摘要
This study quantifies surface denudation of carbonate rocks by the first application of in-situ cosmogenic36Cl in China. Concentrations of natural Cl and in-situ cosmogenic36Cl in bare carbonates from Guizhou karst areas were measured with isotope dilution by accelerator mass spectrometer. The Cl concentration varied from 16 to 206 ppm. The 36Cl concentrations were in range of (0.8-2.4)106 atom g-1 , resulting in total denudation rates of 20-50 mm ka-1 that averaged over a 104-105 a timescale. The 36Cl-denudation rates showed roughly a negative correlation with the local mean temperature. This preliminary observation may suggest the variations of proportions of chemical weathering and physical erosion in denudation process, depending upon local climatic conditions.
This study quantifies surface denudation of carbonate rocks by the first application of in-situ cosmogenic 36C1 in China. Concentrations of natural C1 and in-situ cosmogenic 36C1 in bare carbonates from Guizhou karst areas were measured with isotope dilution by accelerator mass spectrometer. The C1 concentration varied from 16 to 206 ppm. The 36C1 concentrations were in range of （0.8-2.4）x106 atom g-l, resulting in total denudation rates of 20-50 mm ka-1 that averaged over a 104-105 a timescale. The 36Cl-denudation rates showed roughly a negative correlation with the local mean temperature. This preliminary observation may suggest the variations of proportions of chemical weathering and physical erosion in denudation process, depending upon local climatic conditions.
基金
supported by the National Natural Science Foundation of China (41130536 and 41021062)
the State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry, Chinese Academy of Sciences (9014)
