The North Dabashan Mountain, an important part of the South Qinling orogenic belt, holds well preserved sedimentary records. For a long time, the Banjiuguan Formation was considered to have formed in a relatively stable tectonic setting. In this paper, sedimentary successions and geochemical analyses are used to determine its provenance and tectonic setting. The Banjiuguan Formation consists of finegrained sandstones, siltstones and mudstones deposited in deep waters. Facies assemblages indicate that they were deposited in a submarine fan environment. Paleocurrent data preserved in cross bedding indicates that sediments were proximally derived from north. Chemical classification of the Banjiuguan sandstones shows that the analyzed sediments are mostly litharenite. The REE patterns are characterized by LREE enrichment, flat HREE, and negative Eu anomalies. Chemical Index of Alteration range from 51 to 67, and Th/U ratio is 3. 36 to 7. 02, both of which suggest weak weathering. The rations of Zr/Sc and Th/Sc further show that the sandstone experienced no reworking. Various plots and parameters for sedimentary provenance show that the sediments were sourced predominantly from felsic rocks. Geochemical data suggest that they were deposited in an environment related to continental island arc setting and passive continental margin.