Iconic Altered Mineral Assemblages on Prospecting Prediction by Hyperspectral Remote Sensing: Example from the Gold Deposits in Dongdatan and Xidatan Region of East Kunlun Mountain

The East Kunlun area is a very important and promising metallogenic belt in Qinghai Province, where developed an integrated orogenic gold metallogenic series. The metallogenic geological conditions in Dongdatan and Xidatan area have been analyzed in this paper. The results indicate that a good location-vacancy for metallogenic series of orogenic gold deposits exists in Dongdatan and Xidatan. Anomaly extracting results of hyperspectral data (CASI/SASI) indicate that seven types of altered minerals were mainly developed in this area, such as siderite, hornblende, chlorite, epidote, dolomite, calcite, long-medium-short wave of sericite. Different types of altered mineral groups reflect the distribution of shear zones in this region. Though developing the ground spectral measurements of the typical deposit by ASD instrument, this study summarizes the spectral characteristics of different geological units and altered minerals. It proposes that siderite+dolomite+medium wave sericite group is the iconic alteration mineral assemblages in this region. The prospecting criterion is the brittle-ductile shear zone that developed jarosite+limonitization. Combining the X-ray diffraction analysis of mineral composition in these rocks, it shows that the gold mineralization is closely related to regional metamorphism carbonate formnearation, which was controlled by the nearly EW brittle-ductile fault. Then, based on the iconic altered mineral assemblage of hyperspectrum anomaly and it predicts that there are two shear zones located in Wushibada Valley and Xidatan, with good prospecting potential of gold deposits. It also builds the gold prospecting model basing on high spectral information.