A Clumped-Isotope Study of Modern and Last Glacial Terrestrial Gastropod Shells
Abstract
Terrestrial gastropods (land snails) have been used to investigate paleoclimate and paleoecosystems. One of the more widely used tools is based on the δ18O of their aragonitic shells. However, traditional shell δ18O values are often difficult to interpret because several factors including temperature, relative humidity, water vapor δ18O, and liquid water δ18O imbibed by the snail, all affect the snail oxygen isotope budget. The advent of clumped isotopes offer an opportunity to calculate snail growth temperature and body water δ18O values that increase the accuracy of paleoenvironmental inferences using land snails.
Using clumped isotopes, we are analyzing snail shells from four regions spanning a range of latitudes and climatic regimes: the Chinese Loess Plateau; Central Europe; the southern Mississippi River Valley; and the island Lanzarote in the Canary Islands. The snails sampled were either modern or from the Last Glacial Maximum (LGM; approximately 23 - 18 kya). Additionally, by coupling modern snail data with temperature data from local weather stations and hydrologic data from the Global Network of Isotopes in Precipitation, we are investigating whether the oxygen isotope values of snail shells represents a seasonal or annual signal at different latitudes. Results to date indicate that clumped isotopes offer a new opportunity to not only provide reliable paleoclimate data from fossil shells, but also help us to understand snail growth patterns and ecology of taxa. Ultimately such measurements can aid us in developing tools to better understanding dynamics of microclimates in response to climate change, as well as strengthen our ability to use snail shells in paleoenvironmental studies.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMPP13F1385B
- Keywords:
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- 4901 Abrupt/rapid climate change;
- PALEOCEANOGRAPHYDE: 4926 Glacial;
- PALEOCEANOGRAPHYDE: 4928 Global climate models;
- PALEOCEANOGRAPHYDE: 4999 General or miscellaneous;
- PALEOCEANOGRAPHY