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对33件采自东太平洋海隆(EPR)13°N附近的玄武岩和火山玻璃样品进行了微量元素分析,以探讨该区域玄武岩的演化过程和物质来源。测试分析结果显示所有样品的微量元素含量比值m(Tb)/m(Lu)(1.74~2.03),m(Sm)/m(Nd)(0.29~0.35)和m(Nd)/m(Y)(0.32~0.48)存在不能忽略的变化,表明它们可能受到了非均一质地幔来源的影响。m(La)/m(Nb),m(La)/m(Sm)和m(La)的线性相关性辨别结果,以及稀土元素分布型式图表现的元素分布特征等均表明东太平洋海隆13°N附近的洋中脊玄武岩可能来自不同的端元组分,也证明研究区域内的玄武岩除N-MORB(常规型MORB)外,还有E-MORB(富集型MORB)。此外,玄武岩m(Ce)/m(Pb)和m(Ce),m(Nb)/m(U)和m(Nb),以及m(Nb)/m(La)和m(La)线性相关性,均显示了这些微量元素比值和微量元素含量的正相关趋势,这可能与双组分地幔熔融有关。m(Nb)/m(Th)和m(Th)线性相关性显示出负相关,显示该区域玄武岩的地幔来源组成可能受到了富集组分的影响。分析显示,样品的Nb*值均大于1,而大部分样品的Ta*值大于1,这表示大部分玄武岩的来源很可能是从俯冲区域循环的物质。
Thirty-three basaltic and volcanic glass samples from the East Pacific Rise Sea (EPR) at 13 ° N were analyzed for trace elements to investigate the evolution of basalts and the source of their material. The results of the test and analysis showed that the ratio of trace elements (m / Sm) / m (Nd) (0.29-0.35) and m (Nd) / m (0.32-0.48), which can not be neglected, indicate that they may be affected by the heterogeneous mantle source. The results of the linear correlation between m (La) / m (Nb), m (La) / m (Sm) and m (La) and the elemental distribution characteristics of the RE patterns indicate that the East Pacific Rift 13 ° The mid-ocean ridge basalts near N may originate from different endmember compositions and also demonstrate that basalts in the studied area have E-MORB (enriched MORB) in addition to N-MORB (conventional MORB). In addition, basalts m (Ce) / m (Pb) and m (Ce), m (Nb) / m (U) and m (Nb), and m Both of them show a positive correlation trend between these trace element contents and trace element contents, which may be related to the two-component mantle melting. The linear correlation between m (Nb) / m (Th) and m (Th) shows a negative correlation, indicating that the mantle source composition of basalts in this region may be affected by enrichment components. The analysis shows that the Nb * values of the samples are all greater than 1, whereas the Ta * values of most of the samples are greater than 1. This indicates that most of the basalt sources are likely to be substances that circulate from the subducted areas.