湘中锡矿山式锑矿稀土元素地球化学研究

湘中锡矿山式锑矿与硅化关系密切。稀土元素地球化学研究表明，存在着灰岩硅化和砂泥质岩硅化不同原岩类型的成矿围岩蚀变。硅化岩的稀土元素含量要比未蚀变原岩稍低，但是仍具有与原岩一致的相对关系，据此，可以恢复硅化岩原岩。硅化灰岩的稀土元素含量低，硅化砂岩（包括硅化泥质粉砂岩）相对较高。硅化灰岩的稀土元素配分型式有负Ｅｕ异常和负Ｃｅ异常；而硅化砂岩稀土元素配分型式类似原岩，只有负Ｅｕ异常，无Ｃｅ异常。辉锑矿稀土配分型式也区分出有Ｃｅ异常和无Ｃｅ异常的两种类型，反映成矿流体是否有对灰岩地层广泛强烈的硅化蚀变交代。

THE REE GEOCHEMICAL CHARACTERISTICS OF XIKUANGSHAN-TYPE ANTIMONY DEPOSITS IN CENTRAL PART OF HUNAN PROVINCE

The Xikuangshan type antimony deposit is the most important type of antimony deposit in China. It is intimate with silicification. REE geochemistry study shows that there are silicifications of limestone and sandstone . Both can be distinguished well by REE characteristics. REE gross of the silicified limestone is much lower than that of the silicified sandstone. REE chondrite normalized patterns are different also. The silicified limestone is negative abnormal in Ce, but the silicified sandstone normal. There are two types of antimonite. One is negative abnormal in Ce just the same as the silicified limestone and it can be explained that the ore forming fluid experienced silicification of limestone and be similar to limestone. Thus, this indicates that the silicification of limestone beneath or nearby is a good prospect to discover a blind antimony deposit. The other, no abnormal in Ce, only a bad prospect to discover a blind deposit.