Neotectonic movement feature and its controlling effect on accumulation in western Qaidam Basin

Since the late Himalayan Movement,neotectonic movements have been active and have played important roles on petroleum accumulation in the western Qaidam Basin.Based on the studies of outcrops,seismic profile geological tectonic interpretations and oil reservoir anatomies,combined with the previous research results,the features of neotectonic movements and their controlling effects on petroleum accumulations were discussed.The neotectonic movements resulted in the present regional unconformities in the Shizigou Formation and the NWW-oriented modern landscapes.During the neotectonic movements,deep faults activated again while new faults came into being,and 4 kinds of structural pattern were formed,including back thrust fault,propagation anticline,longitudinal bend anticline and detachment fold.The neotectonic movements promoted the formation of traps,and had controlling effects on petroleum charging and accumulations.Influenced by the neotectonic movements,the good matching of tectonic trap formation and petroleum charging as well as the weak destruction of fault on tectonic trap are favorable for petroleum accumulation.