Fig. 3: Crystallization conditions and trace-element composition of zircons.
From: Large-scale crustal growth driven by LIP magmatism during the Paleoproterozoic
A, B Plot of chondrite-normalized90 rare-earth elements Yb, Ce and Tb analyzed for our samples and compared to metamorphic zircons from eclogitic metasediment (Eclogitic micaschist), ultrahigh-pressure eclogites and metasediments (UHP eclogite), garnet(grt)-bearing granulites and garnet(grt)-free granulites32. The fields correspond to additional analyses of zircons from ultrahigh-pressure eclogites (UHP eclogite91), ultrahigh-pressure garnet-bearing felsic to intermediate granulites (UHP Grt-granulite92), ultrahigh-temperature garnet-bearing aluminous granulite (UHT Grt-granulite93), and garnet-bearing aluminous granulite and anorthosite94. The composition of zircons from our samples indicates affinity with partial melts from garnet-bearing high-temperature crustal sources. Data for the reproduction of literature fields are present in Supplementary Data 8. C KDEs of crystallization pressure estimates using the ¹⁷⁶Lu/¹⁷⁷Hf ratio of individual grains as a pressure proxy38. D Oxygen fugacity for individual zircon grains expressed as ΔQFM units along the quartz-fayalite-magnetite buffer calculated using the zircon-melt partitioning of cerium model40 (errors are in 1σ). The pink dashed lines depict the ages (2000 Ma and 1770 Ma) when the transition from more oxidizing to more reducing conditions took place during cycles 1 and 3. Trace-element, Ti-in-zircon, and oxygen fugacity results are present in the Supplementary Data 5.
