Abstract The provenance of Llandeilo to upper Llandovery sediments from the Welsh Basin has been investigated by petrographic and geochemical methods. Sandstone-dominated formations were deposited from high-concentration turbidity currents. Petrographic data suggest derivation from a non-collisional recycled or cratonic setting. This is broadly confirmed by analysis of microconglomerate lithic fragments and the major element geochemistry. Mudstone-dominated formations were deposited from dilute turbidity currents and as hemipelagic sediments. The mudstone geochemistry indicates a tectonic setting transitional between an active continental margin and a passive margin. This study demonstrates that neither set of analytical methods are individually adequate for provenance reconstruction and it is advisable to use a variety of techniques for greater confidence in interpretation.