The 825 Ma Yiyang high–MgO basalts of central South China: Insights from Os–Hf–Nd data

High–MgO basaltic lavas, including komatiites and picrites, have long been used as probes of both the chemical and thermal evolution of the mantle through time. The ca. 825 Ma Yiyang high–MgO basalts in the central South China Block (SCB) were considered to be the first evidence for >1500 °C mantle melts by a Rodinian mantle plume. However, later studies proposed that they may have been generated within an arc setting and can be classified as...