Ediacaran carbon cycling and Shuram excursion recorded in the Tarim Block, northwestern China

•A mixed siliciclastic-carbonate shelf was evolved to a carbonate shelf in the Tarim Block during the late Ediacaran.•Complete δ13C profiles demonstrate two negative and two positive anomalies in the upper Ediacaran of Tarim Block.•The largest negative δ13C anomaly in the upper Sugetbrak Formation could be correlated to the Shuram excursion.•All δ13C anomalies are globally correlative.•The Shuram excursion was probably related to the storm-enhanced oxidation of the DOC reservoir.