Provenance of the early Paleozoic sedimentary succession in the Lancang Block, SW China: Implications for the tectonic evolution of the northern margin of Gondwana

•Sediments of the late Ordovician Lancang Group in the Lancang Block, SW China, were sourced mainly from the northern margin of Gondwana.•Provenance change of the sediments might reflect initial subduction of the Proto-Tethys in the Ordovician.•The Lancang Block had affinity to Gondwana during the early Paleozoic.