GEOCHEMICAL ANOMALY EXTRACTION USING FACTOR ANALYSIS METHOD BASED ON MAPGIS DIGITAL ELEVATION MODEL
SHI Wen-jie1, WEI Jun-hao1, ZHANG De-cai2, ZHAO Shao-qing1, CHEN Chong1, GAO Xiang1, ZHAI Ya-feng1, YI Jian1
1. Faculty of Earth Resources, China University of Geosciences, Wuhan 430074, China;
2. No. 2 Institute of Geological and Mineral Exploration of Inner Mongolia, Bayannur 015000, China
This paper analyzed the 1∶50000 rock-scrap data obtained from northwestern China, using the R-mode factor analysis method. Geochemical subdivisions were carried out with the extracted five representative factors from the data. Then the authors decided factor F3 (Cu-Zn-Ag) which was related to mineralization, in comparison with regional mineralization characteristics, geological conditions and mineralization in the study area. Geochemical anomalies were extracted with the factor analysis method based on MAPGIS digital elevation model. The result suggests that the anomalies are well consistent with 76% Cu mineralizations, raising the efficiency by 10% in comparison with the single element copper geochemical anomalies. The main anomalies are located in Gongpoquan Group, particularly in the contact zone with parts of magmatic rocks. Mineralizations were found in most of the anomalies. In addition, some small anomalies were found in the K-feldspar granite, and field anomalies inspection has proved that these anomalies are caused by limonitization and malachite of quartz veins and K-feldspar granite. The project of trench has also proved the superiority of the method in the medium-large scale anomaly extraction.
