山东临沂东小山地区煌斑岩地球化学特征及其对成矿的启示  

Geochemical characteristics and indication for mineralization of Dongxiaoshan lamprophyre in Linyi City,Shandong Province

作　　者：高存山 褚志远 张勇 王玉峰 GAO Cun-shan;CHU Zhi-yuan;ZHANG Yong;WANG Yu-feng(The 7th Institute of Geology and Mineral Exploration of Shandong Province,Linyi 276600,China;Diamond Minerogenesis and Exploration Key Laboratory,Shandong Provincial Bureau of Geology and Mineral Resources,Linyi 276600,China)

机构地区：[1]山东省第七地质矿产勘查院,临沂276600 [2]山东省地矿局金刚石成矿机理与探测重点实验室,临沂276600

出　　处：《华东地质》2020年第3期271-278,共8页East China Geology

基　　金：山东省自然资源厅“山东省费县东小山地区金刚石普查(编号:鲁国土资字[2016]328号)”;山东省科学技术厅“金刚石深部找矿理论与方法(编号:2017CXGC1607)”项目联合资助。

摘　　要：山东临沂东小山地区煌斑岩属于弱铝超钾质煌斑岩,高Ba、Th、P,轻稀土元素富集,轻、重稀土元素分馏明显,表明煌斑岩在后期侵位过程中受到了地壳物质的混染。煌斑岩富集大离子亲石元素和高场强元素,反映岩浆主要来源于富集型地幔,进一步说明其源区受到了壳源物质的混染。通过人工重砂方法选获了2颗铬透辉石,计算其形成温度和压力分别为1180℃和5.8 Gpa,对应的深度约为180 km,与金刚石的形成深度一致。The lamprophyre in Dongxiaoshan area of Linyi City,Shandong Province,belongs to the weak aluminum ultra-potassic type with high Ba,Th and P,enrichment of LREEs and distinct fractionation between LREEs and HREEs,indicating the lamprophyre is contaminated by crustal materials during the late emplacement.The lamprophyre rich in LILEs and HFSEs shows that the magma mainly comes from the enriched mantle,further revealing its source area is contaminated by the crustal materials.Two chrome diopsides are selected by artificial heavy concentrate method to calculate the formation temperature of 1180℃and pressure of 5.8 Gpa respectively,with the corresponding depth of about 180 km,which is consistent with the formation depth of diamond.

关 键 词：煌斑岩 地球化学特征 重砂矿物 成岩时代 东小山地区 山东临沂 

分 类 号：P619.241[天文地球—矿床学] P581[天文地球—地质学]