The global Deep-time Sediment Nitrogen Isotopes in Marine Systems (DSMS-NI) database

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 for various geological systems (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 70 854 δ¹⁵N records derived from 417 publications, systematically organized with 31 metadata fields categories (e.g., chronostratigraphic ages, coordinates, lithology, metamorphic grade, sedimentary facies, references) encompassing 1 999 226 metadata. This repository further incorporates 130 proxy data fields, including 281 215 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 for key geological intervals such as the Permian/Triassic boundary and the Cretaceous oceanic anoxic events (OAEs). 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).