安徽庐江泥河铁矿床蚀变-矿化作用及元素迁移规律  

Alteration-Mineralization and Element Migration Features of Nihe Iron Deposit in Lujiang,Anhui Province

作　　者：江满容[1] 张均[1] 刘文浩[1] 熊索菲[1] 

机构地区：[1]中国地质大学资源学院,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2015年第6期1034-1051,共18页Earth Science-Journal of China University of Geosciences

基　　金：全国危机矿山找矿典型矿床研究专项(No.20109904)

摘　　要：传统方法不能明确揭示泥河铁矿床多阶段热液叠加蚀变过程中元素迁移的继承性特征.运用等浓度图法(the isocon diagram),根据该区晚阶段蚀变都是叠加在稍早阶段蚀变之上的实际情况,采用早期蚀变岩石为原岩与稍晚期蚀变岩石的不活动元素拟合最佳等浓度方程,定量揭示主量元素在热液蚀变过程的迁移规律.研究表明,泥河铁矿床阳离子的沉淀顺序大致为:Na→Ca、Mg、Fe、P→Ca、Fe→Al、Si.从早到晚,元素的带入和带出是连续互补的,蚀变矿化作用是一个连续的过程.钠长石的大量出现是Na质沉淀的标志,代表铁矿化的开始;膏辉岩化是Ca、Mg、Fe质沉淀的表现形式,为磁铁矿体的近矿和容矿蚀变;次生石英岩化、高岭石化是早期迁移出的Al、Si质沉淀的结果,是磁铁矿化远程指示性蚀变.The inheritance of elements migration can’t be definitely revealed by traditional methods from Nihe iron ore deposit, which has a multi-stage hydrothermal superimposed alteration process.The quantitative features of the main and trace element migration in the process of hydrothermal alteration is presented in the paper by exploring its prospecting significance by adop-ting the early alteration rock for original rock and then fitting the best concentration equation between slightly late alteration rock with immobile elements by isocon diagram method.It is found that the cations precipitation sequence is roughly from Na to Ca,Mg,Fe,P to Ca,Fe and to Al,Si in Nihe iron deposit.As elements into and out of the system are continuous comple-mentary for both early to late alterations,the alteration and mineralization are considered as a continuous process.The exten-sive albitization is a sign of Na qualitative precipitation,marking the beginning of iron ore mineralization.Anhydrite-diopside mineralization is the result of Ca,Mg and Fe qualitative precipitation which is the ore-closing and ore-hosting alteration.Sec-ondary quartzite and kaolinization is the Al,Si qualitative precipitation migrated from early alteration,which is the long-dis-tance indicative alteration of magnetite.

关 键 词：元素迁移 蚀变矿化带 铁矿床 地球化学. 

分 类 号：P614[天文地球—矿床学]