The effect of maturity and depositional redox conditions on archaeal tetraether lipid palaeothermometry

Abstract

Recently we proposed a new organic sea surface temperature proxy, TEX86, based on the distribution of archaeal tetraether lipids. Here, we have examined the effect of oxic degradation and maturity on this new temperature proxy. Our results show that oxic degradation does not appear to affect the TEX86 values within the analytical error. Hydrous pyrolysis experiments suggest that thermal maturity does have an effect on TEX86. Sediments with relatively high amounts of 22S-hopanes [22S/(22S+22R) ratios > 0.1] or 17,21(H)-hopanes [/(++) ratios <0.5] may have TEX86 values which are biased towards lower values and, thus, lower sea surface temperatures.