Advances and Prospects in Sediment Provenance Studies of Small- and Medium-Sized Rivers on the Southeastern Coast of China

Small- and medium-sized rivers in the southeastern coastal region of China serve as critical sediment transport pathways connecting continents to marginal seas, and studies of their provenance are important for understanding regional source-to-sink processes. However, provenance research on eastern Chinese rivers has long focused on large rivers such as the Yangtze and Yellow Rivers, while the small- and medium-sized rivers along the southeastern coast remain understudied. The sediment production of these mountainous rivers is jointly influenced by basin geology, climate, hydrodynamics, and human activities. In some local areas, their sediment fluxes to the sea even exceed those of large rivers in terms of contribution to nearshore deposition. Therefore, investigating their provenance and source-to-sink processes is of great importance for tracing the evolution of sediment provenance in marginal seas. This paper reviews the progress of provenance studies on small- and medium-sized rivers in the southeastern coastal region of China; summarizes major tracing methods including detrital zircon U-Pb geochronology, geochemistry, mineralogy, and sedimentology; and highlights the provenance differences between the small- and medium-sized rivers in the Zhejiang–Fujian region and those in the Taiwan region, as well as their spatial contribution patterns to the southeastern coastal area. Based on current research limitations, future directions are proposed, including the integrated application of multiple provenance tracing methods, the development of technical systems to disentangle the superimposed effects of natural and anthropogenic influences, and the construction of quantitative multi-end-member mixing discrimination. This review aims to provide a scientific basis for research on regional sediment provenance evolution.