Large-scale submarine landslide drives long-lasting regime shift in slope sediment deposition

Abstract Submarine landslides and associated mass-transport deposits (MTDs) modify the physiography of continental margins influence evolution submarine sediment routing systems. Previous studies highlighted control MTDs on subsequent sedimentary processes at spatial scales ranging from tens centimeters to few kilometers, leaving a knowledge gap how for long large-scale (i.e., headscarps wider than 50–100 km) may affect stratigraphic margins. To fill this gap, we used three-dimensional seismic reflection data tied an exploration well investigate impact one largest discovered Earth, Mafia mega-slide (Mms) offshore Tanzania, slope deposition. Seismic interpretation indicates that turbidite lobes/lobe complexes coalescent mixed turbidite-contourite systems formed pre-Mms stratigraphy between 38 ca. 21 Ma (age Mms), whereas coarser-grained sheet turbidites debrites accumulated after Mms ∼15 m.y., primarily topographic lows generated by emplacement landslide. We interpret drastic long-lasting regime shift in deposition be driven increase seafloor gradient capture focus feeding within broad failed area. propose extensive evacuation zones with such giant can generate major “conveyor belts”, trapping land-derived material or sediments transported along-slope as bottom currents. During progressive healing landslide escarpments, which last several million years, sand-prone facies are deposited upper slope, filling up accommodation space landslide, while deeper-water environments likely remain starved experience accumulation finer-grained deposits. Our study provides new insights into long-term response depositional landslides, implications transfer coarse-grained applied worldwide.