We measured Sn, Fe and Hg content as well as grain size composition of soil cores and streambed samples from the floodplain of the Röslau River (Bavaria, Germany), in order to reconstruct the floodplain development and chemical antropogenic impacts. The samples were collected in 2023 and analysed in 2023/24 using aqua regia digestion and ICP-OES/ICP-MS to analyse the elemental composition. To prepare the samples, the sediment was sieved (2 mm) to discard the gravel fraction and large organic pieces. Further homogenisation was undertaken by grinding the samples with a vibratory mill. Grain sizes were obtained using a combination of sieving and laser diffraction (Microtrac particle analyser; Microtrac Retsch GmbH SYNC SN 0233).