Data report: organic matter, carbonate, and stable isotope stratigraphy from IODP Expedition 346 Sites U1426, U1427, and U1429

Abstract

Organic matter concentrations and organic carbon and nitrogen isotopes are reported for sediments drilled during Integrated Ocean Drilling Program Expedition 346. The Japan Sea/East Sea sediments from Sites U1426 and U1427 feature a range of total organic carbon (%TOC) between 0.16% and 6.36%, total nitrogen (%N) between 0.04% and 0.39%, δ13C values between –25.87‰ and –19.56‰, δ15N values between 3.33‰ and 13.08‰, and carbonate concentrations (%CaCO3) between 0% and 44.29%. The East China Sea sediments from Site U1429 feature a range of %TOC between 0.10% and 2.85%, %N between 0.02% and 1.22%, δ13C values between –24.74‰ and 17.73‰, δ15N values between 3.59‰ and 13.40‰, and %CaCO3 between 0.70% and 42.84%. Both organic matter content and stable isotopes are well correlated with b* sediment color reflectance values and infer decreased surface productivity and suboxic to anoxic environments during glacial periods and increased productivity and deep-water ventilation during interglacial periods in the Japan Sea/East Sea.