玲珑金矿田含矿断裂的基岩地球化学特征及找矿潜力评价

Bedrock Geochemical Characteristics and Prospecting Potential Evaluation of Ore-Bearing Faults in Linglong Gold Ore-field

基岩地球化学方法广泛应用于地质找矿与生产实践,是开展深部找矿预测最直接的方法和手段。通过对玲珑金矿田井下含矿断裂和招平断裂的基岩剖面地球化学特征进行系统研究,得出以下认识:玲珑金矿田原生晕最佳指示元素组合为Au、Ag、Bi、As和Co,且Au-Ag、Au-Bi、Au-As及Au-Co元素之间呈较好的幂指数正相关。根据玲珑金矿田已探明矿脉最佳指示元素组合的统计结果,结合招平断裂基岩剖面地球化学测量结果,发现招平断裂在地表有2处金矿化异常,推测其为矿致异常,反映出该地段具有较好的找矿潜力,特别是前花园村东1021剖面中异常找矿潜力更大。

The mineralization of Linglong gold ore-field is controlled by faults.In the process of gold mineralization,the fault is not only the channel of mineralization fluid,but also the surrounding rocks in direct contact with mineralization fluid.The fluid and wall rocks on both sides of the fault must have metasomatic reactions.Therefore,it is of great significance to study the geochemical characteristics of bedrock in fault profile for metallogenic research and prospecting prediction.Based on the study of geochemical characteristics of bedrock profiles of ore-bearing faults and Zhaoping fault in Linglong gold field,taking ascertain orebody as research template,a comprehensive study of the correlation between Au and other trace elements in orebodywall rock,lean-rich ore,local-whole was conducted.Combined with mineralogical characteristics and geochemical characteristics of element halo of gold deposit,application research on metallogenic prediction of unknown orebodies was performed.Regarding 7 orebodies profile as the research object,by comparing the correlation between Au and trace elements in orebody and surrounding rock,the variation characteristics and correlation of trace elements in orebody profile in local range were analyzed,and the best indicator elements of Au in typical orebodies in the ore field were summarized.According to the gold grade,352 orebodies can be divided into five types(super rich ore,rich ore,lean ore,super lean ore,surrounding rock).The average content of trace elements in various orebodies was counted,and the difference in the indication meaning of trace elements in rich and poor ores was compared.On the premise of a large number of sample data statistics,the correlation between Au and other trace elements in the Linglong ore field was summarized through scatter plots.Combined with the occurrence form of gold and various trace elements,the geological significance of Au and various trace elements,and the diagenesis and mineralization mechanism of Linglong gold ore field were discussed.The above research results were applied to other faults in Linglong gold field,and the primary halo geochemical halo method was used to predict fault mineralization.The following understandings are obtained:The best indicator element combination of primary halo in Linglong gold field is Au,Ag,Bi,As and Co,and the positive correlation of power exponent among Au with Ag,Bi,As and Co elements is good.Gold exists in the form of silver gold ore,mainly in the form of fine grains or veins in the fissures and crystal gaps of pyrite.The geochemical survey of bedrock profile of Zhaoping fault shows two gold mineralization anomalies,which are supposed to be ore-induced anomalies and have good prospecting potential,especially in the 1021 profile of east Qianhuayuancun.Based on the geochemical survey method of bedrock in fault profile,the prospecting object is expanded by changing prospecting into halo,and the deep metallogenic prospect can be predicted according to the difference of halo forming element distribution.