Unraveling the character and source of late Mesoproterozoic-early Neoproterozoic sedimentary sequences is crucial in constraining Rodinia reconstructions. We carried out an integrated geochemical, zircon U-Pb geochronological and Lu-Hf isotopic study of the Shilu Group and the overlying Shihuiding Formation in Hainan, South China. These two successions are chemically mature and dominated by siliceous components. The Shilu Group was mainly derived from felsic arc lithologies whereas the Shihuiding Formation was from recycled sedimentary materials and records a transition from convergent to passive margin settings during the late Mesoproterozoic-early Neoproterozoic in Hainan. Detrital zircons from the Shilu Group and Shihuiding Formation yield similar age populations, with maximum depositional ages of ~1,100–1,000 Ma and ~900 Ma, respectively. The Shilu Group matches well with the Kunyang Group outcropped in the Yangtze Block in depositional age, detrital zircon age populations and Lu-Hf isotopic compositions, and geochemical characteristics, whereas the Shihuiding Formation exhibits significantly different detrital age populations from the Wanquan Group in the Cathaysia Block. This indicates that Hainan was linked to the Yangtze Block rather than the Cathaysia Block in the late Mesoproterozoic-early Neoproterozoic. The Shilu and Kunyang groups have similar detrital age patterns to the late Mesoproterozoic to early Neoproterozoic strata in northwest India and are distinct from their equivalents in west Laurentia, suggesting an external location of Hainan-Yangtze in Rodinia.
- detrital zircon dating
- hafnium isotopic compositions
- Shihuiding Formation
- Shilu Group
- west Hainan