滇西北格咱铜多金属矿集区含矿斑岩、不含矿斑岩与全球埃达克岩对比研究

Comparative Study of Ore-bearing Porphyry,Non-ore-bearing Porphyry and Global Adakite in Geza Copper Polymetallic Ore-concentrated Area,Northwestern Yunnan

云南格咱铜多金属矿集区是西南三江构造—岩浆岩带中义敦岛弧的重要组成部分,位于义敦岛弧带的南端,是三江多岛弧成矿带内重要的斑岩-矽卡岩型铜钼多金属矿产地之一。系统整理了区内15个代表性成矿斑岩体768件岩石地球化学数据,依据Cu含量分为含矿和不含矿两类数据,并与全球埃达克岩数据进行对比研究。采用大数据分析方法,计算了不同元素含量对比值,进行投图后获得交叠率较好的图件共14340幅。研究表明:格咱铜多金属矿集区斑(玢)岩体具有全球埃达克岩属性,但又独具特点,具有明显的高钾性特征。与以高钾钙性系列和钾玄岩系列为主的中国东部埃达克岩特征相似,该区斑(玢)岩体具有更高的w(Al_(2)O_(3))/w(Co)、w(Al_(2)O_(3))/w(Mo)值;相对于不含矿岩体,含矿岩体中Ba、V、Ni、Co等元素的含量区间较为集中,且w(Al_(2)O_(3))/w(Mo)值明显偏低,为格咱铜多金属矿集区岩体含矿性的判别研究提供了科学依据。

The Geza copper polymetallic ore-concentrated area in Yunnan is an important part of the Yidun island arc in the Sanjiang tectonic-magmatic belt in Southwest China.It is located in the southern end of the Yidun island arc belt and is one of the important porphyry-skarn copper-molybdenum polymetallic deposits in the Sanjiang metallogenic belt.In this paper,768rock geochemical data of 15 representative ore-forming porphyry bodies in the region are systematically sorted out.According to the copper content,the data are divided into ore-bearing and non-ore-bearing data,and compared with the global adakite data.Using big data analysis method,the comparison values of different elements are calculated,and a total of 14340 maps with good overlap rate are obtained after projection.Studies have shown that the porphyrite rock mass in the Geza copper polymetallic ore-concentrated area has the global adakite attribute but unique characteristics,and has obvious high potassium characteristics.Similar to the characteristics of adakite in Eastern China dominated by high-potassium calcic series and potassium basalt series,the porphyrite rock mass in this area has higher w(Al_(2)O_(3))/w(Co)and w(Al_(2)O_(3))/w(Mo)values.The element contents of Ba,V,Ni and Co in ore-bearing rock are relatively concentrated,and the w(Al_(2)O_(3))/w(Mo)ratio is obviously lower than that in non-ore-bearing rock,which provides a scientific basis for the study of ore-bearing rock in Geza copper polymetallic ore-concentrated area.