Provenance and sediment dispersal in the Po-Adriatic source-to-sink system unraveled by bulk-sediment geochemistry and its linkage to catchment geology

The Po-Adriatic region offers an excellent case for reconstructing sediment provenance and transport pathways of a multi-sourced sediment-routing system. Through comprehensive set ∼1400 geochemical data, model flux was built based on distinct compositional fingerprints 53 fluvial systems their comparison to coastal, shelf deep-marine sediments. Geochemically unique catchment lithologies (mafic/ultramafic rocks, limestones dolostones) were used as end-members assess exclusive source-rock signatures. Following calibration with sedimentary facies, selected key elements element ratios poorly sensitive particle size (Ni/Cr, MgO, Ni/Al2O3, Cr/V, Ca/Al2O3 Ce/V) adopted indicators. high-Ni high-Cr signature mafic/ultramafic rocks widely exposed in the Po River watershed along Albanian Dinarides contrasts markedly high-Ca (and locally high-Mg) composition Eastern Alpine, Apennine, Adriatic (Montenegro, Croatia, Slovenia) river catchments, which are, instead, carbonate-rich virtually ophiolite-free. Relatively high Ce values from Apulian samples serve marker minor, but very southern Apennine alkaline volcanic rocks. Despite along-shore mixing dilution sourced other muds primarily reflects eroded contiguous continental areas. Chromium-rich nickel-rich detritus generated mafic ultramafic complexes Western Alps conveyed through into Sea records signal that can be traced downstream long 1000 km, Alpine zone production area final deposition, offshore Apulia. While longitudinal dispersion linked general cyclonic, counter-clockwise circulation is prevailing Sea, conspicuous detrital input transversal deep sea revealed across using heavy metals tracers. Estimates loads fingerprinting fluvial, coastal sediments indicate previously neglected ophiolite-rich successions Albania represent major sediment-conveyor sinks (Southern Deep Mid-Adriatic Deep) significant cross-shore NNW-directed Sea. A cut-off value Ni/Cr ratio targeted around 0.8 represents effective tool differentiation marine Ni-rich (serpentine-rich) ophiolite origin sources affinity. High trace-metal contents found within basin are mostly natural only minimally reflect metal contamination.