The coastal desert of northern Mauritania with sparse vegetation

Most of the sparse vegetation in the desert protect their leaves with a fatty substance to prevent desiccation: plant waxes. These waxes are eroded off the plants by dust and can be found back in ocean sediments.

Biomarkers in marine sedimentary archives are much used to reconstruct continental palaeoclimatic and palaeohydrological conditions. However, never before were they analysed in modern sediments from sediment traps or sea-floor sediments from the open ocean. The latest paper by Laura Schreuder has done just that and sheds new light on the applicability of these proxies in modern and fossil sediments.

The latitudinal variation in concentration and distribution of these biomarkers in marine sediments relatively close to the continent has been widely studied, but little is known on the extent to which this continental signal extends to the ocean. Furthermore, no studies have examined the seasonal variation in the deposition of these biomarkers in marine sediments.

The paper presents longitudinal variation in the composition of long chain n-alkanes and two other terrestrial higher plant biomarkers (long chain n-alkanols and long chain fatty acids) in atmospheric particles, as well as longitudinal and seasonal variation in long chain n-alkanes in sinking particles in the ocean at different water depths and in surface sediments, all collected along a 12oN transect across the tropical North Atlantic Ocean.

Full reference: Laura T. Schreuder, Jan-Berend W. Stuut, Laura F. Korte, Jaap S. Sinninghe Damsté, Stefan Schouten (2017)  Aeolian transport and deposition of plant wax n-alkanes across the tropical North Atlantic Ocean. Organic Geochemistry 115, 113-123

Read the paper at: