• 岩石·矿床·地球化学 •

### 常用化学风化指标综述：应用与展望

1. 内生金属矿床成矿机制研究国家重点实验室，南京大学 地球科学与工程学院，南京 210023
• 出版日期:2022-02-20 发布日期:2022-02-20

### Overview of the Application and Prospect of Common Chemical Weathering Indices

LI Xulong，ZHANG Xia*，LIN Chunming，HUANG Shuya，LI Xin

1. State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
• Online:2022-02-20 Published:2022-02-20

Abstract: Common chemical weathering indices such as the Weathering Index of Parker (WIP), the Chemical Index of Alteration (CIA), the Index of Compositional Variability (ICV), CIX index and αAlE are often used to evaluate the chemical weathering intensity of source areas. But the factors which controlling the above chemical weathering indices should be considered, otherwise the results of the weathering evaluation will be distorted. This paper argues that the geological survey of source area should be known when chemical weathering indices are used to study the chemical weathering process. The selection of fine sediments or suspended matter can weaken the influence of grain size on chemical weathering indices. The impurities in the sediments are removed by acid treatment. Then, the Sc/Th-CIA diagram was used to reflect the material source information, Th/SC-Zr/Sc diagram was used to further distinguish the control effect of sedimentary differentiation and sedimentary recirculation, and then the samples with ICV value less than 1 were selected to eliminate the interference of recirculation. The A-CN-K diagram or the formula proposed by Panahi (2000) were used to correct the potassium metasomatism, and the strength of chemical weathering of source rocks was evaluated by CIA eventually. To ensure that the calculation of chemical weathering indices can accurately reflect the weathering situation of the source area, SPSS software can be used to analyze the proportion of some factors which affecting the CIA to construct characteristic weathering index of the study area.