The formation of the Sichuan Basin, South China, during the Late Ediacaran to Early Cambrian

The Upper Ediacaran to Lower Cambrian of the Sichuan Basin in South China has long been considered be dominated by shallow-water deposition. Hydrocarbon exploration, however, revealed that a NW-SE trending intraplatform trough formed basin during same period. Although different models have proposed, formation and evolution are still not fully understood. In this study, we investigate both origin integrating seismic interpretation, well correlation tectonic subsidence analysis. data clearly show three stages development trough. first stage, early Late Ediacaran, is characterized considerable thinning lower two members from platform margins second late backstepped extent expanded significantly width ca. ~400 km. third Early Cambrian, was gradual filling onlapping margins. Backstripped curves one, or closely spaced episodes linear starting at ~550 Ma then decreasing exponentially until ~450 Ma. shape consistent with low, slow amounts lithospheric stretching thickened cratonic lithosphere. increases centre NW basin. Interestingly do correlate contoured values increased infer palaeogeographic embayment large carbonate developed broad, ramp-like area low tilting down proto-Tethyan ocean located