黔阳隘口基性超基性岩地球化学特征

GEOCHEMISTRY OF BASIC-ULTRABASIC ROCKS FROM AIKOU AREA IN THE WEST OF HUNAN PROVINCE

位于华南和扬子两大构造单元接合部位的隘口基性超基性岩及玄武岩，为ＬＲＥＥ富集型，并富含Ｒｂ、Ｓｒ、Ｋ、Ｔｉ、Ｚｒ、Ｕ、Ｔｈ、Ｔａ等大离子亲石元素和不相容元素，具有高的氧同位素组成δ１８Ｏ为９．５８％～１１．０６％，Ｉｓｒ为０．７０６２９４，它们是在稳定的陆壳受到交代作用影响的上地幔经部分熔融形成的。

Aikou basic-ultrabasic rocks and basalts,located in the combining part of South China and Yangtze tectonic units,are LREE-rich type and rich in large ionic lithophile and incompatible elements(e.g.Rb,Sr,K,Ti,Zr,U,Th,Ta etc.).The rocks are of high δ18O% and 87Sr/86Sr values(being 9.58～11.06 and 0.706294 respectively).The rocks' parental magma formed in the upper mantle which underwent partial melting and was influnced by metasomatism.