【摘要】 为探讨九星铁矿床的成矿与围岩(赋矿地层)的关系,系统采集了九星铁矿床赋矿变质围岩(绿泥石片岩和绿泥石千枚岩)样品进行元素地球化学分析。结果表明,两类赋矿变质围岩有如下特点:高硅铝、富钾镁且碱质总量偏低;富集大离子亲石元素,亏损高场强元素;轻稀土相对富集,重稀土相对亏损,轻重稀土分馏明显,具有Eu负异常与弱Ce正异常。赋矿变质围岩的原岩为铁质泥岩及纯泥质岩,沉积原岩物源主要为酸性火山岩区的长英质物源或长英质与基性岩混合物源,构造背景为被动大陆边缘。稀土元素示踪结果显示九星铁矿床磁铁矿与围岩稀土元素配分特征基本一致,综合分析认为九星铁矿床的成矿物质主要来源于围岩(赋矿地层)。更多还原

【Abstract】 In order to constrain the relationship between mineralization and wall rocks in the Jiuxing Fe deposit,whole rock geochemistry of wall rocks from the deposit are systematically analyzed. The results show that both chlorite phyllite and chlorite schist have high silicon,aluminum,potassium and magnesium,low sodium and calcium and total alkalinity.They are characterized by relative enrichment of large ion lithophile elements and depletion of high field strength elements.The rocks are enriched in LREE,relatively depleted in HREE and display significant fractionation between LREE and HREE. Both two types of the rocks have strong negative Eu anomalies and weak positive Ce anomalies,indicating that they were deposited in a weakly reduced environment. The source rocks of both chlorite phyllite and chlorite schist were ironrich mudstone and mudstone,which were mainly originated from felsic rocks or the mixture of felsic and basic rocks at the passive continental margin. In addition,magnetite of the deposit has similar REE patterns as wall rock. All geochemical features of magnetite and wall rock suggest that ore metals are mostly from the strata.更多还原