Biomarker and XRF scanning data from IODP Site 350-U1437B: a study of paleoceanographic and paleoclimatic changes in the Northwest Pacific Ocean over the past 1 Ma

DOI

Sediment core U1437B was drilled during International Ocean Discovery Program Expedition 350 in 2014. The aim of this study was to infer information on the paleoclimatic and paleoceanographic evolution of the Northwest Pacific Ocean and adjacent East Asian continent over the past 1 Ma. For this, 174 freeze-dried and homogenized sediment samples from Site U1437 Hole B were extracted using a solvent mixture of dichloromethane:methanol (93:7, v:v) at elevated temperature (75° ) and pressure (50 bar) using a Büchi Speed Extractor (Büchi, Switzerland). Total lipid extracts were desulfurized and an aliquot with an added standard mixture was measured on an Agilent 7980 gas chromatograph (GC) coupled to an Agilent 5975 mass spectrometer (MS) to quantify long- chain n-alkanes, n-alcohols, and nonacosan-10-ol. Another aliquot of the total lipid extracts was separated into apolar, ketone and polar fractions using column chromatography. The ketone-bearing fractions were subsequently measured on an Agilent 7980 GC coupled to an Agilent 5975 MS (Agilent, Germany). The polar fractions were analyzed by high performance liquid chromatography coupled to mass spectrometry (HPLC/MS) using an Alliance 2690 HPLC (Waters, UK) and a Quattro LC triple quadrupole MS (Micromass, UK) to measure glycerol dialkyl glycerol tetraethers (GDGTs). Total organic carbon contents were determined on 200 mg decarbonized sediment powder using an ELTRA CS- 580A elemental analyzer. Additionally, sections 350-U1437B-1H-1A to 17F-4A, comprising the uppermost 120 m of Hole B and corresponding to the past 1 Ma, were scanned using an ITRAX micro-X-ray fluorescence (XRF) core scanner at Kochi Core Center, Japan. XRF spectra were generated every 2 cm with an exposure time of 60 sec. The X-ray beam was generated with a 3 kW Mo tube run at 30 kV and 55 mA. Sea surface temperature estimates calculated from the unsaturated ketone index (UK'37) and GDGT- based tetraether index (TEX86) as well as GDGT-based methane index (MI) and branched and isoprenoid tetraether index (BIT) values are reported in Dataset S1. Dataset S2 contains summed concentrations of long-chain n-alkanes, n-alcohols and nonacosan-10- ol, as well as mass accumulation rates of TOC and C37 alkenones, which were calculated using linear sedimentation rates, alkenone or TOC contents, and dry bulk densities from shipboard measurements (Tamura et al., 2015). Fractional abundances of individual GDGTs and C37 ketones are reported in Dataset S3. Dataset S4 comprises ratios of selected elements calculated from XRF scanning measurements on core sections of the uppermost 120 meters below seafloor of Site U1437 Hole B.

Identifier
DOI https://doi.org/10.1594/PANGAEA.950517
Related Identifier IsSupplementTo https://doi.org/10.1016/j.gloplacha.2023.104173
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.950517
Provenance
Creator Jonas, Ann-Sophie ORCID logo; Kars, Myriam ORCID logo; Bauersachs, Thorsten ORCID logo; Ruebsam, Wolfgang; Schwark, Lorenz ORCID logo
Publisher PANGAEA
Publication Year 2023
Funding Reference German Research Foundation https://doi.org/10.13039/501100001659 Crossref Funder ID SCHW 554/27-1,2 Paleoclimate evolution in the Northwest Pacific over the last 25 Ma
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Resource Type Bundled Publication of Datasets; Collection
Format application/zip
Size 4 datasets
Discipline Earth System Research
Spatial Coverage (139.026W, 31.790S, 139.026E, 31.790N)
Temporal Coverage Begin 2014-04-11T01:35:00Z
Temporal Coverage End 2014-04-13T21:45:00Z