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山东临朐新生代玄武岩携带有较多的单斜辉石晶体,这些单斜辉石中发现存在大量玻璃质熔体包裹体.玻璃质熔体包裹体形状极不规则,大小多在10~50μm之间,并与低镁橄榄石、拉长石和富钙钾长石共生.原位主、微量元素分析表明玻璃质熔体包裹体富碱(Na2O+K2O>10%),高硅(>54%)、钙、铁(>4%,质量分数,下同),贫镁(Mg#<20),富集轻稀土元素((Ce/Yb)cn=11.6~16.4),并具有明显的Eu正异常(Eu/Eu*>2),即为类似响岩质组成.单斜辉石晶体和玻璃质熔体包裹体及其共生矿物的组成特征说明这些熔体包裹体是寄主玄武岩携带前捕获的外来熔体.该熔体包裹体的发现为进一步探讨华北东南部中生代岩石圈地幔的演化过程提供了另一个新的途径.
In the Linqu Cenozoic basalts in Shandong Province, there are many clinopyroxene crystals, and many clinoptilolite inclusions are found in these clinopyroxenes. The vitrified melt inclusions are extremely irregular in shape and mostly have a size of 10-50 μm Intergrowth with low-forsterite, labradorite and calcium-rich feldspar.The in situ primary and trace element analyzes show that the vitreous melt inclusions are rich in alkali (Na2O + K2O> 10%), high silica (> 54% (Ce / Yb) cn = 11.6 ~ 16.4), with obvious Eu (superscript +), Eu The anomaly (Eu / Eu *> 2) is similar to the anabolic composition.The compositional characteristics of clinopyroxene and glassy melt inclusions and their intergrowth minerals indicate that these melt inclusions were captured before the host basalt was carried The discovery of this melt inclusions provides another new approach to further explore the Mesozoic lithospheric mantle evolution in the southeastern North China.