摘要
东昆仑祁漫塔格-都兰成矿带是青海省重要的矽卡岩型铁多金属成矿带,胜利矽卡岩型铁铜矿床位于该成矿带东段,其成矿作用与二长花岗岩密切相关,矿体产于二长花岗岩与大理岩接触带的矽卡岩中。地球化学数据显示,胜利铁铜矿床二长花岗岩w(SiO_2)为71.84%～74.50%,w(K_2O+Na_2O)为8.03%～8.61%,明显富碱;K2O/Na2O为1.28～1.62,相对富钾;A/CNK为0.95～0.98,属于准铝质高钾钙碱性Ⅰ型花岗岩。岩石总体富集大离子亲石元素K、Ba、Rb和活泼不相容元素Th、U,相对亏损高场强元素Ta、Nb、P、Ti等。样品稀土元素总量w(∑REE)=132.73×10^(-6)～181.36×10^(-6),(La/Yb)_N为7.40～11.67,δEu为0.67～0.78,稀土元素配分曲线呈右倾型,具有较明显的轻稀土元素富集、重稀土元素亏损的特征,具Eu负异常。二长花岗岩LA-ICP-MS锆石U-Pb加权平均年龄为(240.5±2.8)Ma,形成于中三叠世。综合研究表明,二长花岗岩是阿尼玛卿洋盆向北俯冲,致使壳幔岩浆发生混合,后经侵位、结晶分异形成。
The Qimantag-Dulan metallogenic belt is an important skarn-type iron-polymetallic metallogenic belt in East Kunlun,Qinghai Province,and in its eastern part lies the Shengli iron-copper deposit.The mineralization shows a close relationship with monzogranite,and the orebodies mainly occur in the skarn.The monzogranite displays enrichment in SiO2（71.84%-74.50%）,Al2O3（13.38%-14.55%）,Na2O（3.20%-3.68%）and K2O（4.72%-5.27%）,with high K2O/Na2O ratios（1.28-1.62）and middle A/CNK（0.95-0.98）,suggesting the monzogranite is high potassic calc-alkaline and metaluminous granite.Meanwhile,the monzogranite exhibits right-inclined type REE pattern and depletion in high field strength elements（Ta,Nb,Ce,P and Ti）,and enrichment in large ion lithophile elements（LILE：Rb,Th,U,K and Pb）and light rare earth elements（LREE）,with total rare earth elements（Σ REE）of 132.73×10^-6-181.36×10^-6.Zircon LA-ICP-MS U-Pb dating yields ages of（240.5±2.8）Ma（MSWD=0.93）,indicating their formation in Middle Triassic.The result suggests that the monzogranite maybe generated by the animating ocean basin with north-dipping subduction and the magma was triggered by the process of mixing,emplacement and crystal1 ization differentiation during the crust-mantle interaction.
作者
姚学钢
周帅
贾群子
李金超
孔会磊
国显正
王宇
Yao Xuegang;Zhou Shuai;Jia Qunzi;Li Jinchao;Kong Huilei;Guo Xianzheng;Wang Yu(Institute of Geological Survey,China University of Geosciences（Wuhan）,Wuhan 430074,China;Xi＇an Centerfor Geological Survey,CGS,Xi＇an 710054,China;Qinghai Haixin Mining Company Limited,Xining 810300,China)
出处
《地质科技情报》
CSCD
北大核心
2018年第5期11-20,共10页
Geological Science and Technology Information
基金
中国地质调查局项目"东昆仑铜镍多金属资源基地调查"(DD20160013
121201011000150005-17)
