Linkage and formation of strike-slip faults in deep basins and the implications for petroleum accumulation: A case study from the Shunbei area of the Tarim Basin, China

Linkage of fault segments is a critical process during the forma-tion of strike-slip faults, and it influences the generation and dis-tribution of related structures. In this study, we investigate the linkage processes and formation mechanism for the strike-slip faults in the Shunbei area of the Tarim Basin based upon newly acquired three-dimensional seismic data. The seismic interpreta-tions suggest that the northeast-trending SB-1 fault and the approximately north-trending SB-5 fault are strike-slip faults with the development of superimposed flower structures in the cross-section views. In the plan view, segments of these faults show a step-like arrangement. We infer that the main activities of these strike-slip faults took place in the Middle and Late Ordovician. The linkage underwent two phases. The first phase was the linkage of R and P shears along with different segments by forming principal displacement zones. The second phase was the linkage of different segments by forming overstepped zones, culminating in the flower structures. Overall, under the influ-ence of the subduction of the Paleo-Asian and Proto-Tethys oceans and the orogenesis surrounding the Tarim craton, the for-mation of the strike-slip faults in the Shunbei area experienced three stages, including the initial stage in the Cambrian, the highly developed stage in the Middle and Late Ordovician, and the weak activity stage from the Silurian to the early Carbonifer-ous. Through fault linkage, the damaged area of the fault segments was enlarged, with the presence of the overstepped zones and complex internal architectures, which provided efficient pathways for fluid migration.