ANALYSIS METHOD OF METALLOGENIC CONDITIONS, DEPOSIT GENESIS, AND METALLOGENIC PREDICTION BASED ON 3D GEOLOGICAL MODEL: AN EXAMPLE FROM Xiyi Pb-Zn DEPOSIT, YUNNAN, CHINA

The Xiyi Pb-Zn deposit is located in a well-known mctallogcnic belt on the Baoshan block in the southern part of the Sanjiang Orogcnic System in China. Although several studies of the deposit have been conducted, the results have not been systematically utilized. In addition, a good deal of controversy remains concerning the deposit's genesis and its deep prospecting. In this study, a 3D geological model and a grade model of the boreholes, surface, strata, ore bodies, faults, and dikes in the main mining area were established to calculate the reserves of the main ore body, analyze the metallogenic conditions and genesis of the deposit, and to conduct an accurate prediction of unknown ore bodies that may exist deep within the strata. The results of our study show that the reserves of the main ore bodies, i.e., Pb and Zn, reach 901, 900 tons, suggesting a large Pb-Zn deposit. This deposit is similar to the Mississippi Valley-type (MVT) Pb-Zn deposit in tectonic setting and geological characteristics. Ore-bearing hydro-thermal fluid flows along fault F17, migrating from northeast to southwest within the deposit. The unknown ore bodies were accurately located, and the prediction levels were divided. The results of this study provide theoretical and technological support for the layout of surface boreholes. In addition, exploration was conducted based on the 3D spatial analysis of the mctallogcnic factors, deposit genesis, and metallogenic prediction.