Variation of ocean sediment thickness with crustal age

Abstract

AbstractGlobal ocean sediment thickness and present‐day ocean sediment accumulation rates are analyzed with respect to the age of the underlying ocean crust. Trends in average sediment thickness and present‐day accumulation rate are well fit by cubic polynomials in crustal age for the global ocean and for individual ocean basins. Sediment thickness and accumulation rates are larger in the North and South Atlantic and Indian Oceans compared to the Pacific Ocean, primarily because the anomalous sediment accumulations that followed continental rifting and collision in the Atlantic and Indian Ocean basins are missing in the Pacific Ocean. Modern ocean sediment accumulation rates, extrapolated into the past assuming steady state conditions, account within uncertainties for the global average sediment thickness on 0–65 Ma (Cenozoic age) ocean crust, while the profile of anomalously thick sediments on older (Mesozoic age) ocean crust is well fit by adding localized, diffusive sediment transport from a steady state source referenced to the adjacent continental margin. Apart from a distinct 0–5 Ma (Quaternary age) sediment pulse, deviations in average sediment thickness from this simple model are generally small and are uncorrelated across ocean basins.