Tectonic geochemical characteristics and ore prediction in Hongdoushan copper deposit, Yunxian area, Western Yunnan

This paper systematically summarizes the mineralization conditions of the volcanic arc metallogenic belt in southern Lancang River and the geological features of the Hongdoushan ore district. The authors studied the tectonic geochemistry at 1272 and 1220 level. On the basis of the analysis of the data collected from tectonic rock samples and by means of R-type cluster analysis and factor analysis, the authors delineated combinational anomalies of mineralization elements. The authors found that the distribution of anomalies in the altered rock is controlled by NE-trending F₁ fracture and NWW-EW-trending F₃ fracture in the mining area. The zonation of high temperature and low temperature anomalies occur successively from fracture to surrounding rock, indicating the direction of fluid migration as well as the information of orebodies and provided evidence for deep ore prediction. Through the researches on structural ore-controlling regularity and tectonic geochemistry, the authors found the occurrence and deep extension of the NE-trending orebody, delineated the orebodies controlled by NWW-and nearly EW-trending fractures at the 1272 level. Field work demonstrated favorable ore-prospecting areas in the anomaly distribution zone and deep prediction target area, the copper orebody was delineated and predicted, which extends stably to the depth. The authors estimate that the resource reserves are about 50, 000 tons. The magmatic hydrothermal orebody controlled by tectonics has the prospect of reaching the medium copper deposit.