吉林省桦甸市五里营金多金属矿地质特征及找矿标志

Geological Characteristics and Prospecting Indicator of Wuliying Au-polymetallic Deposit in Huadian County,Jilin Province

吉林省桦甸市五里营金多金属矿大地构造位置位于松嫩地块南缘,西拉木伦河缝合带以北,伊依断裂与敦密断裂之间,居于吉中Mo-Ag-As-Au-Fe-Ni-Cu-Zn-W成矿带内,区内地层发育,构造、岩浆活动频繁,成矿地质条件优越。结合该区地质调查、物化探工作成果,详细分析了区内矿床地质特征及地球物理、地球化学特征。研究表明:(1)区内地层主要有二叠系中统范家屯组、大河深组及第四系,区内褶皱构造为NNE向大顶子—新立屯背斜中段,断裂构造主要为NE向大河深—常山压扭性断层,两者为区内的控矿构造;(2)区内围岩蚀变类型主要为高岭土化、硅化、绿泥石化、碳酸盐化、黄铁矿化以及褐铁矿化,其中,硅化+黄铁(褐铁)矿化与金、锑矿关系密切;(3)根据1∶10 000土壤地球化学测量成果圈定了Ⅰ类靶区2个(编号分别为Ⅰ-1#,Ⅰ-2#),Ⅲ类靶区1个(编号为Ⅲ-1#),其中,Ⅰ-1#靶区成矿条件较为优越,推测该区深部存在隐伏金矿体的可能性较大;Ⅰ-2#靶区内可见块状辉锑矿化、偶见浸染状黄铁矿化,反映出该区锑、金矿找矿前景较大。在上述讨论的基础上,进一步分析了矿床成因并总结了找矿标志,认为区内矿床成因类型应属燕山早期中—低温岩浆期后热液型矿床;地层、岩浆岩、控矿构造、矿化蚀变、物化探异常等为该区有利的找矿标志。

The geotectonic position of Wuliying Au-polymetallic deposit in Huadian County,Jilin Province is located at the south of Songnen massif and the north of Xilamulun River suture zone,it is distributed between Yiyi fault and Dunmi fault. In general,the Au-polymetallic deposit is located in Mo-AgAs-Au-Fe-Ni-Cu-Zn-W metallogenic belt in the central of Jilin Province,the strata in the mining is well developed,tectonic and magmatic activities occur frequently,the metallogenic geological condition of the mining area is good. Based on the geological investigation results and geophysical and geochemical surveying results,the geological characteristics of the ore-bodies,geophysical characteristics and geochemical characteristics of the working area are discussed. The study results show that：（1）the strata developed in the area are mainly for Fanjiatun Formation,Daheshen Formation of Middle Permian,the fold structure is the middle section of NNE trending Dadingzi-Xinlitun anticline,fracture structure is mainly for NE trending Daheshen-Changshan compressive torsional fault,both of them are belongs to the ore-controlling structures in the working area;（2）the surrounding rock alteration of the working area is mainly for kaolinization,silicification,chloritization,carbonatization,pyritization and ferritization,among of them,silicification,pyritization and ferritization are closely related to gold and antimony deposit;（3） based on the1∶ 10 000 soil geochemical surveying results,two target areas belongs to level one（named Ⅰ-1#,Ⅰ-2#）and one target area belongs to level three（named Ⅲ-1#） are delineated,the metallogenic conditions ofⅠ-1#area is superior to the others,it is inferred that the existence probability of concealed gold orebodies in the depth is high; massive antimonite mineralization is developed in Ⅰ-2#target area,disseminated pyritization can be found occasionally,which indicated that the prospecting potential of gold and antimony deposit is good in the target area. Based on the above analysis results,the deposit genesis is discussed and the prospecting indicators are summarized. The results show that deposit genesis of the working area is belongs to Early Yanshanian medium-low temperature post-magmatic hydrothermal type deposit,besides that,stratum,magmatic rock,ore-controlling structure,mineralized alteration,geophysical and geochemical anomalies can be regarded as favorable prospecting indicators in the area.