Fine identification of sedimentary boundary of different provenance systems——Taking Neogene Shawan formation in Chepaizi uplift as an example

As for different provenance systems of Neogene Shawan formation in eastern Chepaizi uplift, there are typical differences in lithology, sedimentary fabric, logging and seismic reflection characteristics. The south provenance system mainly develops braided river deltas, and the lithology is dominated by feldspathic lithic sandstone, which is the tractive current deposition over a long distance. The electrical curve has typical sandstone response characteristics, and the seismic waves show strong reflection characteristics. In the north provenance system, fan deltas near provenance deposits are mainly developed, the lithology is dominated by lithic arkose sandstone, which is a typical gravity flow deposition. The sandstone response characteristics of electrical curves are not obvious, and seismic waves are weak-blank reflection. Then, the effective identification of the south and north provenance systems was carried out, and the affected range of different provenance systems in the sedimentary junction was implemented. The lithological traps at the sedimentary junction of the two provenance systems are described in detail, and the fine identification of sedimentary boundary of different provenance systems is realized, which obtained good exploration results.