Organic carbon, bulk nitrogen isotope and bulk sulfur isotope and abundance data and metal abundance data from metapelites of the 3.7Ga Isua Supracrustal Belt. For more details, see Stüeken, E.E., Boocock, T., Szilas, K., Mikhail, S. and Gardiner, N.J., 2021. Reconstructing nitrogen sources to Earth’s earliest biosphere at 3.7 Ga. Frontiers in Earth Science, 9, p.675726.