transitional series meaning in English

过渡岩系

The low - ti series show variable degrees of nb - ta depletion in primitive mantle - normalized spidergrams with slightly enriched to depleted nd isotopic compositions , whereas the transitional series exhibit similar geochemical features to emii - oib and have transitional characteristics between the high - ti and low - ti rocks . all three groups show no continuous shift in major and trace elements and cannot be regarded as different phases during magma differentiation process . on the basis of normalization to mgo = 8 % , the high - ti diabases have the lowest sig , nag and highest tig and peg
通过详细的岩石学和元素-同位素地球化学研究，这些岩石具有各自不同的地球化学特征，其中高ti系列的低la nb 、 zr nb比值和亏损的nd同位素组成显示其类似于oib的特征，过渡ti系列则显示出emii - oib的特征，而低ti系列则高la nb 、 zr nb比值和变化的nd同位素组成显示出一定比例的富集岩石圈地幔或地壳物质的参与。