Ruben Zeitler conducted his bachelor thesis on the use of XRF-Core Scanning of corals to test the technology for the study of speleothems and tropical corals. In coopreration with the Earth sciences Ca and Sr could be detected well in both archives. Focusing on the more promising coral using optimal measurement settings of voltage, current, count time, and slit size 400 mm long record of Sr/Ca was achieved. Based on a strong correlation between Sr/Ca and Si (and Al) a seasonal input of detrital sediment from the coast was suspected. Porosity and heterogenity of the samples place strong limitations to the use of this technology. We congratulate Ruben for his excellent results and whish you all the best for the future.