Distribution of intact and core tetraether lipids in water column profiles of suspended particulate matter off Cape Blanc, NW Africa

摘要: Abstract In the reconstruction of sea surface temperature (SST) from sedimentary archives, secondary sources, lateral transport and selective preservation are considered to be mainly negligible in terms influencing primary signal. This is also true for archaeal glycerol dialkyl tetraethers (GDGTs) that form basis TEX86 SST proxy. Our samples represent four years variability on a transect off Cape Blanc (NW Africa). We studied subsurface production, vertical intact polar lipids core GDGTs water column at high resolution suspended particulate matter (SPM) photic zone, oxygen minimum zone (OMZ), nepheloid layers (NL) between these. Furthermore we compared SPM GDGT composition with underlying sediments. first study reports values precursor (IPLs) associated specific head groups (IPL-specific TEX86). show clear deviation OMZ 300 600 m. Since neither nor degradation provides satisfactory explanation observed TEX-derived profiles, bias towards higher temperatures both core- IPL-specific values, suggest situ production archaea distinct relationship lipid biosynthesis responsible mechanism. However, NW-African upwelling system contribution sediments did not seem affect as it showed no still reflected signal waters 0 60 m.