Geochemistry of Early Devonian rocks of the Sakmara zone, South Urals

This paper reports first isotope–geochemical data on the Early Devonian magmatic rocks of the Chanchar potassic mafic volcanoplutonic complex of the Sakmara zone of the South Urals. The incompatible element distribution and ratios indicate that the rocks of the volcanic, subvolcanic, and intrusive facies are comagmatic and were derived from a common source. The low HFSE concentrations relative to MORB and relatively low 87Sr/86Sr and high 143Nd/144Nd ratios suggest that primary melts were generated from a moderately depleted mantle. The LILE enrichment of the rocks indicates a flux of mantle fluid in the primary magma during its evolution.