Concentrations of biomarkers (aliphatic fraction) in Hala Hu sediment core H7

Concentrations of aquatic (mid-chain n-alkenes, C20-HBIs) and terrestrial (long-chain n-alkanes) biomarker groups were analysed in core H7 from Hala Hu, China. The compounds were quantified relative to an internal standard (5α-androstane) using an Agilent 7890A gas chromatography (GC) instrument, equipped with a mass selective detector (MSD; Agilent 5975C Series) and a flame ionization detector (FID; Agilent 7683B Series). For the GC, a Restek DB-5 column (30 m, inner diameter 0.25 mm, film thickness 0.25 μm) was used.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.