TEX-86
Encyclopedia
TEX86 is a paleothermometer
based on the composition of membrane lipid
s of the marine 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 currently ice covered Arctic Ocean
(80 degrees N) were as high as 15 degrees Celsius in the late Cretaceous
.
Paleothermometer
A paleothermometer is a methodology for determining past temperatures using a proxy found in a natural record such as a sediment, ice core, tree rings or TEX86.=...
based on the composition of membrane lipid
Lipid
Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...
s of the marine picoplankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
Crenarchaeota
Crenarchaeota
In taxonomy, the Crenarchaeota has been classified as either a phylum of the Archaea kingdom or a kingdom of its own...
.
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
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
- 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 currently ice covered Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
(80 degrees N) were as high as 15 degrees Celsius in the late Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
.