摘要
河南省新蔡铁矿田练村铁矿床位于华北克拉通南缘,赋存于新古代太华群铁山庙组地层中。矿石类型主要为条带石英磁铁矿和角闪磁铁矿。文章根据铁矿石矿石类型、结构、构造特征及地球化学元素特征,探讨练村铁矿床成因。矿石中磁铁矿的FeOT含量90. 6%~93. 1%,平均91. 8%,平均值与磁铁矿FeOT的理论值(93. 1%)接近。矿石中主量元素为Fe_2OT_3,含量34. 8%~50. 7%,SiO_2含量46. 6%~57. 5%,其他主量元素除MgO、CaO较高外,TiO_2、Na_2O、K_2O、P_2O_5等含量均<0. 1%,表明该区磁铁矿为含杂质极少的纯磁铁矿,显示沉积变质成因磁铁矿特征。练村铁矿床矿石样品中,Al_2O_3、MgO+MnO、TiO_2含量较低,说明该区成岩成矿未受到碎屑物质的混染。矿石稀土元素特征具有轻稀土亏损、重稀土富集,具有现代海水高温热液混合作用特征。研究认为练村铁矿床成因是较少受到陆源碎屑物质混染的化学沉积,经过后期变质作用,属于BIF型铁矿。
The Liancun iron deposit in The Xincai iron field,is located at the southen margin of North China Craton,It is deposited in the rocks of the Tieshanmiao Fomation of the Neoarchaean Tahua Group.The main ore type are Band quartz magnetite ore and Homblende magnetite ore.Discuss on the genesis of the Liancu iron deposit according to the ore type,structutal and geochemical characteristics.FeO Tcontents of Liancun magnetite ore form 90.6%-93.1%,the average is 91.8%,these values are consistent with the theoretical FeO Tvalue of magnetite.MgO、CaO are higer,but TiO2、Na2O、K2O、P2O5 are very low（〈0.1%）,suggesting that they are nearly pure magnetite,and typical of the banded iron formations.Al2O3、MgO＋MnO、TiO2 are lower,the diagenesis and mineralization in this area are not subjected toclasticmaterials.The light rare-earth lossing and heavy rare-earth enridhmenting,Characteristics of modern seawater and hydrothermal fluids from mid-oceanic ridges.We conclude that the genesis ore deposits of Liancun iron deposit is BIF depite.
作者
涂恩照
戴帅军
王夏
TU En-zhao;DAI Shuai-jun;WANG Xia(No.4 Geology Team,Henan Provincial Nonferrous Metals Geological and Mineral Resources Bureau,Zhengzhou 450016)
出处
《矿产勘查》
2018年第5期887-893,共7页
Mineral Exploration
基金
中国地质调查局项目(编号:12120114035101)资助
关键词
条带状铁建造(BIF)
新蔡练村铁矿
地球化学特征
矿床成因
河南
band iron formations （BIF）
Xincai Liancun iron deposit
geochemical characteristics
genesis ore deposits
Henan
