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

Abstract

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., δ13Cshell and δ18Oshell) 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 δ13Cshell and δ18Oshell 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 δ13Cshell can record local vegetation information and has the potential to be a reliable precipitation proxy. Interestingly, δ18Oshell 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 δ18O (δ18Op), these phenomena may support the dominant control of δ18Op on δ18Oshell.