甘肃大水金矿田埃达克岩特征及成矿物质来源  

The Geochemical Characteristics of Adakite Rock and the Source of Metallogenetic Material in Dashui Goldfield of Gansu Province

作　　者：李注苍[1,2] 李永军[1] 杨志勇[2] 雷祥军[2] 李作鹏[2] 缪斌[2] 

机构地区：[1]长安大学地球科学与国土资源学院西部矿产资源与地质工程教育部重点实验室,陕西西安710054 [2]甘肃省地矿局第三地质矿产勘查院,甘肃兰州730000

出　　处：《新疆地质》2014年第2期250-254,共5页Xinjiang Geology

基　　金：1∶5万玛曲幅、桑木差幅区域地质矿产调查(GSQDW1993-27)资助

摘　　要：对大水地区印支晚期忠格扎拉岩体、忠曲岩体、格尔括合岩体的岩石学、岩石地球化学特征研究得出,SiO2含量为58.40%-63.95%,大于56%;A12O3含量为15.18%-16.66%,大于15%;MgO含量为1.31%-2.91%,小于3%;Sr含量为1 410×10-6-576×10-6,大于400×10-6;Y含量为12.2×10-6-15.3×10-6,小于18×10-6;Sr/Y比值42.57-85.52,大于40;（La/Yb）N比值为19.38-35.97,大于10,与典型埃达克岩特征基本一致。表明它们来自于基性下地壳部分熔融,埃达克岩的高温和高压萃取了大量Au元素,形成富金含矿热液,并沿构造通道上升沉积于三叠纪地层中,形成大水金矿田。Study the petrology,geochemistry characteristics of the Zhonggezhala rock,Zhongqu rock and Geerkuohe rock which were become in the late indo-Chinese epoch. SiO2content is 58.40%~63.95%〉56%;A12O3content is 15.18%~16.66%〉15%;MgO content 1.31%~2.91%〈3%;Sr content 1410×10-6~576×10-6〉400×10-6;Y content is 12.2×10-6~15.3×10- 6〈18×10- 6;Sr/Y ratio is 42.57~85.52〉40;（La/Yb）Nratio is 19.38~35.97〉10.They have the same characteristics with the typical adakite ones that suggests they come from the situation of partial melting of under-crust.The adakite rock have high temperature and high pressure which can extracte a large amount of Au element and they form a abundence ore-bearing hydrothermal, rising along the tectonic channel deposition to the Triassic strata,formed the Dashui gold ore field.

关 键 词：大水 金矿 埃达克质岩 花岗岩类岩石 地球化学 

分 类 号：P618.51[天文地球—矿床学]