Damming is a major geomorphological event characterized by catastrophic consequences and profound impacts on fluvial landscape evolution. Extensive Quaternary detrital deposits (DD) have been discovered in the Daju Basin. Some research suggests that these deposits are potentially associated with Great Flood events in the mainstream region. However, considering the multiplicity and complexity of the deposition, they may also result from catastrophic debris flows in local gullies. Consequently, we conducted a comprehensive investigation of detrital deposits and collected 64 provenance samples. The sediment provenance was analyzed by grain size distribution and elemental composition characterization. The results are as follows: (1) The detrital deposits in the basin are predominantly composed of sand and gravel, with some clay. (2) The results of the elemental ratios and multivariate statistical analysis confirmed the similarity in material composition between the detrital deposits in the basin and those from the Muduoluo Gully. (3) The discovery of palaeolandslides and lacustrine deposits in the study area indicates the existence of ancient dammed lakes and historical river damming events. The detrital deposits likely represent fan delta sediments formed by water-land interactions caused by damming events. Our study highlights new insights into discriminating the provenances of detrital deposits in localized regions, providing a new perspective for investigating geological hazards in the Jinsha River Basin.