广东大沟谷钠长石岩地球化学特征及成因研究

粤西大沟谷一带钢长石岩主要以层状、透镜状及脉状产于震旦系乐昌峡群变质片岩中，具块状及条带状构造，是大沟谷金矿的主要赋矿岩石。钠长石岩富Na、St、Al、Mg、Mn、K，在微量元素方面富An、As、Sn、B、Cu、Ni、Co、Ph、Zn，稀土元素的含量较低，配分模式为平缓右倾曲线。矿物组合及铁白云石碳、氧同位素组成特征与秦岭地区热水沉积钠长石岩的基本相同。据大沟谷钢长石岩的地质地球化学特征认为钠长石岩是热水沉积的产物。

CHARACTERISTICS AND GENESIS OF THE DAGOUGU ALBITITE IN WEST GUANGDONG

The Dagougu gold-bearing albitite, which is characterized by bedding and massive struc-ture, is mainly stratiform and 1enticular in shape, and also occurs as veins in the Late Proterozoicschist. The albitite is characterized by enrichment of Na2O and SiO2 as well as trace elements suchas Au, As Sb,B and depletion of MgO, MnO,K,O and trace elements which include Cu, Ni,Co,Pband Zn. The gold-bearing albitite has a lower content of rare-earth elements and its REE patternsare flat with negative Eu-anomalies- The paragenetic association of minerals and the range of theC,O isotopic values of the Dagougu albitite are similar to those in the Qinling region of China,which is considered to be formed by hot water deposition. On the basis of the geological-geochemi-cal features of the Dagougu albitite, it could be concluded that the Dagougu albitite is of hot-watersedimentary origin.