Investigating the Timescale of Weathering Signals Preserved in Marine Sediments—Insights From the Holocene Mediterranean

The climate–weathering feedback exerts a vital role in long‐term planetary habitability. However, its operational timescales remain unclear due to challenges in quantifying past weathering intensity, especially in marine sediments—the final sink of continental weathering fluxes. Using Holocene Mediterranean sediments as a test case, we examine climate‐driven weathering responses recorded in deep‐sea archives. Geochemical analyses of 18 well‐dated eastern Mediterranean cores reveal distinct provenance‐controlled weathering signals. After accounting for provenance and grain‐size effects using fixed‐effects models, we identify a consistent pattern between climate changes and weathering responses, with a time lag of ∼3,000–5,000 years. The observed lag varies by depositional setting, requiring up to 2,000 years for marine sediment transit from nearshore to abyssal environments. Catchment erosion and transport introduce another ∼3,000‐year delay, reflecting hydroclimate instability influences on weathering dynamics. Consequently, deep‐sea archives effectively preserve climate‐driven weathering changes only on timescales exceeding sediment residence time (generally >103 years).