陕西略阳南部白雀寺基性杂岩体何家垭铜镍矿的发现及找矿方向

The Discovery and Prospecting Direction of Cu-Ni Ores in the Baiqisi Basic Complex in South Lüeyang County of Shaanxi Province

何家垭铜钴镍矿在陕西省秦岭造山带同类矿床中较为罕见,其成矿类型及成矿条件在同类矿床中具有特殊性。本文基于已有的矿化线索,使用重、磁、电等多种物探方法对矿化点进行研究。激电中梯剖面测量和对称四极测深显示了矿体的展布特征,即在平面上呈北东向带状分布,在深部沿对称四极测深DHJC3极化率异常带西侧外接触带延伸。经钻探验证,发现铜、钴、镍矿体2条,主矿体厚度13.65 m,镍平均品位为0.496%,钴平均品位为0.050%,铜平均品位为0.335%。综合研究认为,新发现的铜、钴、镍矿带附近岩体具有水平和垂向分异的特征,在平面上岩体岩性自西向东由中基性过渡为中性,在垂向上岩体岩性由浅至深呈中性-中基性-基性分布。综合分析本区地质-地球物理特征,并结同类型矿床成矿规律,认为何家垭铜镍矿床与岩浆分异作用有关,矿体赋存于中性与基性岩浆过渡带靠近基性岩体一侧,金属硫化物引起的中高极化异常是找矿的重要标志。

The Hejiaya copper-cobalt-nickel deposit is relatively rare among similar deposits in the Qinling orogenic belt of Shaanxi Province,with unique metallogenic type and conditions compared with similar mineral deposits.On the basis of known mineralization clues,this work conducted integrated gravity,magnetic and electrical surveys to study the mineralized spots.IP intermediate gradient survey and symmetrical quadrupole sounding define the distribution of orebodies.In the plane,the orebodies display NE-trending zonal distribution.In the vertical direction,the orebodies extend along the western outer contact zone of the DHJC3 polarizability anomaly zone in symmetrical four-pole sounding.Drilling verification has discovered two copper-cobalt-nickel orebodies,with a thickness of 13.65 m for main orebodies,and the Ni,Co and Cu grades are at 0.496%,0.050%and 0.335%,respectively.Comprehensive analysis shows that the newly discovered rock mass near the copper,cobalt and nickel ore belts has horizontal and vertical zonation.In the plane,the rock mass changed from intermediate-basic rock to intermediate rock from west to east.In the vertical direction,the rock mass displays an intermediate and intermediate-basic to basic distribution from shallow to deep.Comprehensive geological-geophysical analysis,as well as the metallogenic regularity of the same type of deposits in this area,reveals that the Hejiaya copper-nickel deposit is related to magma differentiation.The orebodies are located in the transition zone between intermediate and basic rocks,and are close to the basic rocks.The middle-high polarization anomalies caused by metal sulfides are an important prospecting clue.