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| Titel |
Coupling δ18O values of rodent tooth and mollusc shell carbonates: a new approach to reconstructing Pleistocene palaeotemperatures? |
| VerfasserIn |
Elizabeth Peneycad, Ian Candy, Danielle Schreve |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250138645
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| Publikation (Nr.) |
 EGU/EGU2017-1736.pdf |
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| Zusammenfassung |
| The ratio of stable oxygen isotopes in fossil rodent teeth (δ18Ort) can potentially provide
valuable quantitative information about terrestrial palaeoclimate conditions. Grimes et al.
(2004) suggested that δ18Ort could be usefully combined with the δ18O values of coeval
biominerals, e.g. mollusc shells (δ18Oms), to estimate past summer temperatures during the
Quaternary period. Nevertheless, until now, the application of this approach to
Quaternary palaeoclimate reconstruction has remained unexplored. In addition, the
success of this approach is dependent upon the establishment of a statistically robust
relationship between δ18Ort and the δ18O of meteoric water (δ18Omw) in the modern
environment. However, such a relationship is yet to be quantified in relation to rodent tooth
carbonate.
Here, we present the preliminary results of 2 studies investigating the validity of δ18Ort as a
climate proxy. Firstly, isotope analyses were undertaken on modern vole (Microtus agrestis)
teeth from 3 locations across the UK. The results of these analyses reveal a significant
linear correlation between the mean δ18Ort and the mean δ18Omw. These findings
therefore demonstrate that a quantifiable relationship exists between δ18Ort and
δ18Omw, highlighting the potential of δ18Ort as an accurate recorder of local climatic
conditions.
This modern relationship was subsequently applied to the reconstruction of past δ18Omw
values for two Pleistocene interglacial sites in the UK. The δ18Omw values were calculated
using δ18Ort, and then combined with δ18Oms values derived from coeval fossil gastropod
assemblages in order to estimate mean summer palaeotemperatures. The results of these
calculations are in close agreement with multi-proxy temperature reconstructions derived
from the same deposits. This suggests that coupling the δ18O values of rodent tooth and
mollusc shell carbonates offers great potential as an approach to quantifying summer
palaeotemperatures in Europe, particularly for carbonate-rich sites at which alternative
temperature proxies may be unavailable.
References:
Grimes, S.T., Mattey, D.P., Collinson, M.E. & Hooker, J.J. (2004) Using mammal tooth
phosphate with freshwater carbonate and phosphate palaeoproxies to obtain mean
paleotemperatures. Quaternary Science Reviews, 23, pp.967–976. |
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