The dataset contains three subsets: 1) W isotope data for reference materials and geological samples, 2) Pb isotope data for reference materials and geological samples and 3) Mo isotope data for reference materials and geological samples. The data was collected over a period of about two years in two different laboratories (University of Manchester and University of Bristol) using multi-collector ICPMS techniques. A description of the methods used to obtain the W and Mo isotope data can be found in Willbold et al. (2011) and Willbold et al. (2016). The determination of the Pb isotope data is detailed in Freymuth et al. (2016). The data of reference materials (standard solutions and geological reference materials) is used to assess the reproducibility and accuracy of the mass spectrometric setup at the time and used as uncertainty estimate for the geological sample data. References: Freymuth, H., Elliott, T., van Soest, M., Skora, S., 2016. Tracing subducted black shales in the Lesser Antilles arc using molybdenum isotope ratios. Geology 44, 987-990. Willbold, M., Elliott, T., Moorbath, S., 2011. The tungsten isotopic composition of the Earth's mantle before the terminal bombardment. Nature 477, 195-198. Willbold, M., Hibbert, K., Lai, Y.-J., Freymuth, H., Hin, R.C., Coath, C., Vils, F., Elliott, T., 2016. High-Precision Mass-Dependent Molybdenum Isotope Variations in Magmatic Rocks Determined by Double-Spike MC-ICP-MS. Geostandards and Geoanalytical Research 40, 389-403.