摘要
Based on analysis of drilling, logging and field profile data, six sequence boundaries in Permian are identified in Bachu and Tazhong regions of Tarim Basin. All sequence boundaries are of type I sequence bound- aries, and are characterized by down cut. According to the six sequence boundaries, the Permian in this area can be divided into 5 third-order sequences, and all the sequences correspond with classic sequence model of Vail. Sequence Psq4 indicates lake transgressive system tract （TST） and highstand system tract （HST）. Se- quences Psql, Psq2, Psq3, Psq5 indicate low stand system tract （ LST）, transgressive system tract and high- stand system tract. LST is deposited by incised channel infilling with features of fluvial facies. TST is deposited by shore-shallow lake and semi-deep lake. HST is deposited by semi-deep lake, shore-shallow lake and delta. In addition, volcanic rocks are present on the top part of HST in sequence Psq3. Incised channel infilling and deltaic deposits were mainly distributed on western slope of Tadong uplift.
Based on analysis of drilling, logging and field profile data, six sequence boundaries in Permian are identified in Bachu and Tazhong regions of Tarim Basin. All sequence boundaries are of type I sequence boundaries, and are characterized by down cut. According to the six sequence boundaries, the Permian in this area can be divided into 5 third-order sequences, and all the sequences correspond with classic sequence model of Vail. Sequence Psq4 indicates lake transgressive system tract (TST) and highstand system tract (HST). Sequences Psq1, Psq2, Psq3, Psq5 indicate low stand system tract (LST), transgressive system tract and highstand system tract. LST is deposited by incised channel infilling with features of fluvial facies. TST is deposited by shore-shallow lake and semi-deep lake. HST is deposited by semi-deep lake, shore-shallow lake and delta. In addition, volcanic rocks are present on the top part of HST in sequence Psq3. Incised channel infilling and deltaic deposits were mainly distributed on western slope of Tadong uplift.
