安徽宁芜盆地杨庄玢岩型铁矿地质特征及找矿方向

Geological characteristics and prospecting direction for porphyrite type iron deposit in Yangzhuang,Ningwu Basin,Anhui Province

安徽省杨庄铁矿是近年来在钟姑山矿田新发现的又一大型铁矿床,位于宁芜盆地南段钟姑山复背斜的次级褶皱向阳向斜构造的北转折端,矿体主要赋存于徐家山组与闪长(玢)岩的内外接触带、三叠系徐家山组地层中及闪长(玢)岩内部,整体走向NW,倾向SW,局部倾向SE,倾角变化较大,总体呈似层状、层状、透镜状产出,局部具分支复合、膨大收缩,尖灭再现等特征,矿石以磁铁矿为主,次为(假象)赤铁矿矿石,矿石结构以他形-半自形微细粒结构为主,矿石构造以浸染状-稠密浸染状构造为主,矿床成因应属气化-热液交代为主的充填-接触交代型铁矿床,明显有别于已有的凤凰山(白象山)式、姑山式铁矿床,应为新亚式"杨庄式玢岩铁矿"。该新亚式的提出,丰富了"玢岩铁矿"模式。

Yangzhuang iron deposit is another large iron deposit newly discovered in the Zhonggushan ore field in recent years.It is located at the north turning point of the sunward syncline of the secondary fold in the Zhonggushan anticline in the southern segment of the Ningwu basin,the ore bodies are mainly located in the contact zone between Xujiashan formation and Diorite(porphyrite),in the Triassic Xujiashan formation and in the Diorite(porphyrite),the ore is mainly magnetite,secondly hematite(illusory),secondly hematite,and the ore structure is mainly other-shaped and semi-self-shaped fine grain structure,the ore structure is mainly disseminated-dense disseminated structure,and the Genesis of the deposit belongs to the filling-contact metasomatic type of iron deposit dominated by gasification-hydrothermal metasomatism,which is obviously different from the existing Lantau Peak(Baixiangshan)type and Gushan type iron deposits,should be the new Asian"Yangzhuang porphyrite iron ore.".The emergence of this new Asian style enriched the"porphyry iron ore"model.