Locating Lhasa terrane in the Rodinia and Gondwana supercontinents: A key piece of the reconstruction puzzle

Abstract

Abstract The debate over global continental reorganization from Rodinia to Gondwana likely stems from some key Neoproterozoic units being overlooked in previous reconstructions. Here we provide a self-consistent set of evidence, based on magmatism and metamorphism, that the Lhasa terrane is the “lost” part of NW India and retains crucial archives, including 760–730 Ma ophiolitic-arc magmatic rocks and evidence of a distinctive metamorphic event at ca. 660 Ma. Hence, the Lhasa terrane together with Madagascar and Seychelles formed in a late Neoproterozoic juvenile arc system laying either along the periphery of rifting Rodinia or outboard of the supercontinent. Subsequently, these terranes made up the northern East African Orogen (EAO) during the initial assembly of Gondwana. As a result of lateral-escape tectonics after collision and dextral strike-slip along the northern margin of Gondwana, the Lhasa terrane escaped from the EAO and had migrated to the northern margin of Australia by the Middle Cambrian.