of a large normal fault component, large deformation mainly due to the horizontal compression was observed on the hanging wall side and it was followed by high strain zones on the foot wall side caused mainly by the horizontal extension. En echelon high strain zones were observed on the hanging wall side of the basement fault in the case where a strike slip fault component was large mainly because of the strike slip fault movement and partly because of the horizontal compression caused by the normal fault movement of the basement fault. When a normal fault component and a strike slip fault component were of the same magnitude, high strain zones almost parallel to the basement fault developed on both sides of the basement fault trace and between them high strain zones striking obliquely to the basement fault trace were formed. The angle at which high strain zones in the overburden strike to the basement fault trace was very small in the case of a large normal fault component and the result showed the possibility of a right step pattern if normal fault displacement with a slight right lateral strike slip fault component was applied to the overburden.