山东省韩旺条带状铁矿床地质特征及其成矿地质条件分析

Analysis on Geological Characteristics and Oreforming Conditions of Hanwang Banded Iron Deposit in Shandong Province

摘要:

山东省沂源县韩旺铁矿是华北克拉通一大型条带状铁矿床，铁矿层赋存于新太古代泰山岩群雁翎关组上部的变质岩系中。矿体规模较大，断续延伸近8000m，单矿层厚度一般1～25m。矿体总体呈单斜层状产出，矿石为硅质和铁质相间排列构成的条纹—条带状构造。含矿岩性主要为含磁铁斜长角闪片岩、含磁铁石英角闪片岩及片麻岩类，原岩属于中基性的火山岩和火山沉积岩类。结合近些年来国内外学者在研究前寒武纪BIF铁矿年代学、同位素地球化学与成矿作用方面取得的最新进展，认为韩旺铁矿沉积成矿时代为~2.6Ga，矿床形成于海洋化学沉积环境，成矿物质来源具有明显的火山物质贡献特征，矿床的形成与华北地区太古宙克拉通化形成的稳定沉积环境以及微生物的参与是密不可分的。

Abstract:

Hanwang iron deposit in Yiyuan county of Shandong province is a large banded iron deposit in North China Craton. Its ore bodies occur in the metamorphic rocks of upper Yanlingguan formation of NeoArchaean Taishan Group. The ore bodies are generally layered with thickness of 1~25m, which can extend over 8000m intermittently. The iron ores are characterized by banded texture with alternating siliceous and ferruginous. The orebearing rocks are named as magnetiteplagioclase amphibole schist, magnetitequartz amphibole schist and their gneisses. Its original rock belongs to basic volcanic rocks and volcanic sedimentary rocks. Combining with advanced development gained in chronology, isotope geochemistry and metallogenesis of Precambrian BIF iron deposit in recent years by domestic and overseas scholars. It is regarded that Hanwang iron deposit was formed during 2.6Ga in marine chemical sedimentary environment. Its ore materials were associated with volcanic hydrothermal solution. It is concluded that stable sedimentary environments resulting from NeoArchaean cratonization of North China and anaerobe involving were all indispensable during the formation of the deposit.