鄂东南矿集区程潮大型矽卡岩铁矿的花岗质岩与成矿关系探讨

The relationship between granitoids and mineralization of the Chengchao large-size skarn iron deposit in southeastern Hubei ore concentration area

程潮铁矿床位于鄂东南矿集区鄂城岩体南缘,矿体主要产于花岗质岩与大理岩或花岗质岩与闪长质岩的接触带附近。矿区矽卡岩和花岗质岩与矿体的接触关系密切。稀土元素分析结果表明:石榴子石、绿帘石和磁铁矿矿石的稀土元素配分模式具有右倾、轻稀土富集、Eu正异常和Ce无明显异常的特点,显示它们具有相同的来源,并且是在一种高温、高氧逸度、Eu较富集的流体环境中形成的;花岗质岩与矽卡岩、矿体在稀土元素组成特征方面具有相似性,暗示它们具有成因联系。结合地质特征和稀土元素化学特征可知,程潮铁矿的花岗质岩与矽卡岩和矿体在时间、空间和成因上都有着密切的联系。

Located on the southern margin of Echeng batholith in the southeastern Hubei ore concentration area,.the Chengchao iron deposit is the largest skarn iron deposit in the Middle–Lower Yangtze River Valley metallogenic belt.The ore deposit occurs along the contact between granitoids and carbonates or between granitoids and diorites.Ore bodies,granitoids and skarns have close contact relationships.REE analyses show that the chondrite-normalized REE patterns of garnets,epidote and magnetite ores in the Chengchao iron deposit are similar to each other and enriched in LREE（light REE） with Eu positive anomaly and without Ce anomaly,implying that they were formed in an oxidation environment by magmatic fluids characterized by high temperature and richness of Eu.The REE characteristics of granitoids,skarns and ores indicate their close genetic relationships.Geological and REE geochemical features show that granitoids,skarns and ore bodies are closely related to each other in time,space and genesis.