Stable isotopes from diatom silica

Leng, Melanie J.; Swann, George E. A.

doi:10.1017/cbo9780511763175.035

Cited by 7 publications

(8 citation statements)

References 125 publications

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“…Therefore, some of the diatom d 18 O composition is acquired soon after the formation of biogenic silica, during early diagenesis in the water column and later during early sediment burial (Dodd and Sharp 2010). Interestingly, the conflating effects of (Leng and Swann 2010). These methods are more popular in palaeoceanography with few published studies in (palaeo)limnology (Webb et al 2016).…”

Section: The Hydrous Layer and Maturation Of Oxygen Isotopes In Biogementioning

confidence: 99%

The stable isotope composition of organic and inorganic fossils in lake sediment records: Current understanding, challenges, and future directions

Hardenbroek

Chakraborty²,

Davies

et al. 2018

Quaternary Science Reviews

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This paper provides an overview of stable isotope analysis (H, C, N, O, Si) of the macroand microscopic remains from aquatic organisms found in lake sediment records and their application in (palaeo)environmental science. Aquatic organisms, including diatoms, macrophytes, invertebrates, and fish, can produce sufficiently robust remains that preserve well as fossils and can be identified in lake sediment records. Stable isotope analyses of these remains can then provide valuable insights into habitat-specific biogeochemistry, feeding ecology, but also on climatic and hydrological changes in and around lakes. Since these analyses focus on the remains of known and identified organisms, they can provide more specific and detailed information on past ecosystem, food web and environmental changes affecting different compartments of lake ecosystems than analyses on bulk sedimentary organic matter or carbonate samples. We review applications of these types of analyses in palaeoclimatology, palaeohydrology, and palaeoecology. Interpretation of the environmental 'signal' provided by taxon-specific stable isotope analysis requires a thorough understanding of the ecology and phenology of the organism groups involved. Growth, metabolism, diet, feeding strategy, migration, taphonomy and several other processes can lead to isotope fractionation or otherwise influence the stable isotope signatures of the remains from aquatic organisms. This paper includes a review of the (modern) calibration, culturing and modeling studies used to quantify the extent to which these factors influence stable isotope values and provides an outlook for future research and methodological developments for the different examined fossil groups.

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Section: The Hydrous Layer and Maturation Of Oxygen Isotopes In Biogementioning

confidence: 99%

The stable isotope composition of organic and inorganic fossils in lake sediment records: Current understanding, challenges, and future directions

Hardenbroek

Chakraborty²,

Davies

et al. 2018

Quaternary Science Reviews

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“…Their siliceous frustules can be preserved over long timescales and are generally identifiable to the species level, enabling the reconstruction of past environments well beyond the instrumental record. The silica frustule comprises two layers: a tetrahedrally bonded silica layer (–Si–O–Si) which incorporates oxygen from the surrounding water during formation, and an outer hydrous layer (–Si–OH) which continues to exchange oxygen with the surrounding water following frustule formation (Leng and Swann, ). By isolating and extracting oxygen from the internal silica, the isotopic composition of the diatom (δ 18 O diatom ) can be determined and used to reconstruct past changes in climate (Leng and Barker, ).…”

Section: Introductionmentioning

confidence: 99%

The effect of species on lacustrine δ¹⁸ O_diatom and its implications for palaeoenvironmental reconstructions

et al. 2014

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The oxygen isotope composition of diatom silica (d 18 O diatom ) is increasingly being used to reconstruct climate from marine and lacustrine sedimentary archives. Although diatoms are assumed to precipitate their frustule in isotopic equilibrium with their surrounding water, it is unclear whether internal processes of a given species affect the fractionation of oxygen between the water and the diatom. We present d 18 O diatom data from two diatom size fractions (3-38 and >38 mm) characterized by different species in a sediment core from Heart Lake, Alaska. Differences in d 18 O diatom between the two size fractions varies from 0 to 1.2‰, with a mean offset of 0.01‰ (n ¼ 20). Fourier transform infrared spectroscopy confirms our samples consist of pure biogenic silica (SiO 2 ) and d 18 O diatom trends are not driven by contamination. The maximum offset is outside the range of error, but the mean is within analytical error of the technique (AE 1.06‰), demonstrating no discernible speciesdependent fractionation in d 18 O diatom . We conclude that lacustrine d 18 O diatom measurements offer a reliable and valuable method for reconstructing d 18 O water . Considering the presence of small offsets in our two records, we advise interpreting shifts in d 18 O diatom only where the magnitude of change is greater than the combined analytical error.

