The KIEL IV is a fully automated preparation device for the precise and accurate determination of oxygen and carbon isotope ratios in carbonates. The isotope ratio analysis of carbonate samples is increasingly important in paleoclimatic reconstructions involving biogenic carbonates such as foraminifera, bivalves, brachiopods, otoliths, and corals. Studies may involve growth zones of individual organisms or microfossils from drill cores. The KIEL IV carbonate device when coupled to a Thermo DELTA V or MAT 253 IRMS results in a system capable of highly sensitive, ultra-precise isotopic measurements in an automated, high-throughput workflow.