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本研究首次报道了早白垩世济南辉长岩中橄榄石斑晶捕获的熔体包裹体的研究结果。济南辉长岩中橄榄石的Fo(60.3~74.6),Mn(2500~3500μg/g),Ni(70~1349μg/g),Fe/Mn比值(61.2~83.5),与源区母岩为纯的橄榄岩形成的熔体结晶出的橄榄石性质不同,可能与源区存在辉石岩的贡献有关。橄榄石中熔体包裹体主量元素具有较大的变化范围。熔体包裹体成分的标准矿物计算(CIPW)表明,MgO>10%的熔体包裹体为含有霞石和橄榄石标准矿物分子的硅不饱和熔体,Mg O<10%时为含石英标准矿物分子的硅饱和熔体。橄榄石中包裹有辉石和斜长石,说明岩浆演化过程应该处于开放环境。熔体包裹体的(~208Pb/~206Pb)i和(~207Pb/~206Pb)i与MgO具有良好的负相关关系,与SiO_2具有良好的正相关关系,以及熔体包裹体具有较高的SiO_2特征表明岩浆演化过程中可能有下地壳长英质组分的加入。熔体包裹体的Pb同位素落在EMI附近并向EMII延伸,其源区可能有EMI和EMII的贡献,熔体包裹体的主量元素成分说明其源区母岩可能有橄榄岩和辉石岩的贡献。
This study reports for the first time the results of melt inclusions captured by olivine phenocrysts in the Early Cretaceous gabbros from Jinan. The content of Fe (60.3 ~ 74.6), Mn (2500 ~ 3500μg / g), Ni (70 ~ 1349μg / g) and Fe / Mn Peridotites form different melts that crystallize out of olivine, which may be related to the presence of pyroxene in the source area. The main elements of olivine melt inclusions have a larger range of variation. The standard mineral calculation (CIPW) of melt inclusions shows that the melt inclusions with MgO> 10% are Si-unsaturated melts containing nepheline and olivine standard mineral molecules, MgO <10% Molecule silicon saturated melt. Olivine wrapped pyroxene and plagioclase, indicating that the evolution of the magma should be in an open environment. The melt inclusions (~ 208Pb / ~ 206Pb) i and (~ 207Pb / ~ 206Pb) i have a good negative correlation with MgO and have a good positive correlation with SiO_2. The melt inclusions have high SiO_2 The characteristics indicate that there may be the addition of lower crustal quartz in the magmatic evolution. The Pb isotopes of melt inclusions fall near EMI and extend toward EMII. The source regions may have the contribution of EMI and EMII. The major element composition of melt inclusions indicates that the source rocks may contain peridotites and pyroxenites Contributions.