【作者】 姚晓峰；

【导师】 唐菊兴；

【作者基本信息】 成都理工大学 ， 矿物学、岩石学、矿床学， 2010， 硕士

【摘要】 尕尔穷矿区属于冈底斯-念青唐古拉板片与南羌塘-三江复合板片缝合带西段,位于狮泉河晚燕山期结合带与冈底斯-念青唐古拉板片两大构造单元的交汇处。矿区地层为白垩系则弄群多爱组碳酸盐岩和火山碎屑岩,主要出露的侵入岩为燕山晚期的石英闪长岩、花岗斑岩和闪长玢岩等。矿区主矿体位于3-0-16线之间,呈北西走向,倾向北东,在走向上长大于900m,沿倾向方向延伸大于400米。矿体产于多爱组碳酸盐岩与石英闪长岩的接触带中,主要呈似层状和透镜状产出,其形态受岩体外接触带构造所控制。矿区有用元素以铜和金为主,矿石矿物以黄铜矿、斑铜矿和自然金为主,脉石矿物以矽卡岩矿物为主。矿石结构以结晶作用、交代作用和固溶体分离结构为主,矿石构造以稀疏浸染状和细脉状构造为主。通过研究矿石组构和矿物组合特征,石英闪长岩和花岗斑岩两次侵位分别存在有岩浆期、矽卡岩期和热液期。通过研究岩体的空间分布、形态和产状,岩石学、岩石化学和岩石地球化学特征,认为矽卡岩矿体的成矿母岩为石英闪长岩,提出花岗斑岩具有一定的成矿潜力。石英闪长岩和花岗斑岩属于钙碱性-高钾钙碱性的位于偏铝质和过铝质之间的过渡型花岗岩系列,具有铕弱负异常、轻稀土富集特征的稀土配分型式,具有富集大离子不相容元素Rb、K、Sr和亏损Th、Ta、Nb、Ti等高场强元素的微量元素地球化学特征。在总结不同类型岩体的含矿性评价思路及评价手段的基础上,建立矽卡岩型矿床成矿母岩的含矿性评价准则,从宏观到微观以区域地球化学块体、矿区岩石和矿物三个层次为主要的评价体系,各层次的含矿标志作为主要的研究内容。通过微量元素地球化学标志、岩石标志及矿物标志三方面指示岩体具有较好的含矿性,并预测矿区具有形成斑岩型矿床的潜力。更多还原

【Abstract】 Gaerqiong Copper-gold deposit belongs to the western suture zone of Gangdese-nianqintanggula plate and the composite plate of southern Qiangtang-Sanjiang rivers,located at the junction of the two structure unit that Shiquanhe-LateYanshan period junction zone and Gangdese-nianqintanggula plate.What the deposite diggings are carbonatite and pyroclasticrock which belongs to Duoai Formation of Zelong Group, Cretaceous system.The main emergence intrusiverock are quartz diorite, granite porphyry and diorite porphyrite of Late Yanshan period.The main ore body lied in the 3-0-16 line, over 900m in strike with NWW and over 400m in dip with NNE in length.The ore originated in the aureole belt of carbonatite and quartz diorite,outputing as bedded vein and lensing, and the form of which was controlled by the exomorphiczone structure of rock mass.The available element is mainly copper and gold, with major ore minera such as chalcopyrite、bornite and nature gold, and gangue mineral such as skarnmineral.The ore structure is priority to crystallization、solid solution isolated structure,and the texture is priority to sparsity disseminationstructure.According to study the form,it is presented that metallogenic epoch can be setted of magmatic stage、skarn stage and thermal metallogenic stage as twice intrusion of quartz dioriten and granite porphyry. According to study the space distribution、shape and attitude of the ore body,the characteristic of petrology、petrochemistry and lithogeochemistry,it is learned that the host rock of the skarn ore was quartz diorite and proposed that granite porphyry had certain mineralizing potential.Quartz diorite and granite porphyry pertained to the series of cal-alkaline and high-K calc-alkaline, transitional granite between peraluminous and metaluminous series, characterized by minor negative Eu anomalies and LREE enrichment in rare earth and the enrichment of large ion lithophile elements(LILE) such as Rb,K and Sr and depletion of high field strength element(sHPSE)such as Th,Nb,Ta and Ti of trace elements.Based on discussing the ore-bearing potential evaluated train of thought and evaluated methods of different type ore,raised ore-bearing potential interpretational criteria of skarnal host rock, established three layers as mainly evaluated series which were regional geo-chemistry block,rock and mineral in deposit from micro to macro level with the metallogenic information of each level as evaluation contents.It was discussed that the intrusive rock had a good mineralizing potential by the means of indication of petrology,mineralogy and geochemistry and the deposit shows a good potential of porphyry deposit.更多还原