苍峄铁矿带成矿控矿规律及成矿模式探讨

Study on Metallogenic Ore Controlling Law and Metallogenic Model of Cangyi Iron Deposit Belt

山东省苍峄地区铁矿资源丰富,是典型的"鞍山式"铁矿成矿区。先后发现和评价了多处大中型铁矿床。该文在介绍苍峄铁矿带成矿地质特征基础上,将其分为5个含矿带,矿体赋存于泰山岩群山草峪组中上部,严格受山草峪组地层控制,展布形态受太白向斜和石闫背斜两褶皱构造的控制,断层构造破坏了赋矿构造及矿体的连续性,间接控制了铁矿体的赋存和分布。原岩建造为基性火山岩-中酸性火山岩-粉砂岩-硅铁质建造,属火山活动间歇期成矿。分析认为成矿物质来源与海底火山活动密切相关,遭受后期变质作用后成矿物质富集,为沉积变质铁矿床产于以黑云变粒岩为主并夹有角闪质岩石等岩层的铁矿,铁矿沉积后,受后期强烈构造-热液改造叠加,矿体形态以似层状、透镜状为主。向斜构造是矿体富集保存的最佳构造模式,接近向斜核部矿体厚度增大,品位也有增高趋势。

Cangbo area in Shandong province is rich in iron ore resources.It is a typical"Anshan type"iron ore forming area.Several large and medium iron deposits have been discovered and evaluated successively.On the basis of introducing the metallogenic geological characteristics of Cangfu iron ore belt,it can be divided into five ore bearing belts.The ore bodies occur in the middle and upper part of Shancaoyu formation of Taishan group,which are strictly controlled by strata of Shancaoyu formation.The distribution pattern is controlled by two fold structures of Taibai syncline and Shiyan anticline.The fault structure destroys the continuity of ore hosting structure and ore body,and indirectly controls the occurrence and distribution of iron ore bodies.The protolith formation is basic volcanic rock intermediate acid volcanic rock siltstone ferrosiliceous formation,which belongs to volcanic intermittent mineralization.It is concluded that the source of ore forming materials is closely related to submarine volcanic activities.After the late metamorphism,the ore forming materials are enriched.The deposit is a sedimentary metamorphic iron ore deposit produced in an iron ore deposit with biotite granulite as the main rock layer and amphibolite as the main rock layer.After the iron deposit,it is superimposed by strong tectonic hydrothermal transformation in the later period,and the ore body is mainly layered and lenticular.Syncline structure is the best structural model for ore body enrichment and preservation.The thickness of ore body near the core of syncline increases,and the grade also tends to increase.