| Abstract
| - Ombrotrophic peat bogs have been widely used toevaluate long-term records of atmospheric mercury (Hg)deposition. One of the major aims of these investigations isthe estimation of the increase in atmospheric Hg fluxesduring the industrial age compared to preindustrial fluxes.Comparability of Hg accumulation rates calculated fromdensity, peat accumulation rates, and Hg concentrationsrequires linearity between these parameters. Peat formationis a dynamic process accompanied by intense mass lossand alteration of the organic material. Our investigations onthree peat cores from the Magellanic Moorlands, Chile,indicate that Hg concentrations in peat strongly depend onpeat humification. Moreover, differences in massaccumulation rates during peat evolution are not compensatedby linear changes in density, peat accumulation, or Hgconcentrations. We suggest that Hg accumulation rates benormalized to carbon accumulation rates to achievecomparability of Hg accumulation rates derived fromdifferently altered peat sections. Normalization to the carbonaccumulation rates reduces Hg accumulation rates inless degraded peat sections in the upper peat layers byfactors of more than 2. Our results suggest that the increasein Hg deposition rates during modern times derived fromombrotrophic peat bogs are potentially overestimated if Hgaccumulation rates are not corrected for mass accumulationrates.
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