鲁西郗山—关帝庙地区碱性杂岩体微量元素地球化学特征及其意义OA

Based on detailed petrographic observations,characteristics of trace elements and rare earth ele-ments in rocks and minerals have been analyzed and studied.It is indicated that Xishan—Guandimiao alka-line complex is enriched in Ba,U,Pb,Th,La,Ce,while depleted in Nb,Ta,Zr and Hf.Nb＞Ta.It is enriched in light rare earth elements and depleted in heavy rare earth elements.The differentiation of light and heavy rare earth elements is significant,and there are no obvious abnormalities in Ce and Eu.The trace element distribution curves of Guandimiao and Xishan rocks are similar.It is indicated that the two rock masses are homologous magmas.It is speculated that the diagenetic material initially comes from the product of partial melting of lithospheric mantle,its parent magma is carbonate silicate rock melt.Mag-matic and hydrothermal apatite have been found in Xishan rock mass.It is indicated that the magma has experienced strong crystallization differentiation and a certain degree of mixing.A large amount of light rare earth minerals are formed during the hydrothermal stage.