In:
Quaternary Research, Cambridge University Press (CUP), Vol. 63, No. 1 ( 2005-01), p. 15-30
Abstract:
13 C/ 12 C and 18 O/ 16 O ratios of aragonite shells of modern land snails from the southern Great Plains of North America were measured for samples from twelve localities in a narrow east–west corridor that extended from the Flint Hills in North Central Oklahoma to the foothills of the Sangre de Cristo Mountains in Northern New Mexico, USA. Across the study area, shell δ 18 O values (PDB scale) ranged from −4.1‰ to 1.2‰, while δ 13 C values ranged from −13.2‰ to 0.0‰. δ 18 O values of the shell aragonite were predicted with a published, steady state, evaporative flux balance model. The predicted values differed (with one exception) by less than 1‰ from locality averages of measured δ 18 O values. This similarity suggests that relative humidity at the time of snail activity is an important control on the δ 18 O values of the aragonite and emphasizes the seasonal nature of the climatic information preserved in the shells. Correlated δ 13 C values of coexisting Vallonia and Gastrocopta suggest similar feeding habits and imply that these genera can provide information on variations in southern Great Plains plant ecology. Although there is considerable scatter, multispecies, transect average δ 13 C values of the modern aragonite shells are related to variations in the type of photosynthesis (i.e., C 3 , C 4 ) in the local plant communities. The results of this study emphasize the desirability of obtaining isotope ratios representing averages of many shells in a locale to reduce possible biases associated with local variations among individuals, species, etc., and thus better represent the “neighborhood” scale temporal and/or spatial environmental variations of interest in studies of modern and ancient systems.
Type of Medium:
Online Resource
ISSN:
0033-5894
,
1096-0287
DOI:
10.1016/j.yqres.2004.09.009
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
2005
detail.hit.zdb_id:
1471589-2
detail.hit.zdb_id:
205711-6
SSG:
13
SSG:
14
