Stable isotope composition of the carbonate concretion in loess and climate change

Abstract Carbonate concretions are commonly found in the loess in China. Oxygen and carbon isotopic compositions of carbonate concretions collected from 14 different paleosols (S 1 –S 14 ) in the Lishi Formation of Luochuan loess section, China were analysed. The isotopic compositions of concretion in loess are useful tools in paleoclimatic study. Usually the more developed the paleosol is, the less negative the δ 18 O values and the more negative the δ 13 C values are. The oxygen isotopic composition of these paleosols varies within a range of about 1.3‰. The carbon isotopic composition, however, shows larger variations from one paleosol to the other, within a range of 5.3‰. An attempt was made to semi-quantitatively estimate the paleosol formation temperature and precipitation based on the carbon and oxygen isotopic data obtained.