10.1594/PANGAEA.994127Ota, HayuHayuOta0009-0001-7029-2067Atmosphere and Ocean Research Institute, The University of TokyoKuroda, JunichiroJunichiroKuroda0000-0002-2218-4854Atmosphere and Ocean Research Institute, The University of TokyoOrihashi, YujiYujiOrihashi0000-0001-7715-3847Faculty of Science and Technology, Graduate School of Science and Technology, Hirosaki UniversitySchmitz, Mark DMark DSchmitz0000-0003-2888-0321Department of Geosciences, Boise State UniversityTakashima, ReishiReishiTakashima0000-0003-1830-6887The Center for Academic Resources and Archives, Tohoku University MuseumPANGAEA2026Cretaceous-Paleogene boundaryEast AsiaIODP³Osmiumzircon U-Pb geochronologyEvent labelSample code/labelSECTION, heightMain LithologyOsmiumOsmium, standard deviationRheniumRhenium, standard deviationOsmium-187/Osmium-188 ratioOsmium-187/Osmium-188 ratio, standard deviationOutcrop sampleNegative-thermal ionization mass spectrometer (N-TIMS), Thermo Fisher Scientific, TRITON XTInductively coupled plasma mass spectrometer (ICP-MS), Thermo Fisher Scientific Inc., iCAP TQCorrected, using the 187Os/188Os ratios for in situ decay of 187Re2015-08-27T00:00:00/2024-08-24T00:00:00Dataset10.1038/s43247-026-03602-z244 data pointstext/tab-separated-valuesCreative Commons Attribution 4.0 InternationalThis dataset contains osmium isotope ratios and osmium and rhenium concentrations from mudstone samples collected from the low-resolution interval of the Kawaruppu section, Nemuro Group, Hokkaido, Japan. The data cover the Upper Cretaceous-lower Paleogene interval across the Cretaceous-Paleogene boundary and were compiled for an integrated stratigraphic investigation of the boundary interval. Osmium isotope ratios and Os concentrations were measured by negative thermal ionization mass spectrometry (N-TIMS; TRITON, Thermo Fisher Scientific) and rhenium concentrations were measured by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS; iCAP Q, ThermoFisher Scientific) at Japan Agency for Marine-Earth Science and Technology (JAMSTEC).143.7273507143.731687443.0980550743.0987835Hokkaido, JapanJapan Society for the Promotion of Sciencehttps://doi.org/10.13039/50110000169117K05674High resolution age model and paleoenvironmental change for K/Pg boundaryJapan Society for the Promotion of Sciencehttps://doi.org/10.13039/50110000169118KK0091Improvement of Cretaceous Geologic Time ScaleJapan Society for the Promotion of Sciencehttps://doi.org/10.13039/50110000169121H04503Environmental changes during the Latest Cretaceous Mass Extinction Event recorded in the complete K/Pg boundary sequence discovered firstly in East AsiaJapan Society for the Promotion of Sciencehttps://doi.org/10.13039/50110000169122H01342The Cretaceous-Paleogene Boundary in the Southern Hemisphere: Osmium isotopic record to fingerprint flood basalt volcanismJapan Society for the Promotion of Sciencehttps://doi.org/10.13039/50110000169122K18426Linkage of the Earth's tipping points and the subseafloor biosphereJapan Society for the Promotion of Sciencehttps://doi.org/10.13039/50110000169123H00153Analysis of internal Earth nitrogen using pupulin nitrogen isotope ratioJapan Society for the Promotion of Sciencehttps://doi.org/10.13039/501100001691JPJSCCA20250004Warm-period Climate Change Research Center with the International Ocean Drilling School [WarmCCR]