Monte Carlo uncertainty calculation of 210Pb chronologies and accumulation rates of sediments and peat bogs

Abstract

210Pb dating is a key technique to study sedimentary records of environmental change in the Anthropocene over a time scale of 100–150 years. Uncertainty estimation of 210Pb ages and accumulation rates, when provided by the authors, are usually based on quadratic propagation of uncertainties. In this work, we describe the use of Monte Carlo simulation to estimate 210Pb dating uncertainties in sediment and peat cores. The methodology allows, by using nowadays common computers, the assessment of 210Pb dating uncertainties in a simple manner, using readily-accessible computers and widely-used proprietary spreadsheet software, and avoiding the derivation of rather complex formulae. Results were calculated and compared with quadratic propagation uncertainties in a marine, lacustrine and peat bog core. The analysis of the uncertainty budgets indicated that, overall, the total and unsupported (or base) 210Pb concentrations are the largest contributors to uncertainty, as well as the layer depths when sediment accumulation rates were calculated. Beyond 210Pb dating, the Monte Carlo scheme described here could be used in any field of the analytical sciences, including other radiochronological applications.