Origins of archaeal tetraether lipids in sediments : insights from radiocarbon analysis
Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 72 (2008): 4577-4594, doi:10.1016/j.gca.2008.06.021...
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/2486 2023-05-15T18:01:03+02:00 Origins of archaeal tetraether lipids in sediments : insights from radiocarbon analysis Shah, Sunita R. Mollenhauer, Gesine Ohkouchi, Naohiko Eglinton, Timothy I. Pearson, Ann 2008-06-20 application/pdf https://hdl.handle.net/1912/2486 en_US eng https://doi.org/10.1016/j.gca.2008.06.021 https://hdl.handle.net/1912/2486 Preprint 2008 ftwhoas https://doi.org/10.1016/j.gca.2008.06.021 2022-05-28T22:57:37Z Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 72 (2008): 4577-4594, doi:10.1016/j.gca.2008.06.021. Understanding the supply and preservation of glycerol dibiphytanyl glycerol tetraethers (GDGTs) in marine sediments helps inform their use in paleoceanography. Compound-specific radiocarbon measurements of sedimentary alkenones from multiple environments have been used to gain insight into processes that affect paleo-temperature reconstructions. Similar analyses are warranted to investigate how analogous processes affecting GDGTs impact TEX86 paleotemperatures. Here we present radiocarbon measurements on individual GDGTs from Bermuda Rise and Santa Monica Basin sediments and discuss the results in the context of previous studies of co-depositional alkenones and foraminifera. The 149 C contents of GDGTs and planktonic foraminifera in Bermuda Rise are very similar, suggesting a local source; and TEX86- derived temperatures agree more closely with foraminiferal temperatures than do temperatures. In contrast, GDGTs in Santa Monica Basin are depleted in 1412 C relative to both alkenones and foraminifera, and TEX86 temperatures agree poorly with known surface water values. We propose three possible factors that could explain these results: (i) GDGTs may be labile relative to alkenones during advective transport through oxic waters; (ii) archaeal production deep in the water column may contribute 1416 C-depleted GDGTs to sediments; and (iii) some GDGTs also may derive from sedimentary archaeal communities. Each of these three processes is likely to occur with varying relative importance depending on geographic location. The latter two may help to explain why TEX86 temperature reconstructions from Santa Monica Basin do not appear to reflect actual sea surface temperatures. Terrigenous GDGTs are unlikely to be major ... Report Planktonic foraminifera Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Geochimica et Cosmochimica Acta 72 18 4577 4594 |
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Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
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ftwhoas |
language |
English |
description |
Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 72 (2008): 4577-4594, doi:10.1016/j.gca.2008.06.021. Understanding the supply and preservation of glycerol dibiphytanyl glycerol tetraethers (GDGTs) in marine sediments helps inform their use in paleoceanography. Compound-specific radiocarbon measurements of sedimentary alkenones from multiple environments have been used to gain insight into processes that affect paleo-temperature reconstructions. Similar analyses are warranted to investigate how analogous processes affecting GDGTs impact TEX86 paleotemperatures. Here we present radiocarbon measurements on individual GDGTs from Bermuda Rise and Santa Monica Basin sediments and discuss the results in the context of previous studies of co-depositional alkenones and foraminifera. The 149 C contents of GDGTs and planktonic foraminifera in Bermuda Rise are very similar, suggesting a local source; and TEX86- derived temperatures agree more closely with foraminiferal temperatures than do temperatures. In contrast, GDGTs in Santa Monica Basin are depleted in 1412 C relative to both alkenones and foraminifera, and TEX86 temperatures agree poorly with known surface water values. We propose three possible factors that could explain these results: (i) GDGTs may be labile relative to alkenones during advective transport through oxic waters; (ii) archaeal production deep in the water column may contribute 1416 C-depleted GDGTs to sediments; and (iii) some GDGTs also may derive from sedimentary archaeal communities. Each of these three processes is likely to occur with varying relative importance depending on geographic location. The latter two may help to explain why TEX86 temperature reconstructions from Santa Monica Basin do not appear to reflect actual sea surface temperatures. Terrigenous GDGTs are unlikely to be major ... |
format |
Report |
author |
Shah, Sunita R. Mollenhauer, Gesine Ohkouchi, Naohiko Eglinton, Timothy I. Pearson, Ann |
spellingShingle |
Shah, Sunita R. Mollenhauer, Gesine Ohkouchi, Naohiko Eglinton, Timothy I. Pearson, Ann Origins of archaeal tetraether lipids in sediments : insights from radiocarbon analysis |
author_facet |
Shah, Sunita R. Mollenhauer, Gesine Ohkouchi, Naohiko Eglinton, Timothy I. Pearson, Ann |
author_sort |
Shah, Sunita R. |
title |
Origins of archaeal tetraether lipids in sediments : insights from radiocarbon analysis |
title_short |
Origins of archaeal tetraether lipids in sediments : insights from radiocarbon analysis |
title_full |
Origins of archaeal tetraether lipids in sediments : insights from radiocarbon analysis |
title_fullStr |
Origins of archaeal tetraether lipids in sediments : insights from radiocarbon analysis |
title_full_unstemmed |
Origins of archaeal tetraether lipids in sediments : insights from radiocarbon analysis |
title_sort |
origins of archaeal tetraether lipids in sediments : insights from radiocarbon analysis |
publishDate |
2008 |
url |
https://hdl.handle.net/1912/2486 |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_relation |
https://doi.org/10.1016/j.gca.2008.06.021 https://hdl.handle.net/1912/2486 |
op_doi |
https://doi.org/10.1016/j.gca.2008.06.021 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
72 |
container_issue |
18 |
container_start_page |
4577 |
op_container_end_page |
4594 |
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1766170383251144704 |