北大别变质杂岩的基本组分为一套成分相当于 Ｔ Ｔ Ｇ 岩套的灰色片麻岩。岩石化学成分中 Ｓｉ Ｏ２含量约为４７％ ～７９％ 。而且随着 Ｓｉ Ｏ２ 含量的增加， Ｔｉ Ｏ２ 、 Ａｌ２ Ｏ３ 、 Ｍｇ Ｏ、 Ｃａ Ｏ 和 Ｆｅ Ｏ 的含量相应下降， 这表明从英云闪长岩质片麻岩到奥长花岗岩质或花岗岩质片麻岩具岩浆成因， 是角闪石和斜长石的分离作用控制下岩浆分异的产物。岩石的稀土元素总量较低，轻重稀土分馏较弱， 近于平行的稀土元素配分曲线表明所有岩石具有同成因的亲缘关系。岩石富集大离子亲石元素， 亏损高场强元素和 Ｎｂ。偏基性的片麻岩较花岗质片麻岩更富集 Ｃｓ、 Ｂａ，、 Ｒｂ、 Ｓｒ和较少亏损 Ｎｂ 和 Ｔｉ。随着 Ｓｉ Ｏ２ 含量增加， Ｎｂ 亏损加大， Ｓｒ的富集程度减小， 过渡族金属元素 Ｔｉ强烈亏损， 表明岩浆中发生了镁铁矿物和斜长石的分离。花岗质片麻岩表现出岛弧花岗岩所具有的 Ｆｅ Ｏ、 Ｍｇ Ｏ、 Ｃａ Ｏ 含量低和 Ｆｅ Ｏ ／ （ Ｆｅ Ｏ＋ Ｍｇ Ｏ） 比值低的特征。亏损 Ｎｂ 和 Ｙ 的性质同样证明了他们属于火山弧花岗岩。在 Ｈｆ／３ Ｔｈ Ｔａ （ Ｎｂ） 判别图上所有岩石的投影点均落到岛弧钙碱性岩系的范围。主元素和微量元素的性质证明北大别的灰? The basic component of the North Dabie metamorphic complex is a set of gray gneisses with the composition of T T G mantle. Si O2 content of rock chemistry is about 47% ~ 79%. And with the increase of Si O2 content, the contents of Ti O2, Al2 O3, Mg O, Ca O and Fe O decrease correspondingly, which indicates that from the dacite gneiss to the dolomite or granite flax The magmatic origin of the rock is the product of magma differentiation controlled by the separation of amphibole and plagioclase. The total amount of rare earth elements in rocks is lower, and the light and heavy rare earth fractions are weaker. The near-parallel rare earth elements distribution curve shows that all rocks have the same genetic relationship. The rocks are enriched in large ion lithophile elements, depleted in high field strength elements and Nb. The biotite gneisses are more enriched in Cs, Ba, Rb, Sr and less depleted in Nb and Ti than the granitic gneisses. With the increase of Si O2 content, the loss of Nb increases and the enrichment of Sr decreases, and Ti, a metal element of the transitional family, is strongly depleted, indicating the separation of the mafic minerals and plagioclase from the magma. The granitic gneisses show the characteristics of low Fe O, MgO, CaO and low Fe O  / (Fe O  + Mg O) ratios of island arc granites. The loss of the properties of Nb and Y also proves that they belong to volcanic arc granite. The projection points of all rocks on the Hf / 3-Th-Ta (Nb) discriminant map all fall into the range of island arc calc-alkaline rocks. The nature of the main elements and trace elements prove North Dabie gray?