Detrital zircons of the Devonian-Permian sandstones in the Qiangtang terrane, Tibet: Implication for Qiangtang rifting from Gondwana and uplift history of the Central Uplift

Abstract

• New zircon ages of Devonian-Triassic deposits reveal sedimentary provenance change. • The breakup of the Qiangtang terrane from Gondwana occurred at about 288 Ma. • Primitive uplift of the Central Uplift occurred during the late Permian. • Closure of the Paleo-Tethys Ocean resulted in the uplift of the Central Uplift. This article reports new zircon U-Pb ages of the Devonian-Permian sedimentary rocks exposed in the central Qiangtang to reveal the change of sedimentary provenances through time. The age spectra of the Devonian and Carboniferous strata in the Qiangtang terrane are generally similar. They are typically characterized by two primary age populations at 520–700 Ma and 900–1000 Ma, indicating a Gondwana affinity. The Qiangtang terrane was part of the Gondwana supercontinent during a long period from the Ordovician to early Permian. The breakup time of the Qiangtang terrane from Gondwana is at ∼288 Ma, which is characterized by a drastic provenance change. The sedimentary evolution, together with detrital zircon ages also provides important perspectives on the uplift process of the Central Uplift in the Qiangtang terrane. Our data reveal that a primitive uplift of the Central Uplift occurred at the Late Permian. Although a continuous uplift has developed during the Early-earlier Middle Triassic, the Central Uplift was still an underwater environment due to rapid sea level rise. The final closure of the Paleo-Tethys Ocean and its branch gave rise to the uplift of the Central Uplift at the late Middle-earlier Late Triassic.