Sedimentary distribution of evaporites in Wusongge'er Formation in central Tarim Basin and reconstruction of prototype basin

The Middle-Lower Cambrian Wusongge'er Formation in the Tarim Basin hosts extensive evaporite deposits, yet the formative processes of these evaporites under equatorial arid climates and their tectono-sedimentary implications remain poorly constrained. Previous studies, limited to low-resolution seismic data and outcrops in the northwestern margin, failed to resolve depositional variations in the central basin. This study aims to decipher the genetic mechanisms of evaporite precipitation and reconstruct the prototype basin’s tectono-sedimentary evolution by integrating high-quality 3D seismic data (2023), geophysical forward modeling, and palaeogeographic reconstructions. Integrated analyses revealed a distinct zoned “west halite-east gypsum/dolomite” pattern driven by paleosalinity gradients in a semi-closed lagoon system, alongside an elongated reef body in the middle ramp and thrombolite buildups in the inner ramp. Evaporite distribution was dominantly controlled by equatorial aridity (climate) and fault-induced differential subsidence (tectonics), with the latter creating thickness variations exceeding 300 m. This study establishes a genetic model of evaporite sedimentation under the Cambrian greenhouse conditions, providing analogues for coeval evaporite systems in Gondwana. The restored prototype basin configuration reveals salt-driven sediment partitioning processes, offering new insights into the tectono-sedimentary evolution of intracratonic basins. While seismic interpretations face limitations in deep zones with scarce drilling data, this framework guides future ultra-deep exploration targeting salt-tectonized traps below 8,000 m depth. • The evaporites within the Wusonggeer Formation predominantly comprise halite, gypsum, and dolomite. • Utilizing the latest three-dimensional seismic data, we have employed the root mean square amplitude attribute algorithm to accurately map the distribution of evaporites within the Wusonggeer Formation. • We developed a prototype basin model specifically applicable to the study area and created an animation that effectively illustrates the successive stages of the Wusonggeer Formation's deposition.