辽宁宽甸黄椅山玄武岩中地幔岩捕虏体的REE 及 Sr、Nd 同位素地球化学

报道了黄椅山玄武岩中三类地幔岩捕虏体的 REE 丰度和 Sr、Nd 同位素组成。研究分析认为:尖晶石二辉橄榄岩是地幔岩经不同程度部分熔融的残留体;角闪石二辉橄榄岩系地幔交代作用的结果;石榴石二辉岩是在地幔条件下基性岩浆的分凝体。上述捕虏体均与寄主玄武岩无成因关系。地幔岩捕虏体的 Sm-Nd 计时获得741Ma 和78Ma 两条参考等时线,它们分别相当于晚元古代和晚中生代的地幔事件。

REE AND Sr,Nd ISOTOPE GEOCHEMISTRY OF THE MANTLE XENOLITES FROM HUANGYISHAN BASALT,KUANDIAN, LIAONING PROVINCE

REE contents, Sr and Nd isotopic compositions were measured on three types of mantle xinoliths from Huangyishan basalt. From the geochemical information it is believed that the Iherzolite xinoliths are the residues of the pyrolite after different degrees of partial melting, the amphibole-bearing Iherzolite came from the mantle after metasomatism and the garnet pyro-xenite was crystallized from basalitic magma at the mantle conditions. No original relation was found between the xenoliths and the host basalt. The mantle events of 741 Ma and 78 Ma showed by the Sm-Nd reference isochron of these xenolith samples are in the ages consistent with the Jinning and Yanshanian movements on China continent, respectively.