U-series dating at Nerja cave reveal open system. Questioning the Neanderthal origin of Spanish rock art

U/Th data obtained on CaCO3 layers covering rock art at Nerja Cave (Spain) evidence erroneous ages and an inverse relation between uranium concentration and apparent ages. This open system behavior could be due to a mechanism causing uranium mobility, resulting in apparent ages being too old with respect to their real age. This article also questions recently published U/Th data on samples from Ardales, Maltravieso and La Pasiega caves (Spain) where a few U/Th ages older than 40 ka BP, suggested that cave art could be attributed to Middle Palaeolithic population (Hoffmann et al., 2018). For these caves, U/Th data also display an inverse relation between U content and ages, indicating possible uranium mobility and erroneous ages. •U/Th data were obtained on CaCO3 layers covering rock art at Nerja cave (Spain).•Inverse relation between U content and ages, suggest U mobility and wrong ages.•An inverse relation between U content and U/Th exists for previously published data.•The validity of old U/Th ages on spanish rock art published previously is questioned.