EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Statistical analysis of Europium anomalies in detrital zircons record major transitions in Earth geodynamics at 2.5 Ga and 0.9 Ga

Antoine Triantafyllou1, Mihai Ducea2,3, Gilby Jepson4, Alex Bisch1, and Jerome Ganne5
Antoine Triantafyllou et al.
  • 1Lyon Geology Laboratory–Earth, Planets and Environment, Université Lyon 1, École Normale Supérieure de Lyon, CNRS UMR 5276, 69622 Villeurbanne, France
  • 2Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA
  • 3Faculty of Geology and Geophysics, University of Bucharest, Bucharest 010040, Romania
  • 4School of Geosciences, University of Oklahoma, Norman, OK 73019, USA
  • 5Geosciences Environnement Toulouse, Observatoire Midi Pyrénées, Institut de Recherche pour le Développement (IRD), 31400 Toulouse, France

Trace elements in zircon are a promising proxy to quantitatively study long-term Earth’s lithospheric processes and its geodynamic regimes. The zircon Eu anomaly reflects the crystallization environment of its felsic or intermediate parental magma. It specifically provides insight into the water content, magmatic redox conditions, and the extent of pla­gioclase fractionation in the source rock or its occurrence as a cogenetic crystallizing phase from the magma. We performed a statistical analysis of Eu anomaly from a global compilation of detrital zircons and display it as a timeseries and found a major decrease in Eu anomaly ca. 2.5 Ga and an important increase ca. 0.9 Ga. Combining these trends with thermodynamic modelling, we suggest that these variations could be due to long-term change in the chemical system of the mafic source from which the intermediate to felsic melt and derived zircons are produced. The 2.5 Ga drop was likely associated with an enrichment in incompatible elements in the mafic source, which extended the pressure-temperature field of plagioclase stability as a cogenetic melt phase. We interpret the 0.9 Ga rise to record increasing hydration of magmagenetic sites due to the general development of cold subduction systems, which would delay and/or suppress the saturation of plagioclase in hydrous magmagenetic sites.

How to cite: Triantafyllou, A., Ducea, M., Jepson, G., Bisch, A., and Ganne, J.: Statistical analysis of Europium anomalies in detrital zircons record major transitions in Earth geodynamics at 2.5 Ga and 0.9 Ga, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-1954,, 2023.