广东麒麟绿钙闪石巨晶的地球化学特征

GEOCHEMISTRY OF HASTINGSITE MEGACRYSTS FROM QILIN, GUANGDONG

本文对罕见的幔源绿钙闪石巨晶进行了综合的地球化学分析。主要元素、稀土微量元素和Sr、Nd同位素的特征表明:绿钙闪石巨晶是碱性玄武岩浆在地幔条件下的结晶产物;相对于寄主玄武岩,绿钙闪石巨晶均属捕虏晶;它们与共存的橄榄岩包体无成因联系,其形成可能与共存的黑色包体有关。

An integrated geochemical analysis has been made on mantle-derived hastingsite megacrysts, which are rare in the world. Their major element, REE and Sr and Nd isotope geochemical features indicate that the hastingsite megacrysts are the product of crystallization of alkali basaltic magma in the mantle. They are xenocrysts relative to their host-basalt. These megacrysts have no genetic relation with their coexisting peridotite inclusions, but are probably related to their coexisting black inclusions.