Salt-penetrating and non-salt-penetrating tear faults in central Tarim Basin

Abstract

We examined two tear faults, namely, Nos. 4 and 7 Faults, in Tarim Basin to investigate how a tear fault penetrates the salt layer. Using high-quality seismic data, we showed that No. 4 Fault penetrates the salt layer, whereas No. 7 Fault does not. We calculated the strata shortening data of Nos. 4 and 7 Faults. For No. 4 Fault, we observed shortening differences between the western and eastern sections in both the supra- and sub-salt strata, whereas for No. 7 Fault, we observed shortening differences only in the supra-salt strata. We demonstrated that under the action of thrusting, a tear fault could penetrate the salt layer if there is a shortening difference in the different positions of the sub-salt strata. A lack of shortening difference in the sub-salt strata implies that a tear fault cannot penetrate the salt layer, even though the sub-salt strata are deformed during thrusting.