Neotectonism and reactivation of tectonic elements in eastern part of Shillong Plateau, India: constraints from morpho-tectonic analyses

Abstract

ABSTRACT The Shillong Plateau is the only elevated topography in the Himalayan foreland bounded and crisscrossed by several prominent faults and shear zones. The plateau is situated in a complex tectonic compressional set up, owing to which the fault systems both at the periphery and within tend to be neotectonically active. Due to the elevation difference of the plateau with the Brahmaputra and Meghna River valleys flanking it, coupled with the impervious lithologies present, an intricate network of drainage system has developed in the plateau. In this paper, morphometric and structural analyses of four selected drainage basins from the east-central part of Shillong Plateau have been carried out to comprehend the effects of neotectonic reactivation of fault systems and associated basin tilting which in turn controls the development of drainage pattern. This has led to the understanding of the effects of the ever-evolving fluvial landforms on the anthroposphere in this part of Indian sub-continent, where the agrarian-economy is completely dependent on the intricate fluvial systems.