Sr, Nd, Hf and Pb isotope geochemistry of Early Miocene shoshonitic lavas from the South Fiji Basin: note

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.

Automated summary

The study presents new isotope data for Early Miocene seamount lavas and suggests they formed in an intra-oceanic back-arc basin setting. The lavas are broadly contemporaneous with nearby arc and back-arc basin lavas, highlighting the need for further research to fully understand their tectonic implications.