河南新蔡练村铁矿床地质特征与成矿构造背景  

Geological characteristics and metallogenic tectonic background of Xincai Liancun iron deposit in Henan Province

作　　者：杨崇科[1] 卢欣祥[2] 杨延伟[1] 刘心宁[1] YANG Chongke;LU Xinxiang;YANG Yanwei;LIU Xinning(The First Team of Henan Coal Field Geological Bureau,Zhengzhou 450000,Henan,China;Henan Academy of Land and Resources Sciences,Zhengzhou 450053,Henan,China)

机构地区：[1]河南省煤田地质局一队,河南郑州450000 [2]河南省国土资源科学研究院,河南郑州450053

出　　处：《矿产与地质》2018年第6期1027-1034,共8页Mineral Resources and Geology

基　　金：河南省科技攻关项目"河南省锂矿成矿规律与找矿方向研究"(编号:2018-132-1)资助

摘　　要：新蔡铁矿床位于华北克拉通南缘舞阳—霍邱铁矿成矿带中部,是连接西部舞阳铁矿与东部霍邱铁矿的关键部位,矿体主要呈层状、似层状产于新太古界太华岩群变质岩系中。在研究新蔡地区铁矿床地质特征的基础上,对新蔡地区典型矿床练村铁矿床的矿石及围岩进行系统的主微量元素分析,探讨其成矿构造背景。在稀土配分模式上,铁矿石与原岩为杂砂岩及硅铁沉积物的石英岩类、以及原岩为长英质岩-黏土质杂砂岩的片麻岩类的相似度比较高,而与原岩为玄武岩类的角闪岩类相似度较低,成矿物质可能主要来源于同沉积时期的沉积物,后经区域变质作用而进一步富集成矿。对矿体直接顶底板围岩斜长角闪岩原岩恢复及构造环境判别结果显示,斜长角闪岩原岩应为弧后盆地玄武岩,暗示本区含铁建造沉积时的构造环境亦为弧后盆地。The Xincai iron deposit is located in the middle of the Wuyang-Huoqiu iron ore metallogenic belt in the southern margin of the North China Craton,the key part connecting Wuyang iron ore in the west and Huoqiu iron ore in the east.The main orebodies are stratiform or stratoid,occur in NeoarcheanTaiHua rock group metamorphic rocks.On the basis of study on geological characteristics of the iron deposits in Xincai area,by means of systematically analysis of major and trace element of ore and wall rocks of the Liancun iron deposit a typical ore deposit in Xincai area,the metallogenetic tectonic background was discussed.In the rare earth distribution patterns,the similarity between iron ore and quartzite(original rocks are sandstone or ferrosilicate sediments)and gneiss(original rock is the gneiss class of feldspathic rock-clay miscellaneous sandstone)is relatively high,but not similar to amphibolite(original rock is basaltic amphibole),suggesting that the ore-forming material may be mainly derived from sediments of the same sedimentary period.According to the original rock recovery and tectonic setting environment discrimination of plagioclase amphibole in the surrounding rock,the original rock of plagioclase amphibole should be basalt occur in back-arc basin,suggesting that the forming tectonic environment of iron bearing formation in this area was also in back-arc basin.

关 键 词：铁矿床 条带状铁建造 构造背景 河南新蔡 

分 类 号：P618.31[天文地球—矿床学]