ABSTRACT

We present new Sr, Nd, Hf and Pb isotope data for Early Miocene shoshonitic and high-K lavas dredged from seamounts in the South Fiji Basin, southwest Pacific Ocean. Our analyses provide a useful reference dataset for this distinctive compositional suite. The shoshonitic lavas formed in an intra-oceanic back-arc basin setting and are broadly coeval with nearby arc and back-arc basin lavas. Further work in the region will be needed before the tectonic implications of the shoshonitic and high-K lavas are fully understood.

中文翻译：

---

南斐济盆地早中新世钾玄质熔岩的 Sr、Nd、Hf 和 Pb 同位素地球化学：注

摘要

我们提供了新的 Sr、Nd、Hf 和 Pb 同位素数据，这些数据来自西南太平洋南斐济盆地海山中疏浚的早中新世钾玄质岩和高 K 熔岩。我们的分析为这个独特的组合套件提供了有用的参考数据集。钾玄质熔岩形成于大洋内的弧后盆地环境中，与附近的弧和弧后盆地熔岩大致同代。在充分了解磷玄质岩和高钾熔岩的构造意义之前，该地区还需要开展进一步的工作。