From single batholith to global detrital zircon archive: Earth dynamics as seen from zircon Eu anomalies

Due to the continuous reworking of the continental crust and the limited rock record associated with the early Earth, the long-term evolution of the Earth's continental crust is mostly studied using the physically- and chemically-resistant mineral zircon. In particular, the europium anomaly [Eu/Eu* = EuN/(SmN x GdN)0.5; where the subscript N denotes chondrite-normalized] of detrital zircon populations has been proposed as a robust proxy for tracing the evolution of crustal thickness. However, recent studies have made the use of the zircon Eu anomaly for geodynamic reconstructions controversial. To provide new insights into the petrological controls on zircon Eu/Eu*, we first review the zircon archive and the evolution of the Adamello batholith, the largest Tertiary intrusion in the Alps and one of the best-studied examples for elucidating the genesis and evolution of continental arc magmas. From the existing extensive zircon archive, the Eu/Eu* in the different intrusive super-units de...