Climatic significance of modern minute land snail shells δ13C and δ18O on the Chinese Loess Plateau

Land snails are abundant and well preserved in loess-paleosol sequences on the Chinese Loess Plateau (CLP) and are often regarded as valuable climatic indicators in paleoclimate reconstruction. To date, many stable isotope investigations have been carried out on land snail shells (e.g., delta(13)Cshell and delta(18)Oshell) from diverse geographical and climatic regions. However, few studies have been conducted on modern minute land snails (2-10 mm) on the CLP, and their climatic significance has not been adequately understood. Here, we present new delta(13)Cshell and delta(18)Oshell data from four minute modern land snails (Pupilla aeoli, Gastrocopta armigerella, Opeas striatissimum, Vallonia tenera), and analyses of their correlations with climatic factors (growing season temperature, precipitation and relative humidity) were conducted to examine their climatic significance across the CLP. The results show that delta(13)Cshell can record local vegetation information and has the potential to be a reliable precipitation proxy. Interestingly, delta(18)Oshell exhibits spatially scattered values in the studied region, and these data yielded poor correlations with various climatic parameters, such as precipitation amount, temperature and relative humidity. Given the similar spatial characteristics of observed precipitation delta O-18 (delta(18)Op), these phenomena may support the dominant control of delta(18)Op on delta(18)Oshell.

Automated summary

Land snails on the Chinese Loess Plateau are valuable climatic indicators in paleoclimate reconstruction. This study focuses on small modern land snails and their climatic significance. The results show that δ（13）Cshell can be a reliable precipitation proxy, while δ（18）Oshell exhibits poor correlations with various climatic parameters.