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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. ==Formation== The Lhasa terrane moved northward and collided with the Qiangtang terrane along the Bangong-Nujiang Suture towards the end of the late Jurassic (), and collision activity continued until the early Late Cretaceous () Ma. The collision caused a peripheral foreland basin to form in the north part of the Lhasa terrane, which persisted into the Early Cretaceous. In some parts of the foreland basin the north-dipping subduction of the Neotethyan oceanic crust below the Lhasa terrane caused volcanism. The Gangdese volcanic arc was formed as this subduction continued along the southern margin of the Lhasa terrane. The batholith intrudes the southern half of the Lhasa terrain. It is the largest Transhimalayan plutonic complex. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Gangdese batholith」の詳細全文を読む スポンサード リンク
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