Triassic detrital records in the western Dian-Qiong suture, South China: Implications for the eastern Paleo-Tethys evolution

The provenance and tectonic setting of the Middle Triassic siliciclastic rocks from the Malipo basin, western Dian-Qiong suture, South China have been examined using the detrital mode, geochemistry and detrital zircon U-Pb dating. The petrological and geochemical results indicate increasing degrees of weathering, sorting and sediment recycling from north to south. Given the detrital zircon ages, we suggest that the sediments within the northern and southern Malipo basin have multiple provenances and distinctive tectonic settings, including (1) the former was deposited in a fore-arc setting with derivation from mixed Late Permian-Middle Triassic volcanic arc and uplifted Palaeozoic sequences and (2) the latter deposited in the passive margin of the Northern Vietnam terrane with the predominate derivation from recycled Early Palaeozoic orogen and uplifted Palaeozoic and Precambrian successions. These sediments should be tectonically juxtaposed during the Late Triassic due to the closure of the Paleo-Tethys branch ocean and the continued South China-Indochina collision.