Geology and Three Dimensional Finite Strain Analysis around Annapurna Himal, Central Nepal

Contoured diagram of crenulation cleavage shows a small circle, axis of which indicates N45°E, E10°. Contoured diagram of minor fold shows also the same small circle as that of crenulation cleavage. Therefore, crenulation cleavage and minor fold were firstly formed in the area and then a flexural slip fold deformed the crenulation cleavage and minor fold. The axis of the flexural slip fold is the same as the axis of the small circle, that is, N45°E, E10°. The important point obtained by the 3D strain analysis is that the poles of XY plane of strain ellipsoid of 13 gneiss pieces sampled around the area show the same small circle, axis of which indicates N45°E, E10°. The reason why their small circles coincide with together is still an open problem for the future.