Sr-Pb-Nd-Hf isotope data for the Taupo Volcanic Zone and Hikurangi margin, New Zealand

The Taupo Volcanic Zone is dominated by silicic magmatism, usually attributed to intense AFC processing within the crust. However, isotopic data shows a sub-linear behaviour in all isotope systems here presented and instead suggest that they are the result of a binary mixing between two endmembers: the subarc mantle wedge and a crustal material. This mixture is inconsistent with intense crustal assimilation due to variations seen in the isotopic characteristics of the New Zealand crust. Instead, this mixing may be occurring subcrustally by interactions between tectonically eroded forearc material and the subarc mantle wedge. International Ocean Discovery Program (IODP) Expedition 372B/375 drilled into the Hikurangi margin in a perpendicular transect, greatly increasing the information and availability of material from the subducting plate and accretionary prism. Here we report Sr-Pb-Nd-Hf data for samples from this expedition along with TVZ samples.