Abstract The Ofanto River drains volcanic rocks from the Monte Vulture, lacustrine–fluviolacustrine deposits associated with the same volcano and sedimentary deposits of the Southern Apennines and the Bradanic foredeep sequences. Comparing the modal composition of river sands and the outcrop area of different lithologies in the different sub-basins, an over-concentration of the volcaniclastic fraction, mainly represented by loose crystals of clinopyroxene, garnet and amphibole, is shown. This has been related to the preferential erosion of pyroclastic deposits, characterized by high production of sand-sized loose minerals, together with the carbonate lability and the low sand-sized detritus production from claystones and marls. The occurrence of volcaniclastic components upstream of Monte Vulture can be explained as a contribution from the lacustrine–fluviolacustrine deposits cropping out in the upstream sector or from pyroclastic fall deposits of Monte Vulture and/or Campanian volcanoes. This research shows that the volcanic record in the fluvial sands of the Ofanto River comes from weathering and sorting processes of volcaniclastic deposits rather than of the lavas building the main edifice. Therefore, caution must be taken during palaeoenvironmental and palaeoclimatic reconstructions when relating the type and abundance of the volcanic component in sediments to the weathering stage and evolutionary history of the volcano.

Abstract Sand and sandstone composition of volcanic origin may be clues to the provenance of the sediments and sedimentary rocks. Volcaniclastic provenance studies contribute significantly to unravelling the generation and provenance of sediment under investigation, which in the Aeolian archipelago comprises preserved units of outcrops dominated by lava flows intercalated with airfall tephras as source rocks. The focus of this paper is the study of the petrographical composition and textures of beach sands, which can then be used as a guide in the interpretation of provenance and origin of beach sand(stone)s rich in volcanic debris transported into deeper water. The composition of Aeolian beach deposits defines a single immature petrofacies with a large amount of unweathered glass and mafic minerals. Panarea island is dominated by dacites and new grain categories have been proposed to differentiate this provenance. Surface processes such as mechanical erosion (mass wasting and surface runoff) produce an overestimation of mafic components compared to the felsic components in the beach sand fraction.