Paleoclimatic implications of the spatial patterns of modern and LGM European land-snail shell δ 18 O

• Published in: Quaternary Research
• Main Authors: Kehrwald, Natalie M., McCoy, William D., Thibeault, Jeanne, Burns, Stephen J., Oches, Eric A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2010
• Subjects: Sea ice
• Online Access: http://dx.doi.org/10.1016/j.yqres.2010.03.001; http://api.elsevier.com/content/article/PII:S0033589410000190?httpAccept=text/xml; http://api.elsevier.com/content/article/PII:S0033589410000190?httpAccept=text/plain; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400010024

Abstract The oxygen isotopic composition of land-snail shells may provide insight into the source region and trajectory of precipitation. Last glacial maximum (LGM) gastropod shells were sampled from loess from Belgium to Serbia and modern land-snail shells both record δ 18 O values between 0‰ and − 5‰. There are significant differences in mean fossil shell δ 18 O between sites but not among genera at a single location. Therefore, we group δ 18 O values from different genera together to map the spatial distribution of δ 18 O in shell carbonate. Shell δ 18 O values reflect the spatial variation in the isotopic composition of precipitation and incorporate the snails' preferential sampling of precipitation during the warm season. Modern shell δ 18 O decreases in Europe along a N–S gradient from the North Sea inland toward the Alps. Modern observed data of isotopes in precipitation (GNIP) demonstrate a similar trend for low-altitude sites. LGM shell δ 18 O data show a different gradient with δ 18 O declining toward the ENE, implying a mid-Atlantic source due to increased sea ice and a possible southern displacement of the westerly jet stream. Balkan LGM samples show the influence of a Mediterranean source, with δ 18 O values decreasing northward.