Organic sources and carbon sequestration in Holocene shelf sediments from the western Arctic Ocean

► N. Chukchi Sea sediments covering 9000 yr of the Holocene period were analyzed. ► Organic biomarkers indicate marine sources as the dominant input of organic matter. ► Lower but continual contributions from terrestrial sources were also determined. ► There was remarkable consistency among multiple molecular organic markers down-core. ► The consistency suggests influence by bottom currents and mixing before deposition.