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Titel |
Isotope hydrology of dripwaters in a Scottish cave and implications for stalagmite palaeoclimate research |
VerfasserIn |
L. Fuller, A. Baker, I. J. Fairchild, Christoph Spötl, A. Marca-Bell, P. Rowe, P. F. Dennis |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 12, no. 4 ; Nr. 12, no. 4 (2008-08-05), S.1065-1074 |
Datensatznummer |
250010758
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Publikation (Nr.) |
copernicus.org/hess-12-1065-2008.pdf |
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Zusammenfassung |
Dripwater hydrology and hydrogeochemistry is particularly useful in
constraining the meaning of speleothem palaeoclimate archives, for example
using δ18O signatures. Here, we calibrate the relationship between
δ18O in precipitation, percolation waters and contemporary calcite
deposits, at Tartair cave, Sutherland, NW Scotland, an Atlantic site
sensitive to regional changes both of temperature and precipitation. Monthly
precipitation displayed a 7.1‰ range in δ18O, a negative
linear relationship with rainfall amount, and no correlation with
temperature. Autogenically-derived cave percolation waters show little
variation in δ18O during the same period and their annual weighted
mean is the same as that of the local precipitation. This evidence together
with hydrological data and electroconductivity values indicates that
percolation waters are well mixed and dominated by stored water. Calculated
values of δ18O of calcite deposited in this cave environment
indicate that the cave deposits are forming close to isotopic equilibrium and
kinetic effects are negligible. Comparison of a high-resolution
δ18O stalagmite record with the instrumental record of climate
indicates that isotopically heavy values are reflective of relatively cold,
dry conditions (and vice-versa for warm, wet condition) and hence that
stalagmite oxygen isotopes provide an appropriate means of investigating the
palaeoclimate in this location. |
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