Strain Analysis in a Part of the Chamba Syncline using Deformed Quartz Pebbles in Chamba Region of Northwestern Himalaya

Abstract

Samples of deformed pebbles in the slates from the Manjir Formation were collected from normal and inverted limbs of the Chamba Syncline. The axial ratios and orientation on two dimensional sections were determined from deformed quartz pebbles. The finite strain was calculated using Rf/φ technique. The two dimensional data were combined to give three dimensional finite strain and type of strain experienced by the pebbles at each locality. Regional variation in the strain distribution is represented by finite distortional strain (ε_s) for both normal and inverted limbs of the syncline. The results show that the deformation is of flattening type and the amount of strain increases from inner arc to outer arc of the Chamba Syncline. A total of about 28 per cent shortening has been noticed in the Manjir Formation.