Long-Distance Aeolian Dust Deposited on the Island of Crete (Greece): Detection, Characterization, and Provenance

Abstract

Long-distance aeolian dust transport represents one of the largest sediment fluxes on Earth, with North Africa being a dominant source. The island of Crete in the Eastern Mediterranean lies within major transport pathways but remains underexplored regarding multi-proxy fingerprinting of deposited dust. Here, we evaluate the contribution of long-range dust, sorting effects caused by the regional topography, and the contributions of different source areas on dust deposited in Crete over 15 months (03–2023 to 06–2024). We analyzed the bulk mineral, grain-size, and radiogenic (Nd, Pb, and Sr) isotope composition of monthly deposition samples at seven sites across western Crete as well as local surface material and reference aerosols from Libya. The deposited material is dominated by long-range transported dust originating from northern Africa, as indicated by the presence of palygorskite and distinct mineral and isotopic signatures from local surface sediments. Grain-size distributions are largely uniform across measurement sites and dominated by silts, with temporal rather than spatial variability controlling compositional changes. Isotopic data suggest major contributions from source areas in northeastern Algeria and north Libya to northwestern Egypt. The absence of gypsum and the variability of clay mineral proportions suggest transport related fractionation and mixing of multiple source regions. Shifts in mineral assemblages suggest changes in provenance from northeastern Algeria in winter to northeastern Libya and northwestern Egypt in summer. These results highlight the dynamic and seasonally variable nature of dust provenance in the Eastern Mediterranean and emphasize the value of integrating mineralogical and isotope approaches for robust source attribution.