Timing of rifting and drifting of the Cimmerian Continent: Insights from Permian to Triassic strata on the Tibetan Plateau

Accurately constraining the timing of rifting and drifting of the Cimmerian Continent is crucial for reconstructing the transition from the Paleo-Tethys to the Neo-Tethys Ocean. Sedimentary rocks provide critical evidence for these processes. In this study, we utilize the Zhongba micro-terrane, which remained situated along the northern Indian margin of Gondwana throughout the late Paleozoic, as a reference, and conduct a comprehensive comparison of its Permian to Triassic sedimentary rocks with those of the South Qiangtang terrane, representing the Cimmerian Continent. By integrating analyses of depositional environment, sedimentary provenance, and tectonic setting, we find that during the Asselian to Sakmarian both terranes were situated on the stable passive margin of Gondwana, sediment being predominantly derived from the northern Indian margin of Gondwana. However, from the Artinskian to the Middle Triassic, their evolution diverged significantly. The South Qiangtang terrane experienced a shift to a tectonically active setting, marked by an abrupt provenance change to syn-depositional magmatic sources, while the Zhongba micro-terrane maintained stable passive margin deposition, its provenance consistently linked to the northern Indian margin of Gondwana. These data, combined with previous paleontological and paleomagnetic data, provide strong evidence that rifting of the Cimmerian Continent initiated during the Artinskian to Kungurian, and transitioned to a drift phase away from the northern margin of Gondwana by the Middle Permian. Together, these findings offer robust sedimentological evidence for reconstructing the late Paleozoic oceanic-continental configuration of the Tethyan realm.