Molecular stratigraphy: a new tool for climatic assessment

Brassell, Simon C.; Eglinton, G.; Marlowe, I.T.; Pflaumann, Uwe; Sarnthein, Michael

doi:10.1038/320129a0

Cited by 1,050 publications

(582 citation statements)

References 27 publications

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“…Alkenones are a series of long-chain unsaturated organic compounds produced by a limited number of algae which could faithfully record environmental conditions where the algae live [31,36]. Over the past two decades, the U 3 k′ 7 proxy has been widely used to quantitatively reconstruct sea surface temperature changes on various timescales, and proved to be one of the best temperature proxies to date.…”

Section: Discussionmentioning

confidence: 99%

Solar influenced late Holocene temperature changes on the northern Tibetan Plateau

Liu

Zhao

et al. 2013

Chin. Sci. Bull.

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Considerable efforts have been made to extend temperature records beyond the instrumental period through proxy reconstructions, in order to further understand the mechanisms of past climate variability. Yet, the global coverage of existing temperature records is still limited, especially for some key regions like the Tibetan Plateau and for earlier times including the Medieval Warm Period (MWP). Here we present decadally-resolved, alkenone-based, temperature records from two lakes on the northern Tibetan Plateau. Characterized by marked temperature variability, our records provide evidence that temperatures during the MWP were slightly higher than the modern period in this region. Further, our temperature reconstructions, within age uncertainty, can be well correlated with solar irradiance changes, suggesting a possible link between solar forcing and natural climate variability, at least on the northern Tibetan Plateau.

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Section: Discussionmentioning

confidence: 99%

Solar influenced late Holocene temperature changes on the northern Tibetan Plateau

Liu

Zhao

et al. 2013

Chin. Sci. Bull.

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“…These compounds are synthesized by few species of microalgae belonging to the class of Haptophyceae [1][2][3][4]. Cultures of these species showed that the proportion of di-and triunsaturated alkenones changed linearly with water temperature [5,6]. This finding and the ubiquity of C 37 -C 39 alkenones in recent and past marine sediments has led to the widespread use of the C 37 homologs for the estimation of sea surface temperatures in climate change studies [7][8][9][10].…”

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confidence: 99%

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C₃₇-C₄₀ alkenones by GC-MS

López

Grimalt

2004

J. Am. Soc. Mass Spectrom.

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A method for the identification of double bond locations in polyunsaturated long chain alkenones adapted to nanogram amounts as currently analyzed by gas chromatography coupled to mass spectrometry (GC-MS) has been developed. The method is based on interpretation of the electron impact mass spectra of the imino derivatives of the carbonyl groups using either cyclopentyl or phenyl substitutents. Other complementary derivatization methods such as elaidization and hydrogenation have also been used for structural characterization of these compounds. This application has led to the identification of a novel homologous series of di-, tri-, and tetraunsaturated ketones with carbon number chain lengths between 37 and 40 in coastal hypersaline sediments. The novel series identified shows a distribution in which the double bond position between different homologs is established by reference to the distance from the carbonyl group whereas the previously known alkenones were constituted by unsaturated homologs with double bonds located at defined distances of the terminal methyl. This difference points out to a dissimilar, but still unknown, biogenic precursor of these novel alkenones. (J Am Soc Mass Spectrom 2004, 15, 1161-1172

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“…3a) is typical for haptophytes that produce carbonate skeletons, such as E. huxleyi or G. oceanica (Volkman et al, 1980;Conte et al, 1995). The low abundance of alkenones with more than two double bonds is also consistent with the relatively high temperature of these subtropical waters (Brassell et al, 1986). Although in coastal areas alkenones can also be produced by non-calcifying or ''naked'' haptophyte species like Isochrysis spp.…”

Section: Discussionmentioning

confidence: 93%

“…Alkenones are well established as an important group of lipids for paleoclimate reconstruction, as past surface water temperatures are recorded in their degree of unsaturation (Brassell et al, 1986;Prahl and Wakeham, 1987;Müller et al, 1998). The stable hydrogen and carbon isotopic compositions of these compounds have also been linked to past surface ocean salinity (Schouten et al, 2006;Schwab and Sachs, 2011) and pCO 2 conditions (Bidigare et al, 1997;Pagani et al, 2002), respectively.…”

Section: Introductionmentioning

confidence: 99%

Unusual C35 to C38 alkenones in mid-Holocene sediments from a restricted estuary (Charlotte Harbor, Florida)

Soelen

Lammers

Eglinton

et al. 2014

Organic Geochemistry

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Unusual C 35 to C 38 alkenones were identified in mid-Holocene (8-3.5 kyr BP) sediments from a restricted estuary in southwest Florida (Charlotte Harbor). The distribution was dominated by a C 36 diunsaturated (ω15,20) ethyl ketone, identical to the one present in Black Sea Unit 2 sediments. Other unusual alkenones were tentatively assigned as a C 35:2 (ω 15,20) methyl ketone, a C 37:2 (ω 17,22) methyl ketone and a C 38:2 (ω 17,22) ethyl ketone. In late Holocene sediments < 3.5 kyr BP, the common C 37 to C 39 alkenones were found. Compound-specific 14 C, 13 C, and D isotope measurements were used to constrain the possible origin of the alkenones. Conventional radiocarbon ages of alkenones and higher plant-derived long chain n-alcohols indicated no significant difference in age between mid-Holocene alkenones and higher plant n-alcohols. Both alcohols and alkenones were offset vs. calibrated ages of shell fragments in the same sediment core, which suggests they were pre-aged by 500-800 yr, implying resuspension and redistribution of the fine-grained sedimentary particles with which they are associated. The hydrogen isotopic (δD) composition (-190‰ to -200‰) of the C 37 and C 38 alkenones in the late Holocene sediments is in line with values for coastal haptophytes in brackish water. However, the unusual C 36 and C 38 alkenones from the mid Holocene sediments were enriched in D (by ca. 100‰) vs. the late Holocene alkenones. Also, δ 13 C values of mid-Holocene alkenones were consistently offset compared with late Holocene alkenones (-21‰ to -22‰ and -22‰ to -23‰, respectively). We suggest that the alkenones in Charlotte Harbor were produced by unknown alkenone-producing haptophyte.

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Molecular stratigraphy: a new tool for climatic assessment

Cited by 1,050 publications

References 27 publications

Solar influenced late Holocene temperature changes on the northern Tibetan Plateau

Solar influenced late Holocene temperature changes on the northern Tibetan Plateau

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C₃₇-C₄₀ alkenones by GC-MS

Unusual C35 to C38 alkenones in mid-Holocene sediments from a restricted estuary (Charlotte Harbor, Florida)

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Molecular stratigraphy: a new tool for climatic assessment

Cited by 1,050 publications

References 27 publications

Solar influenced late Holocene temperature changes on the northern Tibetan Plateau

Solar influenced late Holocene temperature changes on the northern Tibetan Plateau

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C37-C40 alkenones by GC-MS

Unusual C35 to C38 alkenones in mid-Holocene sediments from a restricted estuary (Charlotte Harbor, Florida)

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Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C₃₇-C₄₀ alkenones by GC-MS