Early Cretaceous subduction initiation beneath southern Tibet caused the
northward flight of India
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Abstract
Collision between the Indian and Eurasian plates formed the ~2500 km long Yarlung Zangbo Suture Zone and
produced the Himalaya mountains and Tibetan plateau. Here we offer a new explanation for tectonic events
leading to this collision: that the northward flight of India was caused by an Early Cretaceous episode of subduction
initiation on the southern margin of Tibet. Compiled data for ophiolites along the Yarlung Zangbo Suture
Zone show restricted ages between 120 Ma and 130 Ma, and their supra-subduction zone affinities are best
explained by seafloor spreading in what became the forearc of a north-dipping subduction zone on the southern
margin of Tibet. The subsequent evolution of this new subduction zone is revealed by integrating data for arcrelated
igneous rocks of the Lhasa terrane and Xigaze forearc basin deposits. Strong slab pull from this new
subduction zone triggered the rifting of India from East Gondwana in Early Cretaceous time and pulled it
northward to collide with Tibet in Early Paleogene time.
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