Understanding the Deformation Structures and Tectonics of the Active Orogenic Fold-Thrust Belt: Insights from the Outer Indo-Burman Ranges

Abstract The tectonic deformation of the outer Indo-Burman Ranges (i.e., Chittagong Tripura Fold Belt, CTFB) is associated with oblique convergence Indo-Burmese plates since latest Miocene. This article presents detailed field evidence structures and their kinematics in exposed Tertiary successions CTFB. We combine observations made this study published structural, geodetic, seismic data sets to present an overview active framework region its strain partitioning. To determine kinematic evolution, décollement depth, amount strain, we combined geologic mapping, structural analysis fifteen anticlines, fracture/lineament analysis, paleostress faults that define ∼100 km wide Structural analyses suggest subhorizontal plane approximately 10% east-west shortening (oriented ~65°) perpendicular axial ~155°) CTFB anticlines. No significant transpression or strike-slip faulting has been observed and, therefore, suggests full slip-partitioning normal belt parallel inner IBR. Paleostress results are good agreement present-day stress regime, implies past dynamically related component India-Burma vector velocity motion.