> Research > Programs and projects > Theme 1 & 2

Impact of post-depositional processes on organic proxies
Project leader: Prof. dr. ir. S. Schouten
Researcher(s): MSc S. Lengger
Starting date: 1-11-2008

Abstract
Organic compounds present in the sedimentary archive can be used as proxies for reconstructing pas processes, environments and (micro)organisms. Between production and eventual burial of organic molecules, however, large changes in composition and abundance of these molecules occur. Especially once organic molecules are deposited in the sediment, processes such as benthic activity and re-oxygenation in the surface sediment can affect their compositions. These processes may lead to significant differences between organic proxies as produced in the water column and as they are recorded in the sediment. In this Darwin subproject we plan to examine the impact of these processes on organic proxy records in close collaboration with benthic biologists and sedimentary biogeochemists at NIOO. We will study the impact of sedimentary biological activity on the degradation of organic molecules by analyzing sediments with a range of diagenetic states and of anoxically labelled biomass. Furthermore, we will analyse the in situ production of biomarker molecules by quantitatively comparing the abundance of phospholipids, derived from living cells, to that of core lipids, derived from both living and fossil cells. Finally, we will search for proxies of past benthic processes.

Publications
Lengger, S.K., Hopmans, E.C., Sinninghe Damsté, J.S., Schouten, S. (2012). Comparison of extraction and work up techniques for analysis of core and intact polar tetraether lipids from sedimentary environments. Organic Geochemistry47: 34-40.
Darwin Center authors: Hopmans E. C., Lengger S., Schouten S., Sinninghe Damsté J. S.

Lengger, S.K., Hopmans, E.C., Reichart, G.-J., Sinninghe Damsté, J.S., Schouten, S. (2012). Intact polar and core glycerol dibiphytanyl glycerol tetraether lipids in the Arabian Sea Water Oxygen Minimum Zone: II. Selective preservation and degradation in sediments and consequences for the TEX86.. Geochimica.et Cosmochimica Acta98: 244-258.
Darwin Center authors: Hopmans E. C., Lengger S., Reichart G. J., Schouten S., Sinninghe Damsté J. S.

S. K. Lengger (2013). Production and preservation of archaeal glycerol dibiphytanyl glycerol tetraethers as intact polar lipids in marine sediments: Implications for their use in microbial ecology and TEX86 paleothermometry.
Darwin Center authors: Lengger S.

Lengger, S.K. Hopmans, E.C. Sinninghe Damsté, J.S. Schouten, S (2014). Fossilization and degradation of archaeal intact polar tetraether lipids in deeply buried marine sediments ( Peru Margin). Geobiology12: 212-220.
Darwin Center authors: Hopmans E. C., Lengger S., Schouten S., Sinninghe Damsté J. S.

Lengger, S.K. Hopmans, E.C. Sinninghe Damsté, J.S. LneSchouten, S (2014). Impact of sedimentary degradation and deep water column production on GDGT abundance and distribution in surface sediments in the Arabian Sea: Implications for the TEX86 paleothermometer. Geochimica et Cosmochimica Acta142: 386-399.
Darwin Center authors: Hopmans E. C., Lengger S., Schouten S., Sinninghe Damsté J. S.

Lengger, S.K., Lipsewers, Y.A., de Haas, H., Sinninghe Damsté, J.S., Schouten, S. (2014). Lack of 13C-label incorporation suggests low turnover rates of thaumarchaeal intact polar tetraether lipids in sediments from the Iceland shelf. Biogeosciences11(2): 201-216.
Darwin Center authors: Lengger S., Lipsewers A., Schouten S., Sinninghe Damsté J. S.