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对华北东部昌乐-临朐新生代玄武岩中的单斜辉石巨晶及其所携带的橄榄岩-辉石岩捕掳体进行了系统的岩石地球化学和稀有气体同位素研究,旨在为华北东部岩石圈地幔的演化提供制约.稀有气体同位素研究结果显示,与寄主玄武岩有成因联系的单斜辉石巨晶、二辉石岩和纯橄岩都具有比MORB略低的He同位素比值(分别为7.0~7.7,7.4和7.0~7.7 Ra)和接近大气特征的Ar同位素比值;来自岩石圈地幔碎片的二辉橄榄岩和异剥橄榄岩的橄榄石也具有同样特征的He(7.0~7.6 Ra)和Ar同位素比值,并且与其部分熔融程度无关,指示这个地区的岩石圈地幔受到过来自地壳衍生熔体的交代.二辉橄榄岩和异剥橄榄岩中单斜辉石和斜方辉石具有较低的He含量、3He/4He比值(2.3~7.1 Ra),结合样品岩石学及前人地球化学研究成果,推测交代华北克拉通之下新生代岩石圈地幔的熔体可能来自于太平洋板块的俯冲.
Systematical lithogeochemical and rare gas isotopic studies of the clinopyroxene monolith in the Changle-Linqu Cenozoic basalts in eastern North China and their entrained peridotite-pyroxenite entrapment are carried out to study the lithospheric Mantle evolution provided constraints.The results of Rare-gas isotope studies show that the clinopyroxene megacrysts, diopside rocks and dunites that are genetically linked to host basalts have slightly lower He isotope ratios than MORB (7.0-7.7, 7.4 and 7.0-7.7 Ra) and Ar isotopic ratios close to atmospheric characteristics. Olivites from lurking lithospheric mantle fragments and olivines from dextral peridotites also have similar characteristics of He (7.0-7.6 Ra) and Ar isotopic ratios , And has nothing to do with the degree of partial melting, indicating that the lithospheric mantle in this area has been interpreted by the melt derived from the crust.Herolite and orthopyroxene in the lherzolites and dextral peridotites have lower He content, 3He / 4He ratio (2.3 ~ 7.1 Ra), combined with the sample petrology and previous research results of geochemistry, it is inferred that the melt of the Cenozoic lithospheric mantle beneath the North China Craton may come from the Pacific plate Dive