Linking the Kangra piggy–back Basin with reactivation of the Jawalamukhi Thrust and erosion of Dhauladhar Range, Northwest Himalaya

Abstract

A dynamic coupling between climate-induced erosion and tectonics is envisaged for the growth of the Himalaya. The Dhauladhar Range (NW Himalaya), between the Beas and Ravi rivers, shows large altitude variation along the regional trend from southeast to northwest. The altitude rises between 5000 m and 4000 m in the eastern part and decreases between <4000 m and 2800 m in the western part. Eastern part of the Range is characterized with focused and highest precipitation, concentration of microseismicity and the formation of Kangra Basin to its south; whereas all these features are lacking in the western part. The Kangra Basin is a post-Siwalik intermontane basin between the Dhauladhar Range in the north and the Siwalik Range in the south. The basin-fill is essentially derived from the southern flank of the Dhauladhar Range as a consequence of erosion due to deglaciation. The Kangra Basin is developed as a piggy-back basin over the hanging wall of the foreland propagating Jawalamukhi Thrust (JT). The Optically Stimulated Luminescence (OSL) dating of fluvial strath terrace surfaces, across the hanging wall, indicate late Quaternary reactivation of the JT. The Kangra Basin sediments yield late Quaternary OSL ages similar to that of the strath terraces. This suggests that formation of the Kangra Basin is synchronous with reactivation of the JT, implying a linkage among formation of the Kangra Basin, its filling through erosion of the Dhauladhar Range and reactivation of the Jawalamukhi Thrust.