Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.589512
Title: Linking plant macrofossil, testate amoebae and geochemical element data from oceanic bogs in the British Isles to detect palaeoclimate change
Author: Küttner, Anke
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 2013
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Abstract:
Bogs are sensitive palaeoclimate archives as they rely solely on atmospheric deposition for water and nutrients. A range of biological mire surface wetness proxies have been explored in previous studies, but linking geochemical elements to particular plant macrofossils and a quantitative water table depth reconstruction has not been attempted. The thesis aims to combine biological and geochemical data to evaluate the potential of these proxies when combined and to test the applicability of halogens as a palaeoclimate proxy. To do so, records of plant macrofossils, testate amoebae and geochemistry were reconstructed then ordinated from three bogs (Tyndrain, Wales; Raeburn Flow, Scotland; Annaholty, Ireland) along the western seaboard of the North Atlantic. Additionally, lead enrichment (Pb EF) and the pattern of lithogenic elements were measured to infer phases of anthropogenic activity. A testate amoebae based transfer function, used to identify water table changes, suggests regional climatic variability with only the ‘2650 BP wet shift' identifiable at all three sites. RBF and ANN show several shifts between wetter and drier conditions which appear to be in antiphase. In contrast, at TYN only drier phases were recorded during the Dark Ages and the Little Ice Age. No direct link between the halogens and mire surface wetness based on the testate amoebae was detectable. Factor analyses by principal components run on the halogens combined with Sphagnum mosses, monocots, unidentified organic matter, lithogenic elements and mire surface wetness to identify underlying factors driving their distribution, suggest inter-­‐site variability. It was not possible to identify a principal sink in terms of a specific moss species with any certainty, although a negative correlation with Sphagnum Section Acutifolia (dry indicator species) was found at ANN. Iodine appears to be more closely associated with the lithogenic elements, while bromine has similarities with both iodine and chlorine. iv The Pb EF results for Raeburn Flow and Annaholty are in agreement with patterns for historical global Pb production (i.e. Roman, Medieval and Industrial period enrichments are identifiable) and evidence for changes in land use. This limits the potential of lithogenic elements as palaeoclimatic indicators. Overall, the halogen pattern is inconclusive and requires further study, although for Annaholty a link between wetter conditions and an increase in halogens can be demonstrated.
Supervisor: Not available Sponsor: University of Aberdeen ; Quaternary Research Association (Great Britain)
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.589512  DOI: Not available
Keywords: Paleoclimatology (Great Britain) ; Bogs
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