The
Gangdese batholith or
Gangdese volcanic arc is a major geological structure in the south of the
Lhasa terrane in Tibet, to the north of the
Himalayas. The
batholith formed around 100 million years ago, and was volcanically active for about 20 million years. It reactivated around 65 million years ago as the Indian plate approached Eurasia, and was active for another 20 million years.