Uplift Mechanism of the Highest Mountains at Eastern Himalayan Syntaxis Revealed by In Situ Dense Gravimetry
Yawen She, Guangyu Fu
Abstract
Abstract Dense gravity surveys at 408 stations are built around eastern Himalayan syntaxis (EHS). Free‐air gravity anomalies (FGAs) and Bouguer gravity anomalies (BGAs) are obtained based on the in situ data, while the modeled and observed FGAs are merged to increase the accuracy of the gravity anomalies. The variation ranges of FGAs and BGAs are −350–100 and −520 to −320 mGal, respectively. The density structures inversed by the BGAs represent a low‐density zone below the Namche Barwa‐Gyala Peri metamorphic massif. The Moho below the metamorphic massif is significantly shallower than the surrounding areas, and the variation range is between 45 and 75 km. A gravity admittance method is used to study the uplift mechanism of the highest mountains at the EHS. Our result shows that rapid uplift is primarily attributed to the upwelling of the mantle.