Log-ratio transformation and PLS methods for identifying integrated geochemical anomalies: A case study of lead-zinc mineralization in northwestern Hunan
WANG Kun1, XIAO Ke-Yan2, CONG Yuan2
1. School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China;
2. Institute of Mineral Resources, CAGS, Beijing 100037, China
As lead-zinc deposits in northwestern Hunan are controlled by strata, the authors chose statistical regularities of constant elements in the ore-bearing layer as the basis of integrated geochemical anomaly extraction and used a stream sediment geochemical dataset. Firstly, three main forms of log-ratio transformation were used to explore the effects of the constant elements data closure problem. On such a basis, the PLS method was employed to study the integrated geochemical anomalies. The results show that data transformed by ilr method have obvious symmetrical statistical features and are much closer to the normal distribution. In contrast with PCA and FA, the integrated geochemical anomalies extracted by PLS method are generally more consistent with such geochemical features of lead-zinc mineralization in the study area as the known ore deposits and the fault distribution, and the results can be explained easier in geological field.
王琨, 肖克炎, 丛源. 对数比变换和偏最小二乘法在地球化学组合异常提取中的应用——以湘西北铅锌矿为例[J]. 物探与化探, 2015, 39(1): 141-148.
WANG Kun, XIAO Ke-Yan, CONG Yuan. Log-ratio transformation and PLS methods for identifying integrated geochemical anomalies: A case study of lead-zinc mineralization in northwestern Hunan. Geophysical and Geochemical Exploration, 2015, 39(1): 141-148.