河南舞阳铁矿赵案庄组含矿层的岩石矿物组合特征及成矿作用

Rock and mineral assemblage features and metallogenesis of ore-bearing layers in the Zhaoanzhuang Formation of the Wuyang iron mine,Henan Province

赵案庄型铁矿是河南舞阳铁矿床中重要的铁矿类型。通过采取矿区含矿岩层岩性标本,运用岩石学、岩石成岩理论、变质相的新理论对各种岩石标本进行偏光镜下的岩矿鉴定,分析各种岩石的矿物组合、岩石的结构构造、矿物的生成顺序、矿物的结晶力和变晶相系,确定不同含矿层的岩石组合,推断其变质程度,初步划分变质相;同时分析成矿组分在不同矿物之间的转换过程,建立初步成矿模式。总结了赵案庄组含矿层的岩石矿物组合特征,厘定了研究区含矿变质岩系的变质级、变质相系,初步分析各类变质岩中矿物组合在变质作用过程中的变化,确定区内各类变质岩的原岩类型;同时分析了成矿组分铁质来源、铁质在原岩的成岩作用及随后的区域变质作用过程的变化,不同矿质来源与矿石特征、矿体产出形态的关系,为深部找矿提供参考。

Zhaoanzhuang-type iron deposits are an important type of the Wuyang iron deposits in Henan Province. This work collected rock samples from ore-bearing intervals in this deposit, and carried out microscopic identification with the theory of petrology, rock dia- genesis and the new theory of metamorphic facies. We analyzed the mineral assemblages, rock textures and structures, mineral forma- tion sequence, mineral crystallization force and crystalloblastic facies series, and rock assemblages of different ore-bearing layers, and inferred their metamorphic degree and preliminarily divided the metamorphic facies. The transition process of ore-forming composition a- mong different minerals was determined, and a preliminary model was established. We summarized the rock and mineral assemblages of ore-beating layers in the Zhaoanzhuang Formation, the metamorphic grade and metamorphic facies series of ore-beating metamorphic rock series in this area, preliminarily analyzed the changes of mineral assemblage of various metamorphic rocks in metamorphism, and analyzed the original rock types of various types of metamorphic rocks in this area. In addition, we determined the the original source of ore-forming iron components, the role of iron during original rock diagenesis, the iron changes in later regional metamorphism, and the relationship of different sources of ore materials with ore characteristics and ore body occurrence shape. This study will be of some guid- ing significance for the deep prospecting of this area.