ABSTRACT
Older rift basins, which were deeply buried and reworked by advancing fold-thrust belts, offer potential opportunities for hydrocarbon accumulation, but capturing and defining them can be challenging. This study uses reprocessed two-dimensional seismic data sets, offering unprecedented insight into a buried Neoproterozoic rift basin within the Cenozoic Kalpin fold-thrust belt (KFTB). The results reveal a Neoproterozoic rift basin characterized by strong, dipping reflectors at its base and multiple unconformable reflection interfaces at its top, outlining the synrift wedge. The rift and its associated faults predominantly exhibit east-west and northeast trends, suggesting a potential linkage to the northern rift system in the Tarim Basin. In addition, several anticlines, driven by the uplift of lower Cambrian strong reflectors above the regional elevation, are identified as rift inversion structures formed after the overlying thin-skinned deformation. Consequently, the structural style of the KFTB is redefined as Cenozoic thin-skinned tectonics involving Neoproterozoic rift inversion. This redefinition highlights several significant structural traps beneath the thrust sheets. These buried structures under the thrust nappes shed new light on deep hydrocarbon resources, encouraging a renewed assessment and unlocking the exploration potential of fold-thrust belts.