摘要
为了研究木吉村斑岩型铜（钼）矿床蚀变过程中元素的迁移规律，拟推流体演化规律，笔者通过对赋矿闪长玢岩体的强硅化带、钾长石化带、石英绢云母化带、青磐岩化带中分别取样测试分析，利用Grant方程定量探讨了各蚀变带围岩中主量元素、稀土元素和微量元素的带入、带出特征，结果表明：岩浆初始热液流体富K而贫Na。相对原岩（蚀变弱的青磐岩化带），在各蚀变带中Fe2O3、MgO、P2O5和TiO2从深部强硅化带到浅部石英绢云母化带总体上由带出变为带入，SiO2、MnO则与上述大体相反，FeO在各蚀变带主体为带出元素。各稀土元素从深部向浅部石英绢云母化带带入特征明显，同时各蚀变带在稀土元素球粒陨石标准化曲线上表现出斜率一致的右倾型特征，说明轻重稀土分馏较明显，轻稀土富集，重稀土亏损。Cu和Mo在石英绢云母化带中富集尤为明显，其次在钾长石化带也明显富集，即海拔400~500m为主要的Cu、Mo富集区。
In order to deeply study the migration regularity of element and preliminarily infer the fluid evolution during alteration processes in the Mujicun Cu (Mo) deposit, the authors tested and analyzed the samples which were respectively collected from thestrongly silicified zone, the potassic zone, the quartz- sericitic zone and the propylitic zone in the ore- bearing diorite porphyritebody. Through calculation based on the formula by Grant, the authors made a tentative quantitative discussion on characteristics ofthe gains and losses of elements during their migration. The results demonstrate that mass migration of different elements showcertain regularities within the range of mineralized alteration: (1) the initial hydrothermal fluid is rich in K and is poor in Na.Compared with least- altered rocks (the propylitic zones), the losses of Fe2O3, MgO, P2O5 and TiO2 turn into the gains in alteredrocks from deep strongly silicified zone to shallow quartz-sericitic zone, with the generally opposite migration regularity of SiO2and MnO, and FeO is depleted in the three alteration zones. (2) The migration regularity of rare earth elements is similar to that ofFe2O3 and some other components. The REE curves assume a rightly dipping REE pattern, indicating obvious fractionation betweenLREE and HREE, with the enrichment of LREE and the losses of HREE. (3) Cu and Mo are especially enriched in the quartzsericiticzone and also relatively enriched in the potassic zone. These data suggest that the altitude of 400- 500 m in the dioriteporphyrite body is the main Cu and Mo enrichment area.
作者
陈超
牛树银
张建珍
马宝军
张福祥
孙爱群
王宝德
张醒
张浩亮
马国玺
陈志宽
CHEN Chao;NIU Shu-yin;ZHANG Jian-zhen;MA Bao-jun;ZHANG Fu-xiang;SUN Ai-qun;WANG Bao-de;ZHANG Xing;ZHANG Hao-liang;MA Guo-xi;CHEN Zhi-kuan(College of Resources, Hebei GEO University, Shijiazhuang 050031, Hebei, China;Baoding Institute of Geological Engineering and Exploration of Hebei Province, Baoding 071051, Hebei, China)
出处
《中国地质》
CAS
CSCD
北大核心
2016年第6期2118-2130,共13页
Geology in China
基金
国家自然科学基金(40872137)
河北省自然基金(D2015403013
D2013403018)
危机矿山项目(20109901
20089948)
河北地质大学博士基金(BQ201320)
河北省教育项目(ZC2016060)联合资助~~
关键词
幔枝构造
铜(钼)矿床
元素迁移
Grant方程
闪长玢岩
河北木吉村
mantle branch structure
copper (molybdenum) deposit
element migration
Grant equation
diorite porphyrite
Mujicun in Hebei Province
