大兴安岭北部东方林场银异常找矿前景

THE ORE-PROSPECTING VISTA OF THE SILVER ANOMALIES IN DONGFANG TREE FARM OF NORTHERN DA HINGGAN MOUNTAINS

位于得尔布干成矿带北东段、大兴安岭火山岩带北部的东方林场银异常为Ag、Mo、Zn、Au、As组合异常,Ag异常主要为面状分布,但高值异常也有呈带状分布者。异常规模可观,具浓度分带,有浓集中心,异常标准离差、衬度值及峰值高,局部还伴生高值钼异常。异常区有面状泥化蚀变,剥蚀程度低,与同一成矿带的乌奴格吐山大型斑岩铜钼矿床在成矿地质条件、异常特征等方面有许多相似之处,也有一些不同之点。因此异常区除具有非常好的寻找斑岩型银(金)多金属矿床的前景外,也有找到热液脉状银(金)多金属矿床的可能。

The Dongfang tree farm in northern Da Hingganling volcanics belt is situated in the northeastern part of the Deerbugan metallogenic belt. Its silver anomalies are Ag, Mo, Zn, Au and As composite anomalies. The Ag anomalies mainly assume planar distribu- tion, with some high-value anomalies in zonal distribution. The anomalies are large in size, and have concentration zoning, concentration centers and high standard deviations as well as high threshold values, associated locally with Mo anomalies. The anomaly area shows planar argillation alteration and low denudation degree, quite similar to the Wunugetushan large-size porphyry Cu-Mo deposit in the same metallogenic belt in ore-forming geological conditions and anomaly characteristics. Besides having very good vista in prospecting for porphyry Ag （Au） polymetallic deposits, the anomaly area is likely to have hydrothermal veinlike Ag （Au） polymetallic deposits.