AbstractsEarth & Environmental Science

The potential influence of downwashing on atmospherically deposited elements is of rare focus compared with other geochemical processes related to peat. Downwashing may cause a rapid downward movement of atmospherically supplied elements before they bond to the peat organic substrate and thus reduce the reliability of age-depth models that rely on atmospherically supplied radioisotopes (e.g. ²¹⁰Pb, ²⁴¹Am, ¹³⁷Cs). However, the existence of downwashing has not been directly tested, and to which depth the deposited element can be washed down is not fully understood. To address the question of downwashing, an experiment was set up to mimic wet deposition by applying a CuBr₂ solution during a three-week period in peat cores collected from Rödmossamyran. Through this, the experimental results clearly supported the existence of downward mobility. Added Cu²⁺ could be measured to a depth of 10 cm, similar to previous studies based on Be and Pb. As a similar metal to Cu, the age-depth model based on ²¹⁰Pb dating could underestimate the ages to some extent without consideration of downwashing.