北秦岭翠华山-库峪一带晚中生代花岗岩黑云母地球化学特征及成因  

Geochemical characteristics and genesis of biotites from Late Mesozoic granites in the Cuihuashan-Kuyu area,North Qinling

作　　者：陈楠[1] 黄艳娜 黎敦朋 付一航 杨小敏 CHEN Nan;HUANG Yanna;LI Dunpeng;FU Yihang;YANG Xiaomin(Zijin School of Geology and Mining,Fuzhou University,Fuzhou,Fujian 350108,China;The Second Geological Exploration Institute,China Metallurgical Geology Bureau,Fuzhou,Fujian 350108,China)

机构地区：[1]福州大学紫金地质与矿业学院,福建福州350108 [2]中国冶金地质总局第二地质勘查院,福建福州350108

出　　处：《福州大学学报（自然科学版）》2024年第4期496-504,共9页Journal of Fuzhou University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(41872220)。

摘　　要：为探讨北秦岭造山带晚中生代岩浆复杂多样的成因机制,以北秦岭中段翠华山、大峪及库峪地区晚中生代二长花岗岩为研究对象,利用电子探针技术对其中的黑云母进行地球化学分析.结果显示,所采样品中的黑云母主体属于镁质黑云母,其成因类型为原生黑云母.矿物化学数据计算结果显示,翠华山、大峪及库峪二长花岗岩样品中黑云母的结晶压力均值分别为205、202、211 MPa,对应结晶深度分别为7.8、7.6、8.0 km,结晶温度均值分别为711、653、657℃,氧逸度均值分别为-16.45、-18.40、-18.27.基于上述结果分析,揭示研究区二长花岗岩主要物质来源于地壳并有少量幔源物质加入,翠华山、大峪及库峪二长花岗岩具有I型花岗岩亲缘性,均属于造山带钙碱性花岗岩系.In order to discuss the complex and diverse genetic mechanism of Late Mesozoic magmas in the North Qinling orogenic belt,this paper takes the Late Mesozoic monzogranite in Cuihuashan,Dayu and Kuyu areas in the middle part of the North Qinling as the research object,and uses the electron probe technology to make geochemical analysis of the biotite in the monzogranite.The results show that the main body of biotite in the samples belongs to magnesian biotite,and its genetic type is primary biotite.The calculated mineral chemistry data show that the average crystallization pressure of biotite in Cuihuashan,Dayu and Kuyu monzogranite samples is 205,202 and 211 MPa,the corresponding crys-tallization depths is 7.8,7.6 and 8.0 km,and the average crystallization temperature is 711,653 and 657℃,respectively.The mean values of oxygen fugacity were-16.45,-18.40 and-18.27,respec-tively.Based on the above results,it is revealed that the monzogranites in the study area are mainly derived from the crust with a small amount of mantle-derived materials added,and the Cuihuashan,Dayu and Kuyu monzogranites have I-type granitic affinities and belong to the orogenic calc-alkaline granite series.

关 键 词：北秦岭 二长花岗岩 黑云母 岩石成因 

分 类 号：P548[天文地球—构造地质学] P588.12[天文地球—地质学]