This dataset provides the data for the four glass standards used for monitoring of the precision and accuracy of electron probe microanalyses (EPMA) during analytical runs of cryptotephra glass-shards in the International Continental Scientific Drilling Program (ICDP) sediment core 5017-1 (see first dataset). For each EPMA run, all four glass standards were measured. The major-element composition of the glass standards was measured using a JEOL JXA-8230 electron microprobe at GFZ Potsdam, Germany (15 kV, 5-10 nA, 5-10 µm beam size). Instrumental calibration used natural mineral standards. Glass standards were Lipari obsidian (Hunt & Hill 1996, doi:10.1016/1040-6182(95)00088-7; Kuehn et al. 2011, doi:10.1016/j.quaint.2011.08.022) and MPI-Ding glasses ATHO-G, StHs-6-80-G and GOR-132-G (Jochum et al. 2006, doi:10.1029/2005GC001060).

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