Linking a prolonged Neo‐Tethyan magmatic arc in <scp>S</scp>outh <scp>A</scp>sia: Zircon U‐Pb and Hf isotopic constraints from the Lohit Batholith, <scp>NE I</scp>ndia

Abstract

Abstract The Neo‐Tethyan subduction that operated before the I ndia‐ A sia collision resulted in an Andean‐type convergent margin in S outh A sia and was associated with extensive arc magmatism that formed the Transhimalayan batholiths. Magmatism in the Gangdese Batholith, the largest batholith exposed in the Lhasa terrane of southern T ibet, is considered to have lasted from the early Jurassic to Eocene. However, eastward correlation of the Gangdese Batholith is uncertain because it is truncated by the eastern H imalayan syntaxis. Here, we report new data from the Lohit Batholith, NE I ndia, including: (i) zircon U‐Pb ages of five granitoids from ca. 148 to 96 Ma; and (ii) zircon Hf isotopes of these rocks that yield high and positive ε Hf (T) values. We argue that the Lohit Batholith is the eastward extension of the Gangdese Batholith, and can be correlated southward to the Wuntho‐Popa arc in West Burma, thus linking a prolonged Neo‐Tethyan magmatic arc system from southern T ibet to S outheast A sia.