Geochemical characteristics of stream sediments and prediction of mining prospects in the Wulandaban—Zhazigou area, Danghe South Mountain, Gansu Province

Danghe South Mountain is located at the northern edge of South Qilian massif, bounded by the Danghe River, and neighbors the central Qilian massif in the north. It belongs to the South Qilian Au, Pb, Zn, Cu, Ni, W, and Cr metallogenic belt. The gold deposit is the main mineral species in the metallogenic belt. It is known as 72 gold ditches. At present, two large or medium-sized gold deposits have been discovered, and there are more than ten small gold ore spots. Wulandaban-Zhazigou area is located in the middle of the Danghe South Mountain. A large number of gulch-gold mining sites can be seen in the area, showing good geological conditions for prospecting in this area. Based on the investigation and study of the area, the authors analyzed the geochemical characteristics, elemental distribution characteristics, elemental correlation and abnormal elemental combination characteristics in the study area by using 1:50, 000 stream sediment survey. Combined with the geological conditions such as strata, structures, magmatic rocks and mineralization alteration characteristics in the area, the authors delineated the metallogenic prospective areas. Through this work, 11 metallogenic prospective areas of gold were delineated which could be divided into three types. The first type includes the south of Zhazigou, Diaoyugounao, Diaoyugou, Hongmiaogou and Beijiazi-Wulandabangou metallogenic prospective areas. The authors also discussed the minerogenetic condition and put forward some suggestions concerning further work in the first type metallogenic prospective areas. Delineation of the metallogenic prospective areas provides important reference for further prospecting work.