Publication Date:
2024-02-05
Description:
Hydrogen isotope composition of aquatic (mid-chain n-alkenes, C20-HBIs, C37-alkenones) and terrestrial (long-chain n-alkanes) biomarker groups were analysed in core H7 from Hala Hu, China. The lake is located on the northern margin of the Tibetan Plateau (97.24 - 97.47°E, 38.12 - 38.25°N, 4078 m above sea level), along the modern marginal zone between the Asian Summer Monsoon (ASM) and westerlies influences. The core was drilled at the deepest point (65 m) of the lake and extends from 212 to 636 cm sediment depth. According to the age-model (Yan et al., 2020) the covered time period is 7462 - 23610 cal yr BP.
After quantification of compounds, for separate δD-analysis of n-alkanes and n-alkenes, the non-polar aliphatic fraction was further split chromatographically into a saturated and unsaturated fraction, using aluminum-coated silicagel as stationary phase and hexane and DCM as solvents. To obtain sufficient amounts for isotope analysis, in some cases several samples have been merged, especially in the older section of the core. Compound specific hydrogen isotope values were then obtained by using gas chromatography isotope ratio mass spectrometry (GC-IRMS). We used a Thermo Scientific® Trace GC equipped with a Restek RTX-5 column (30 m, inner diameter 0.25 mm, film thickness 0.25 μm). The GC was connected via a GC Isolink with high temperature combustion furnace (1400 °C) and a Conflo IV interface to a Delta V Plus isotope ratio mass spectrometer.
The δD values of the alkenones were determined by a GC/Thermal Conversion/isotope ratio monitoring mass spectrometer (GC-TC-irMS). For this a GC, equipped with a CPsil 5 CB column (25 meters, 0.32 mm inner diameter, film thickness 0.4 μm) was coupled to a GC-isolink I via a Conflo IV to a Thermo Electron DELTA V mass spectrometer.
Keywords:
Alkenone; Biomarker; Calendar age; Calendar age, maximum/old; Calendar age, minimum/young; China; Comment; DEPTH, sediment/rock; Gas chromatography - Isotope ratio mass spectrometer (GC-IRMS); Gas chromatography - thermal conversion - isotope ratio monitoring mass spectometer (GC-TC-irMS); H7; Hala_Hu_2010-H7; Hala Hu; highly branched isoprenoid (HBI); isotopes; n-alkane; n-Alkane C29, δD; n-Alkane C29, δD, standard deviation; n-Alkane C31, δD; n-Alkane C31, δD, standard deviation; n-alkene; n-Alkene C23:1, δD; n-Alkene C23:1, δD, standard deviation; n-Alkene C25:1, δD; n-Alkene C25:1, δD, standard deviation; n-Alkene C27:1, δD; n-Alkene C27:1, δD, standard deviation; Niederreiter Piston corer; NPC; Paleoclimate; Sediment core; Sum alkenones C37, δD; Sum alkenones C37, δD, standard deviation; Tibetan Plateau
Type:
Dataset
Format:
text/tab-separated-values, 438 data points
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