Quantitative provenance analysis for the Proterozoic sedimentary basin in the Yangtze Block: Implications for reconstruction its positions in Columbia and Rodinia supercontinents

The tectonic affinity and paleogeographic position of the Yangtze Block in the Proterozoic supercontinent cycle are essential in reconstructing these supercontinents but remain debated. This study presents new detrital zircon U-Pb-Hf isotopic analysis of the Fifth Member of the mid-Mesoproterozoic Tong’an Formation (TA-5) in the southwestern Yangtze Block. Integrating these results with published detrital zircon ages from the Proterozoic strata in the Yangtze Block, the inverse Monte-Carlo modeling with optimized forward modeling and non-metric multidimensional scaling (MDS) methods are employed to quantitatively constrain the provenance evolution of the strata from the late Paleoproterozoic to the early Neoproterozoic, thereby constraining the paleogeographic position of the Yangtze Block in different periods. Our results constrain the deposition of TA-5 to have initiated after ca. 1516 Ma and continued until at least ca. 1389 Ma. Monte Carlo mixing calculations reveal that its provenance were derived from the southwestern (48%) and northern (24%) Yangtze Block, the Gawler Craton of southern Australia (3%), the Transantarctic Mountains in East Antarctica (9%), and West Laurentia (16%). Extending this quantitative provenance analysis to other Proterozoic strata of the Yangtze Block enables us to reconstruct its paleogeographic evolution: during the late Paleoproterozoic to the early Mesoproterozoic, the Yangtze Block was adjacent to the northwestern Laurentia and southern Siberia; by the middle Mesoproterozoic, it bordered the Gawler Craton of southern Australia, the Transantarctic Mountains in East Antarctica, and West Laurentia; from the late Mesoproterozoic to the early Neoproterozoic, it maintained proximity to East Antarctica and southern Australia while drifting away from Laurentia. These findings elucidate the dynamic paleogeographic evolution of the Yangtze Block throughout the Proterozoic and underscore the potential of quantitative provenance analysis in reconstructing the Precambrian supercontinent.