Sediments occurring in clastic depositional coastal and marine environments share similar sedimentary characteristics despite their different provenances. Identifying the deposits' origin found at a specific site may be essential, but also a challenging task. This paper discusses a fast methodology to recognise the primary source of sediments using end-member modelling, applied specifically to particle shape distributions instead of the classical approach of using grain-size distributions only. Artificial mixtures of coastal cliff and nourished sediments from Sylt Island (North Sea) were measured with a dynamic image analyser. Roundness, sphericity, convexity, and aspect ratio shape descriptors were analysed using the EMMAgeo R-based algorithm to compare mixtures to original sediments. Roundness distribution appeared to be a useful shape descriptor for distinguishing nourished sediments and their content in mixed samples. This method may be applied for future sediment pathway analyses, e.g., for tracking nourishment materials.