Abstract: Xiaoyuanshan Fe-polymetallic mining area is located in the Qimantage ophiolite melange belt,which is one of the important Fe-polymetallic metallogenic belts in Qinghai Province.Many magnetic anomalies closely related to Fe-polymetallic mineralization are delineated in the mining area by conducting geological investigation work of Fe-polymetallic deposit,it is show that the metallogenic potential of the mining area is good.Based on the analysis of regional metallogenic geological background and geological characteristics of the mining area,the deposit geological characteristics and ore-controlling factors are discussed in depth.The study results show that:①the main surrounding rock formations are favorable for the formation of Fe-polymetallic mineralization,the metallogenic elements of W,Sn and Cu are enriched in Baishahe Rock Formation (Pt₁b) of Jinshuikou Rock Group,carbonate rocks is hosted in stratum rocks (such as Tanjianshan Group) of Ordovician-Silurian,so the favorable surrounding rock conditions of Fe-polymetallic occurrence in Xiaoyuanshan mining area is provided;②17 magnetic anomalies with the mainly NWW-direction in the mining area are delineated,which show that the geological structure is one of the main ore-controlling factors of the metallogenic of Xiaoyuanshan Fe-polymetallic deposit;③the Fe-polymetallic deposits are mainly distributed in the contact belts of intermediate-acidic intrusive rocks and surrounding rocks,the distribution of orogenic type deposit is controlled by the intrusive rock bodies of the Late Variscan and Indosinian-Yanshanian,thickness of the Fe ore-bodies is 0.90~5.91 m,the TFe grade is 21.85%~44.34%,thickness of the Pb-Zn mineralized bodies is 0.10~5.45 m,the grade of Zn is 0.79%~13.60%,the grade of Pb is 0.63%~6.88%,which show that the prospecting potential in the mining area is good;④genesis of Xiaoyuanshan Fe-polymetallic is the typical skarn type deposit closely related to acidic magma,and it is controlled by the specific carbonate ore-hosed rocks,fracture tectonic position and magmatic hydrothermal activities.Based on the above analysis results,the prospecting potential of the mining area is studied,the results show that the superimposed area of magnetic anomalies and stream sediments elements anomalies,Tanjianshan Formation of Ordovician-Silurian and the Shiguaizi Formation of Carboniferous,and the tectonic positions such as the large faults and its adjacent fracture belts,magmatic intrusion belt are the favorable prospecting areas of Xiaoyuanshan mining area.

Key words: Fe-polymetallic deposit, Skarn type deposit, Geological characteristics, Deposit genesis, Ore-controlling factor, Prospecting direction