Thesis (M.Sc.)--Chulalongkorn University, 2013

The objectives of this research are to quantify the finite strain of rocks and describe the deformation history of rocks in area of Lansang Waterfall, Tak Thailand where located within the Mae Ping shear zone; an affected area of past India- Asia penetration. By this process the structural geology on this area was accumulated strain inside and responded it in form of deformation. This research quantified the finite strain of rocks on this affected area from deformed minerals and a quantity of finite strain can be described by strain ellipsoid of rock followed by Fry’s method (Fry, 1979). From the strain quantitative analysis of rocks from deformed minerals in area of Lansang Waterfall, Tak Thailand follwed by Fry’s method (Fry, 1979) found that from all 13 rock sample locations, the averaged finite strain ratio of rocks and the angle- value between the longest axes of strain ellipsoid and the deformation boundary ranged between 1.35 to 1.69 and 22°to 41°, respectively. The shape of strain ellipsoid and the relative between that value intense the deformation process that applied and lead structural geology accumulated strain inside and finally deformed which the process of left- lateral simple shear applied on this area on the direction of NW- SE and lead deformation occurred on of Lansang Waterfall, Tak Thailand during the Eocene. Moreover, when compared the result of this research with the further work found that they are corroborated and related to each other.