Eastward Dipping Style of the Underthrusting Indian Lithosphere Beneath the Tethyan Himalaya Illuminated by P and S Receiver Functions

To explore the west-east variations in underthrusting Indian lithosphere, we investigate lithospheric structure using P and S receiver functions obtained from a linear array of 19 broadband stations spanning Tethyan Himalaya at 85.5–88.5°E. Our observations Main Himalayan Thrust (MHT) Moho serving as top bottom boundaries depths 42–54 km 60–72 km, respectively, suggest that thinning lower crust with an eastward inclined geometry is beneath Himalaya. An intra-crustal low velocity zone (LVZ) immediately above MTH 32–42 imaged, likely resulting presence crustal dehydration partial melting. We propose this LVZ induces southward extrusion melt-weakened material itself channel facilitates development duplexing structures, by which materials could be accreted into wedge along north-south mid-crustal ramp MHT. The dipping lithosphere-asthenosphere boundary clearly observed ranging 90 to 126 generally coincides changing trends MHT Moho. These can attributed steepening subduction angle lithosphere.