O and Hf isotope data. Zircon O- and Hf-isotope constraints on the genesis and tectonic significance of Permian magmatism in Patagonia CastilloPaula FanningC. Mark PankhurstRobert J. HervéFrancisco RapelaCarlos W. 2017 Summary of the O and Hf isotope data from zircon spot analyses