Abstract GNS Science is New Zealand's geological survey with an applied earth science research focus yet without traditional government department accountabilities. As one of New Zealand's Crown Research Institutes established in 1992, GNS Science is owned by the New Zealand Government but has higher levels of self-determination, fiscal independence and impartiality than a government department. Securing competitive research funding and commissioned research is a business imperative and because of this the institute is able to respond and adapt to changing societal expectations. GNS Science can also influence outcomes based on its discretionary research investment. New Zealand's geological setting astride an active plate boundary attracts many international partners endeavouring to better understand geological processes in an accessible and logistically well-resourced natural laboratory. Partnerships like these substantially increase technological and financial resources and these enable diverse and often ambitious projects.

Abstract U–Th–Pb dated zircons from Western Province paragneisses and orthogneisses were analysed for rare earth element (REE) concentrations, as well as oxygen and hafnium isotopic compositions. Experiments performed in situ using a sensitive high-resolution ion microprobe (SHRIMP) and laser ablation multicollection inductively coupled plasma mass spectrometer (LA-MC-ICPMS) allow better understanding of crustal growth on the Zealandia margin of Gondwana from the micron scale. Paragneiss zircons were probably derived from similar sources to those that supplied the regional Ordovician Greenland Group and correlative southern Australian and Antarctic meta-sedimentary rocks. Detrital zircon grains record variable REE patterns relating to magmatic and metamorphic crystallization processes operating prior to and following Ordovician deposition. δ 18 O and ɛ Hf(T) values trace major phases of juvenile crust formation and subsequent reworking in provenance sources, signifying an increase in the recycling of compositionally diverse, evolved crustal materials through time. Orthogneiss zircons relate to two episodes of magmatism that record similar REE concentration patterns. Devonian zircons have elevated δ 18 O and un-radiogenic ɛ Hf(T) ; Cretaceous zircons record more primitive δ 18 O and radiogenic ɛ Hf(T) . Both orthogneiss suites require thorough mixing of mantle-derived magmas with a component of Greenland Group rocks. The relative proportion of this crustal contamination is c. 20–50% for the Devonian orthogneisses and c. 10–40% for the Cretaceous orthogneisses. Orthogneiss protolith materials were largely hybridized prior to and during zircon crystallization, suggesting that plutonic assembly occurred over restricted structural levels. These results demonstrate the ability of zircon to retain detailed petrogenetic information through amphibolite-facies metamorphism with excellent fidelity. Supplementary material: Analytical methods and data are available at www.geolsoc.org.uk/SUP18755