Isolated Crustal Partial Melting in the Southern Tibetan Plateau From H‐κ‐c Method

Abstract

The crustal thickness and average Vp/Vs ratio are basic parameters to understand the current state and the tectonic processes in the Tibetan Plateau (TP). We gather receiver functions in the central‐southern TP and extract spatial variation of crustal thickness and Vp/Vs ratio using the H‐κ‐c method with careful quality control and stability analysis. Our results highlight the regions with high Vp/Vs ratios in the central‐southern Qiangtang block and two isolated patches around the Yarlung‐Zangbo suture, suggesting crustal partial melting. The disconnected high‐Vp/Vs patches imply a restrained pattern for present‐day crustal flow in the southern TP. Further correlation with mantle observations suggests that the high Vp/Vs region in the north can be attributed to mantle upwelling after lithospheric delamination, and the two isolated patches in the south may be related to the tearing of the Indian mantle lithosphere.