安徽霍邱李老庄铁矿—菱镁矿床地质特征及成因类型

Geological characteristics and genetic type of Lilaozhuang iron-magnesite deposits in Huoqiu county,Anhui Province

霍邱铁矿田位于华北地台南缘,处于北淮阳山字型构造脊柱部位。李老庄铁矿—菱镁矿床置于霍邱铁矿田中部。该矿床主要产于上太古界霍邱群变质岩系中,矿体赋存于富镁碳酸盐中,矿石类型可以分为菱镁矿磁铁矿石和蛇纹石磁铁矿石,各占25%。成矿物质来源于这些变质岩系的多层、分散的含铁建造矿源层中。依据矿床地质特征,结合矿石同位素地质和测年结果,李老庄铁矿—菱镁矿铁矿床是晚太古代海相火山—沉积变质型矿床。

Huoqiu iron ore field,Anhui Province,is located in the south margin of North China platform, which is situated at the backbone of the epsilon-type structure of Beihuaiyang tectonic belt. Li- laozhuang iron-magnesite deposit lies in the center of Huoqiu iron ore field. The iron-magnesite ore deposit is occurred in the metamorphic rock series of the Archean Huoqiu group. The ores are hosted in the Mg-rich carbonate rocks. The ore types can be divided into magnesite-magnetite type and chrysotile-magnetite type,which are occupied 25% respectively . The major ore forming materials came from the multi-bedded and dispersed ore-bearing strata in the metamorphic rock series. According to the geological characteristics of the deposit and ore isotope geological dating, the author believes that Lilaozhuang iron-magnesite deposit can be considered as a late Archean marine volcanic sedimentary-metamorphic type deposit.