北祁连对尔山铜矿床地质特征及找矿前景分析

Mineralization Characteristics and Significance of the Duiershan Copper Deposits in Northern Qilian,Qinghai

对尔山铜矿产于北祁连早古生代辉长岩与玄武岩的接触部位,大地构造属走廊南山岛弧带。矿石具有海绵陨铁结构,具有似岩浆熔离型矿床的成因特点,矿点处为1：5万物探异常查证时圈定的CD-3磁异常,磁异常呈面状展布,强度中等,在-644-417nT,该异常由辉长岩引起;同时在CD-3磁异常的北西方向0.5-1.2km处,圈定出的CD-1磁异常、CD-2磁异常与矿点处CD-3磁异常具有相似的特点,经推断磁异常可能与辉长岩有关。矿点东、西两侧新发现2处地质背景、矿化特征、物化探异常与此类同的镍矿（化）点;另外,在CD-1磁异常处,圈定的1：5万36号水系异常主元素为Cu异常,解释推断认为是铜矿化引起。因此,认为对尔山一带具有寻找岩浆熔离型铜镍矿的良好前景。

The Duiershan copper deposit is formed in the contact place between Early Paleozoic basic gabbro and basalt in Northern Qilian,which is located in Nanshan island arc belt.The ore formed in sideronitic texture and has the similar characteristics of Magmatic deposit formation.The CD-3 magnetic anomaly has been delineated in 1/50000 geophysical anomaly verification,whichis caused by gabbro,spreading in planar distribution with nioderateintensity between-644-417 nT.While the CD-1 and CD-2 magnetic anomalies are 0.5-1.2km northwest of CD-3,and all of them have the similar characteristics.It＇ s concluded that CD-1 and CD-2 magnetic anomalies are related to gabbro.Two nickel oreoccurrences havebeen found in the east and west sides of CD-3 magnetic anomaly,with the similar geological background,mineralization characteristics,as well as geophysical and geochemical abnormity.Moreover,for the No.36 anomaly of 1/50000 stream sediment had been delineated in CD-1,the major element is concluded as the copper anomaly,which was caused by copper mineralization.In conclusion,the Duiershanarea has a great potential for prospecting the magmatic liquation Cu-Ni deposits.