An offset in TEX values between interbedded lithologies: Implications for sea-surface temperature reconstructions
The TEX (TetraEther indeX of tetraethers consisting of 86 carbon atoms) sea-surface temperature (SST) proxy is based on the distribution of isoprenoid glycerol dialkyl glycerol tetraether (GDGT) membrane lipids of pelagic Thaumarchaeota that are preserved in marine sediments. It is a valuable tool f...
Main Authors: | , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2014
|
Subjects: | |
Online Access: | http://discovery.ucl.ac.uk/1427164/ |
id |
ftucl:oai:eprints.ucl.ac.uk.OAI2:1427164 |
---|---|
record_format |
openpolar |
spelling |
ftucl:oai:eprints.ucl.ac.uk.OAI2:1427164 2023-05-15T17:33:46+02:00 An offset in TEX values between interbedded lithologies: Implications for sea-surface temperature reconstructions Littler, K Robinson, SA Bown, PR 2014-04-01 http://discovery.ucl.ac.uk/1427164/ unknown Palaeogeography, Palaeoclimatology, Palaeoecology , 399 42 - 51. (2014) Article 2014 ftucl 2014-04-24T23:01:06Z The TEX (TetraEther indeX of tetraethers consisting of 86 carbon atoms) sea-surface temperature (SST) proxy is based on the distribution of isoprenoid glycerol dialkyl glycerol tetraether (GDGT) membrane lipids of pelagic Thaumarchaeota that are preserved in marine sediments. It is a valuable tool for reconstructing past SSTs from sedimentary archives; however there are still major uncertainties as to the effects of variables other than temperature on the proxy. Here we present the first study of GDGT variability across early Cretaceous interbedded pelagic and shelf-sourced turbiditic sediments from two Deep Sea Drilling Project (DSDP) sites in the western North Atlantic. The results indicate that a small, but consistent, offset in TEX ratios, equivalent to ~1-2°C of temperature difference, occurs between interbedded lithologies of a similar age. The offset can be attributed to spatial differences in sea-surface temperatures or thaumarchaeotal populations between the shelf and the open ocean, or to secondary diagenetic effects related to oxic degradation of the GDGTs. Of these, a difference in either thaumarchaeotal taxa or ecology between those living in the shelf and ocean areas seems most plausible. Regardless of the root cause of the offset, these findings highlight the necessity of careful sample selection prior to TEX analysis, to ensure robust interpretation of palaeotemperature trends. © 2014 Elsevier B.V. Article in Journal/Newspaper North Atlantic University College London: UCL Discovery |
institution |
Open Polar |
collection |
University College London: UCL Discovery |
op_collection_id |
ftucl |
language |
unknown |
description |
The TEX (TetraEther indeX of tetraethers consisting of 86 carbon atoms) sea-surface temperature (SST) proxy is based on the distribution of isoprenoid glycerol dialkyl glycerol tetraether (GDGT) membrane lipids of pelagic Thaumarchaeota that are preserved in marine sediments. It is a valuable tool for reconstructing past SSTs from sedimentary archives; however there are still major uncertainties as to the effects of variables other than temperature on the proxy. Here we present the first study of GDGT variability across early Cretaceous interbedded pelagic and shelf-sourced turbiditic sediments from two Deep Sea Drilling Project (DSDP) sites in the western North Atlantic. The results indicate that a small, but consistent, offset in TEX ratios, equivalent to ~1-2°C of temperature difference, occurs between interbedded lithologies of a similar age. The offset can be attributed to spatial differences in sea-surface temperatures or thaumarchaeotal populations between the shelf and the open ocean, or to secondary diagenetic effects related to oxic degradation of the GDGTs. Of these, a difference in either thaumarchaeotal taxa or ecology between those living in the shelf and ocean areas seems most plausible. Regardless of the root cause of the offset, these findings highlight the necessity of careful sample selection prior to TEX analysis, to ensure robust interpretation of palaeotemperature trends. © 2014 Elsevier B.V. |
format |
Article in Journal/Newspaper |
author |
Littler, K Robinson, SA Bown, PR |
spellingShingle |
Littler, K Robinson, SA Bown, PR An offset in TEX values between interbedded lithologies: Implications for sea-surface temperature reconstructions |
author_facet |
Littler, K Robinson, SA Bown, PR |
author_sort |
Littler, K |
title |
An offset in TEX values between interbedded lithologies: Implications for sea-surface temperature reconstructions |
title_short |
An offset in TEX values between interbedded lithologies: Implications for sea-surface temperature reconstructions |
title_full |
An offset in TEX values between interbedded lithologies: Implications for sea-surface temperature reconstructions |
title_fullStr |
An offset in TEX values between interbedded lithologies: Implications for sea-surface temperature reconstructions |
title_full_unstemmed |
An offset in TEX values between interbedded lithologies: Implications for sea-surface temperature reconstructions |
title_sort |
offset in tex values between interbedded lithologies: implications for sea-surface temperature reconstructions |
publishDate |
2014 |
url |
http://discovery.ucl.ac.uk/1427164/ |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Palaeogeography, Palaeoclimatology, Palaeoecology , 399 42 - 51. (2014) |
_version_ |
1766132376309596160 |