The elemental composition of samples from four sediment cores from the Mayschoß floodplain (Ahr river) was determined by X-ray fluorescence spectrometry (XRF). In the first step of preparation, large organic matter and pebbles were removed from freeze-dried samples (8 g) by sieving (2 mm). Subsequently, the samples were powdered and homogenised with vibratory Retsch mill MM 200. The uniform pills for the analysis were pressed with a carbon-based binding agent by Vaneox press at 20 t for 2 min. The elemental analysis of 50 elements was conducted in a He atmosphere using a Spectro Xepos energy dispersive XRF spectrometer. The surface elevation was extracted from Brell et al. (2023).