In the former GDR, investigations were carried out between 1980 and 1990 to estimate the raw material potential in the pre-Upper Permian bedrock units (Flechtingen-Rosslau Hills, Harz Mountains, Saxon Granulite Mountains, Thuringian Forest, Thuringian-Vogtlandian Slate Mountains, Ore Mountains, Elbe Valley Region/Lusatia), which lie at the earth's surface or are slightly covered by the Cenozoic. Part of these investigations was a geochemical prospection in the area of the above mentioned bedrock units. Approximately 18,000 water and 17,500 stream sediment samples were taken and geochemically analysed over an area of almost 15,000 km². The results of these investigations were documented in sub-reports on the individual bedrock units as well as in the "Final Report on the Comparative Evaluation of the Raw Material Potential in the Bedrock Units of the GDR" (Röllig et al., 1990; in German). These data from the bedrock units in the southern part of the former GDR are unique in their high sampling density (> 1 sample/km²) and provide a comprehensive geochemical survey of these areas. All later geochemical investigations (Geochemical Atlas 2000 as well as within the framework of GEMAS and FOREGS) were carried out with a much lower sampling density. These valuable and irretrievable data are now made generally available via the BGR geoportal. In addition to the digital provision of the original data material, area-wide distribution maps are made available for the first time, which were generated using modern computer-assisted methods. The downloads show the distribution of Yttrium contents in stream sediments in four different coloured point and colour shaded contour maps.