Sampling statistic limitations on benthic foraminifera chemical and isotopic data

摘要: Abstract Analyses of benthic foraminiferal isotopic and chemical properties are typically done on a small number individuals (often 5–10). Because sediment mixing produces mix whose were determined at times encompassing several thousand years, sampling does not adequately represent the average mixture. A quantitative statistical analysis shows that this effect places fundamental limit measurement precision in cores, especially where rapid environmental changes occur over short vertical distances. The parameters defining rate change property (per unit distance) effective depth. In cores found Vema Channel/Rio Grande Rise region, sedimentation rates about 1 cm ka −1 depths 3 cm, single six can produce result has an expected one sigma standard deviation 6–25% observed range. Precision be improved by using more or running replicate analyses, but only improves as square root replicates. This is illustrated Cd Ca data from low (0.7 ) moderate (1.5 cores. Although compromised most contributes to imprecision high well.