The influence of lateral transport on sedimentary alkenone paleoproxy signals

Abstract. Alkenone signatures preserved in marine sedimentary records are considered one of the most robust paleothermometers available and often used as a proxy for paleoproductivity. However, important gaps remain regarding provenance fate alkenones, well their impact on derived environmental signals sediments. Here, we analyze abundance, distribution radiocarbon (14C) age alkenones bulk sediments corresponding grain-size fractions surficial from seven continental margin settings Pacific Atlantic oceans to evaluate organo-mineral associations hydrodynamic sorting alkenone signals. We find that preferentially reside within fine-grained mineral sediments, with preponderance residing fine-silt fraction (2–10 µm) strongly influencing alkenone-14C sea surface temperature (SST) consequence proportional abundance higher degree organic matter protection relative other fractions. Our results provide further evidence key role selective association surfaces associated processes reliability encoded (14C age, content distribution) fidelity (productivity SST) spatial temporal domain.