Petrology, geochemistry and zirconology of impure calcite marbles from the Precambrian metamorphic basement at the southeastern margin of the North China Craton

Positive Eu anomalies and high Sr and Ba contents in type 2 marbles are ascribed to syn-depositional felsic hydrothermal activity which occurred at 2.53 − 2.48 Ga. Our results, together with other published data and the inferred tectonic setting, suggest that the marbles' protolith is an impure limestone, rich in detrital silicates of igneous origin, deposited in a back-arc basin within an active continental margin during the late Archean and affected by synchronous high-T hydrothermalism at the southeastern margin of the North China Craton.