TEX86 2527340 220096069 2008-06-18T07:18:57Z William M. Connolley 8072 Reverted edits by [[Special:Contributions/Gregz08|Gregz08]] ([[User talk:Gregz08|talk]]) to last version by Smith609 {{downsize|title=TEX<sub>86</sub>}} '''TEX<sub>86</sub>''' is a [[paleothermometer]] based on the composition of membrane [[lipid]]s of the marine [[plankton|picoplankton]] [[Crenarchaeota]]. Wuchter et al. (2004) found that the number of cyclopentane rings in Crenarchaeota membrane lipids changes linearly with temperature in order to regulate membrane fluidity. The sedimentary composition of such lipids - which exist as far back as the early [[Cretaceous]] - can therefore be used to reconstruct average temperatures experienced by the plankton, and thus of the past water column. This method was used by Jenkyns et al. (2004) to show that average sea surface temperatures in the [[Arctic Ocean]] (80 degrees N) were as high as 15 degrees Celsius in the late [[Cretaceous]], compared to -15 degrees Celsius today. ==References== *Schouten, S., Hopmans, E.C., Schefus, E., and Sinninghe Damste, 2002, Distributional variation in marine crenarchaeotal membrane lipids: a new tool for reconstructing ancient sea water temperatures?: Earth and Planetary Science Letters, v. 204, p. 265-274. *Wuchter, C., Schouten, S., Coolen, M., Damste, J. (2004) Temperature-dependent variation in the distribution of tetraether membrane lipids of marine Crenarchaeota: Implications for TEX86 paleothermometry. ''PALEOCEANOGRAPHY'' '''19''': PA4028 *Jenkyns, H., Forster, A., Schouten, S., Damste, J (2004) High temperatures in the Late Cretaceous Arctic Ocean. ''Nature'' '''432''': 888-891. [[Category:Paleoclimatology]]