The contribution of peat compaction to total basin subsidence: implications for the provision of accommodation space in organic‐rich deltas

摘要: ABSTRACT Provision of accommodation space for aggradation in Holocene deltaic basins is usually ascribed to eustatic sea‐level rise and/or land subsidence due isostasy, tectonics or sediment compaction. Whereas many deltas contain peat, the relative contribution peat compaction total has not yet been quantified from field data covering an entire delta. Subsidence potentially influences temporal and spatial sedimentation patterns, therefore alluvial architecture. Quantification amount rate was done based on (1) estimates initial dry bulk density derived a relation between organic‐matter content uncompacted samples (2) radiocarbon‐dated basal used reconstruct levels formation currently subsided samples. In Rhine‐Meuse delta, contributed considerably basin subsidence. Depending thickness compressible sequence, weight overburden up approximately 3 m 10‐m thick sequence calculated. Calculated local rates are 0.6 mm year−1, averaged over millennia, which twice estimated Holocene‐averaged 0.1–0.3 year−1 study area. Higher compaction, order few occur decades centuries, following substantial increase effective stress caused by loading. Without such stress, layers may accumulate thousands years with little Thus, delta variable time. Locally, 40% provided Implications large created are: increased trap efficiency deltas, decelerates progradation enhances relatively clastic sequences enhanced natural levees renewing existing space.