The global database of deep-time marine nitrogen isotope data

Abstract. Stable nitrogen isotope records preserved in marine sediments provide critical insights into Earth’s climate history and biospheric evolution. Although numerous studies have documented nitrogen isotope (δ¹⁵N) records across varied geological ages (Archean to Recent) and paleogeographic settings, the scientific community remains constrained by the absence of a standardized database to systematically investigate their spatiotemporal evolution. Here, we present the database of Deep-time Sediment Nitrogen Isotopes in Marine Systems (DSMS-NI), a comprehensive global compilation of δ¹⁵N data and associated geochemical parameters, spanning a vast collection of sediment samples dating from the Recent to the Archean. This database encompasses 71 040 δ¹⁵N records derived from 424 publications, systematically organized with 29 metadata fields categories (e.g., chronostratigraphic ages, coordinates, lithology, metamorphic grade, sedimentary facies, references) encompassing 1 927 829 metadata. This repository further incorporates 130 proxy data fields, including 285 715 geochemical data spanning total organic carbon (TOC), total nitrogen (TN), and organic carbon isotopes (δ¹³C_org), major and trace elements and iron species. These integrated parameters enable evaluation of sample fidelity and factors influencing δ¹⁵N signatures. The DSMS-NI database will facilitate research across key geological intervals such as the Permian-Triassic boundary and the Cretaceous ocean anoxic events. Researchers can leverage temporal and paleogeographic information, alongside geochemical data, to conduct spatiotemporal analyses, thereby uncovering changes in deep-time marine nitrogen cycles and paleoenvironmental conditions. The database is open-access via the Geobiology portal (https://geobiologydata.cug.edu.cn/, last access: 30 April 2025), allowing users to access data and submit new entries to ensure continuous updates and expansion. This resource represents a vital foundation for studies in paleoclimate, paleoenvironment, and geochemistry, offering essential data for understanding long-term Earth-system processes. The data files described in this paper are available at https://doi.org/10.5281/zenodo.15117375 (Du et al., 2025a).