Scratch circles produced by redeposited Posidonia oceanica leaves on a contemporary beach of Favignana Island (off Western Sicily, Italy)

Scratch circles are circular or arcuate sedimentary structures formed by the rotation of an object anchored in or resting on a sediment surface under the influence of currents or wind. Although well documented in aeolian, tidal-flat, shallow-marine, and deep-marine environments, their occurrence in modern backshore settings has not yet been formally described. Here, the formation of scratch circles is reported on the backshore of Lido Burrone beach, Favignana Island (Egadi Archipelago, western Sicily), produced by redeposited leaves of the seagrass Posidonia oceanica . Individual leaves, partially buried at one end, rotated under light wind conditions and generated complete and incomplete circular grooves on fine-grained sand surfaces. The structures were documented in detail over two consecutive days, including shallow excavations at the anchoring points of the leaves. These observations demonstrate that scratch circles can form in low-energy beach environments and are not necessarily associated with plants rooted in situ. The described structures provide a modern analogue useful for the interpretation of similar circular sedimentary features in the geological record, particularly in marginal-marine and coastal settings.