Lu-Hf and Sm-Nd isotope systems in zircon

East-derived strata in the Methow basin record rapid mid-Cretaceous uplift of the southern Coast Mountains batholith

“…In addition to the radioactive decay of 176 Lu to stable 176 Hf, fractionation during partial melting of the mantle leads to Hf-enriched partial melt and residual mantle depleted in Hf and enriched in Lu (Amelin et al 1999;Kinny and Maas 2003). Because zircon crystals easily incorporate Hf but not Lu, without additional 176 Lu to decay to 176 Hf, the ratio of 176 Hf to the stable isotope 177 Hf in the zircon essentially stays constant after formation of the zircon crystal.…”

“…Because zircon crystals easily incorporate Hf but not Lu, without additional 176 Lu to decay to 176 Hf, the ratio of 176 Hf to the stable isotope 177 Hf in the zircon essentially stays constant after formation of the zircon crystal. In contrast, the enrichment of 176 Lu in the residual mantle due to fractionation during partial melting means that the mantle's 176 Hf/ 177 Hf ratio increases with time as more 176 Lu decays to 176 Hf (e.g., Kinny and Maas 2003). The geochemical signature of the zircon crystal is described in terms of epsilon () units, where more positive Hf values indicate juvenile sources extracted from the mantle more recently and therefore record higher 176 Hf/ 177 Hf, and negative Hf values indicate evolved sources that were originally extracted from the mantle prior to significant fractionation, and therefore record lower 176 Hf/ 177 Hf.…”

Geochronology and geochemistry of igneous rocks in the Bailingshan area: Implications for the tectonic setting of late Paleozoic magmatism and iron skarn mineralization in the eastern Tianshan, NW China

“…In addition, elevated Y/Nb values of the tuffaceous dacite (3.14-6.79) ( Table 2) also point to a crustal (Y/Nb N 2) origin (Eby, 1992). The in-situ Hf isotopic analysis of zircons, combined with their U-Pb ages, provides a robust method to trace the source and petrogenesis of magmas, and to constrain the crustal evolution history (Woodhead et al, 2001;Kinny and Maas, 2003;F.Y. Wu et al, 2006;Kemp et al, 2007;Santosh et al, 2015).…”

“…Wu et al, 2006;Kemp et al, 2007;Santosh et al, 2015). Kinny and Maas (2003) have shown that negative ε Hf (t) values indicate source materials derived from partial melting of older crust and positive ε Hf (t) values indicate derivation from juvenile magmas. The zircon Hf isotope model ages represent the extraction time of source materials from the depleted mantle and the residence time in the crust .…”

Crustal Evolution of the Northeast Laurentian Margin and the Peri-Gondwanan Microcontinent Ganderia Prior to and During Closure of the Iapetus Ocean: Detrital Zircon U–Pb and Hf Isotope Evidence from Newfoundland

“…Hf isotope composition of detrital zircon coupled with U-Pb dating represents a powerful tool to assess continental growth and recycling processes. Fractionation of Hf, which occurs between zircon and co-precipitating phases during magma generation (Vervoort et al 1999;Kinny and Maas 2003;Scherer et al 2007), preserves a record of the Hf isotope ratio of the magma and the crust where the magma originated, and allows Hf isotope composition to be utilized as a geochemical fingerprint of the magmatic source. In particular, times of juvenile material addition to the continental crust and crustal recycling can be recognized.…”