Evidence that excess 210Pb flux varies with sediment accumulation rate and implications for dating recent sediments

摘要: Most 210Pb dating models assume that atmospheric flux of excess (210Pbexc) to the sediment–water interface remains constant over time. We revisited this assumption using statistical analysis a database laminated sediments and evaluated implications for radiometric recent deposits. A bibliographic survey enabled us create with 10 annually sediment cores from variety aquatic systems. The has records 210Pbexc flux, initial activity, accumulation rate (SAR). varied time, 1/3 data had relative deviations mean value >25 %. There was no statistically significant correlation between activities at core top SAR, whereas (p < 0.01) linear regression SAR found nine ten cores. Thus, in most studied systems, governed primarily by matter, rather than direct deposition. Errors chronology attributable varying estimated supply (CRS) model, were its analytical solutions, tested against values derived independently varves. identified several constraints general application CRS which must be taken into account avoid misuse.