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“…As an open lake, and with no evidence of species effects or dissolution on the remodelled ẟ 18 O diatom record, it is expected that Baunt's ẟ 18 O diatom record will reflect changes in temperature and palaeohydrology, linked to ẟ 18 O precipitation values (Leng and Barker, 2006;Leng and Marshall, 2004;Leng and Swann, 2010). The Baunt ẟ 18 O diatom record has a range in values of 9.4‰, and if these were driven purely by changes in the lake water temperature, it indicates temperature changes through this period that appear unrealistic.…”

Section: Integrity Of and Controls On The New Lake Baunt ẟ 18 O Diatomentioning

confidence: 99%

“…4, 6, 7 and 8). Several factors may explain this, including the seasonality of the diatom record, as the isotopic signal is recorded during the growing season (Leng and Swann, 2010), with bulk samples tending to be averaged across the spring to the autumn. This indicates that the diatoms will be recording the springautumn conditions.…”

Section: Ka Cal Bp)mentioning

confidence: 99%

Hydrological (in)stability in Southern Siberia during the Younger Dryas and early Holocene

Harding

Безрукова

Kostrova

et al. 2020

Global and Planetary Change

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Southern Siberia is currently undergoing rapid warming, inducing changes in vegetation, loss of permafrost, and impacts on the hydrodynamics of lakes and rivers. Lake sediments are key archives of environmental change and contain a record of ecosystem variability, as well as providing proxy indicators of wider environmental and climatic change. Investigating how hydrological systems have responded to past shifts in climate can provide essential context for better understanding future ecosystem changes in Siberia. Oxygen isotope ratios within lacustrine records provide fundamental information on past variability in hydrological systems. Here we present a new oxygen isotope record from diatom silica (ẟ 18 O diatom) at Lake Baunt (55 • 11 ′ 15 ′′ N, 113 • 01,45 ′′ E), in the southern part of eastern Siberia, and consider how the site has responded to climate changes between the Younger Dryas and Early to Mid Holocene (ca. 12.4 to 6.2 ka cal BP). Excursions in ẟ 18 O diatom are influenced by air temperature and the seasonality, quantity, and source of atmospheric precipitation. These variables are a function of the strength of the Siberian High, which controls temperature, the proportion and quantity of winter versus summer precipitation, and the relative dominance of Atlantic versus Pacific air masses. A regional comparison with other Siberian ẟ 18 O diatom records, from lakes Baikal and Kotokel, suggests that ẟ 18 O diatom variations in southern Siberia reflect increased continentality during the Younger Dryas, delayed Early Holocene warming in the region, and substantial climate instability between ~10.5 to ~8.2 ka cal BP. Unstable conditions during the Early Holocene thermal optimum most likely reflect localised changes from glacial melting. Taking the profiles from three very different lakes together, highlight the influence of site specific factors on the individual records, and how one site is not indicative of the region as a whole. Overall, the study documents how sensitive this important region is to both internal and external forcing.

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Stable isotopes from diatom silica

Cited by 7 publications

References 125 publications

The stable isotope composition of organic and inorganic fossils in lake sediment records: Current understanding, challenges, and future directions

The stable isotope composition of organic and inorganic fossils in lake sediment records: Current understanding, challenges, and future directions

The effect of species on lacustrine δ¹⁸ O_diatom and its implications for palaeoenvironmental reconstructions

Hydrological (in)stability in Southern Siberia during the Younger Dryas and early Holocene

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Stable isotopes from diatom silica

Cited by 7 publications

References 125 publications

The stable isotope composition of organic and inorganic fossils in lake sediment records: Current understanding, challenges, and future directions

The stable isotope composition of organic and inorganic fossils in lake sediment records: Current understanding, challenges, and future directions

The effect of species on lacustrine δ18 Odiatom and its implications for palaeoenvironmental reconstructions

Hydrological (in)stability in Southern Siberia during the Younger Dryas and early Holocene

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The effect of species on lacustrine δ¹⁸ O_diatom and its implications for palaeoenvironmental reconstructions