Subduction transference drove the Mesozoic convergence of microcontinents from Gondwana to Asia

Abstract

How microcontinents successively migrated from Gondwana to Eurasia is paramount in understanding the Mesozoic evolution of the Tethys Ocean. The rifting and collision events and their potential spatio-temporal relationship may play a key role in this evolution. We compiled available Permian-Jurassic paleomagnetic data from the Lhasa terrane, revealing that it drifted away from Gondwana ~210 million years ago, which is ~10 million years earlier than the South-North Qiangtang collision. Similarly, the Lhasa-Qiangtang collision preceded the rifting of India by ~10 million years. These age gaps of similar kinematic circuits align well with the time required for collision-induced subduction transference, whereby a new subduction zone forms outboard of the newly accreted terrane. Then, the slab-pull force can be transmitted to the southern segment of the younger Tethys slab by coupling across the oceanic ridge/transform system, such that subduction transference drives the in-sequence one-way convergence of microcontinents with Eurasia. (Figure presented.)