HYDROGEN ISOTOPIC VALUES OF LONG-CHAIN DIOL ISOMERS IN SEDIMENTS ACROSS A SALINITY GRADIENT
J. Lattaud, Z. Erdem, D. Rush, M. Van der Meer, E. Hopmans, J. Sinninghe Damsté, G. Weiss and S. Schouten
Event name: 29th International Meeting on Organic Geochemistry
Publication date: 05 September 2019
Info: Extended abstract, PDF ( 174.59Kb )
Long-chain diols (LCDs) are widely used to reconstruct past environmental changes. They occur widespread in marine environments but also in lakes and rivers. The fractional abundance of the C32 1,15-diol can be used to infer the input of riverine LCDs but it is uncertain how the different LCDs are affected by this riverine input. Here we used the hydrogen isotope composition (δD) of LCDs to determine their source and to determine if the δD of LCDs is related to salinity. Surface sediments across a salinity gradient in the Gulf of Mexico were investigated. The LCD distribution is dominated by the C30 1,15-diol increases with increasing distance from the river mouth. On the contrary, the fractional abundance of the C32 1,15-diol decreases with increasing distance from the river mouth. Furthermore, δD ratios of the C30 1,15-diol and integrated C37:2 and C37:3 alkenones were more enriched with increasing salinity.