Identification and assessment of Sn-polymetallic prospects in the Gejiu western district, Yunnan (China)

- A combination of Factor analysis (FA) and spectrum-area (S-A) fractal model is useful to separation of geochemical anomalies.
- Ore-forming element content in distinct lithologic sections was studied.
- The modeling semi-variogram utilizes to know how important controlling factors are to geochemical anomalies.

The Gejiu mineral district, which is a world-class tin production region, is currently facing a shortage of resources; therefore, mineral exploration in the deeper and peripheral spaces has become a high priority in this old mine. Douyan district, located in the south of the Gejiu western district, is becoming the focus of mineral exploration for its favorable metallogenic geological conditions. In this study, factor analysis (FA) and a spectrum-area (S-A) fractal model, aided with geostatistics are applied to study the integrated primary geochemical anomalies associated with Sn polymetallic mineralization. The results indicate that (1) both the F3 and F5 include the information associated with Sn mineralization. F5-consisting of Sn and Sr, indicates that part of the ore-forming materials come from carbonate rocks. F3-consisting of Sn and Mo, shows magmatic activities, which would provide the ore-forming thermal conditions. (2) Sn prospects have been explored in Shuitang Mountain to the SE of study area, and the identified anomalies are related to volcanic rocks and alteration zones. (3) The key controlling factors of geochemical anomalies are the SW-trending fault (Douyan-Shuitang fault), stratus and granitoid batholiths based on geological information.