alkenones

alkenones

[′al·kə‚nōnz]
(geology)
Long-chain (37-39 carbon atoms) di-, tri-, and tetraunsaturated methyl and ethyl ketones produced by certain phytoplankton (coccolithophorids), which biosynthetically control the degree of unsaturation (number of carbon-carbon double bonds) in response to the water temperature; the survival of this temperature signal in marine sediment sequences provides a temporal record of sea surface temperatures that reflect past climates.
References in periodicals archive ?
To reconstruct the salinity, the WHOI team analyzed sediments containing highly resistant organic compounds called alkenones, which are uniquely produced by Emiliania huxleyi-the same photosynthetic organism oceanographers study to determine past sea surface temperatures.
Researchers analysed marine sediment collected by drilling and measured alkenones - organic compounds produced by phytoplankton.
Many papers discus the controlling mechanisms that may have forced major climate change, such as geographical and oceanographic changes during the Late Ordovician or changing ocean gateways in the Cenozoic, while others discuss biological and chemical proxies that can be used to track ancient climate change, such as the use of Ca/Mg ratio of foraminifer tests or alkenones from surface- dwelling marine-algae.