Variations in CaCO_3 content and Sr isotopic composition of loess and records of paleoclimatic fluctuation

摘要

The carbonate Sr isotopic composition of the Heimugou loess-paleosol section in Luochuan of Shaanxi Province shows variation, with the ~87Sr/~86Sr ratios ranging from 0.7104 to 0.7120. The carbonate in paleosol has in general higher ~87Sr/~86Sr than the carbonate in loess. In the loess-paleosol section, the Sr isotopic composition vary with an about 100 ka periodicity, corresponding to the change of global glacial glacial cycle and comparable with the variation of Sr isotopic composition of paleosea water.