阴山地区印支期碱性侵入岩岩石地球化学特征

通过系统的矿物学、岩石学、地球化学研究，确立了阴山地区印支期碱性岩在空间上分为南北两条近东西走向的岩带。南带以霓辉正长岩为主，北带以碱性正长岩为主。南北两带岩体均富集轻稀土元素、大离子亲石元素和高场强元素，而Cr、Ni等相容元素含量很低。结合Nd、Sr、Pb同位素特征，认为该地区印支期碱性岩源自富集地幔，并受到不同程度的地壳物质混染。

Petrogeochemical Characteristics of Indosinian Alkaline Intrusions in YinshanArea

Systematic research methods including mineralogy, petrology and geochemistry were used to study the Indosinian alkaline intrusions in Yinshan area. It is concluded that the Indosinian alkaline intrusions in Yinshan area make up two nearly EW_striking rock belts lying in the north and in the south respectively. The southern belt is mainly composed of augite_aegirine syenites, whereas the northern one consists mainly of alkali_syenite. Both belts are enriched in LREE, large_ion lithophile elements and high charge density elements. However, the content of compatible elements such as Cr and Ni are very low. Combined with the isotopic characteristics of Nd, Sr, and Pb, the authors have drawn the conclusion that the Indosinian alkaline intrusions of Yinshan area were generated from the enriched mantal, and during their invasion they were contaminated by crustal materials in different degrees.