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International audience; During the Late Pleistocene, an ice cap temporarily rested on the highest summit of the Black Forest, Feldberg, and on the surrounding region. Moraines inside the last glaciation maximum ice extent document subsequent glacial standstills and/or re-advances, but the chronology of the deglaciation remains largely unknown. In Sankt Wilhelmer Tal, moraines were mapped, and suitable moraine boulders were sampled for 10 Be cosmic ray exposure (CRE) dating. Equilibrium line altitudes (ELAs) during moraine formation were reconstructed to evaluate whether these can be used for local stratigraphical correlations. Geomorphological mapping revealed numerous icemarginal positions in the main valley and in two tributary valleys. CRE ages and ELAs indicate two discrete phases of glacial standstills and/or re-advances by 17-16 ka at the latest and no later than 14 ka, respectively. Differing ELAs across the study area preclude the use of ELAs for local stratigraphical correlations. Recalculated 10 Be CRE ages from other localities in Central Europe indicate similar periods of moraine formation, thus raising the question of a common climatic forcing. Additional sets of CRE ages are needed to answer this question. In addition, future studies should concentrate on determining the age of the last glaciation maximum in the Black Forest.

Cosmic-ray exposure (CRE) dating of boulders on terminal moraines has become a well-established technique to reconstruct glacier chronologies. If topographic obstructions are present in the surroundings of sampling sites, CRE ages need to be corrected for topographic shielding. In recent years, geographical information system (GIS)-based approaches have been developed to compute shielding factors with elevation data, particularly two toolboxes for the ESRI ArcGIS software. So far, the output of the most recent toolbox (Li, 2018) has only been validated with a limited number of field-data-based shielding factors. Additionally, it has not been systematically evaluated how the spatial resolution of the input elevation data affects the output of the toolbox and whether a correction for vegetation leads to considerably more precise shielding factors. This paper addresses these issues by assessing the output of the toolbox with an extensive set of field-data-based shielding factors. Commonly used elevation data with different spatial resolutions were tested as input. To assess the impact of the different methods on CRE ages, ages of boulders with different 10Be concentrations at sites with varying topography and 10Be production rates were first recalculated with GIS-based shielding factors and then with field-data-based shielding factors. For sampling sites in forested low mountainous areas and in high Alpine settings, the shielding factors were independent of the spatial resolution of the input elevation data. Vegetation-corrected elevation data allowed more precise shielding factors to be computed for sites in a forested low mountainous area. In most cases, recalculating CRE ages of the same sampling sites with different shielding factors led to age shifts between 0 % and 2 %. Only one age changed by 5 %. It is shown that the use of elevation data with a very high resolution requires precise x and y coordinates of sampling sites and that there is otherwise a risk that small-scale objects in the vicinity of sampling sites will be misinterpreted as topographic barriers. Overall, the toolbox provides an interesting avenue for the determination of shielding factors. Together with the guidelines presented here, it should be more widely used.