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South China was formed through the amalgamation of the Yangtze Block with the Cathaysia Block, but the timing of this amalgamation is controversial, ranging from Mesoproterozoic to Mesozoic. We report here SHRIMP U–Pb zircon ages, geochemistry and Nd–Hf isotopes of the Shuangxiwu Group volcanic rocks from the southeastern Yangtze Block. These rocks were strongly deformed, metamorphosed to greenschist-facies, intruded by 849±7Ma dolerites, and unconformably overlain by Neoproterozoic rift successions of no older than ca. 820Ma. The Beiwu and Zhangcun volcanic rocks from the middle and uppermost Shuangxiwu Group were dated at 926±15Ma and 891±12Ma, respectively. All the studied rocks are characterized by highly positive ɛNd(T) (5.4–8.7) and ɛHf(T) (11.0–15.3) values. The Pingshui basaltic and andesitic rocks from the lower Shuangxiwu Group, which were previously dated at ca …