Composition and Parameters of Generation of Primary Magma of Ultramafic Massif Uitkomst: Thermobarogeochemical Study of Microinclusions

Primary melt inclusions in olivine from ultramafic rocks of the Uitkomst Massif, South Africa were studied. It was found that the parent magma has high levels of MgO (up to 22.5 wt%), FeO, SiO2 and LREE, the content of CaO, alkalis, volatiles and fluid-mobile components. Melting of magma took place at a temperature of 1590 °C and a pressure of 2.5 GPa. The main process of magma evolution in the early stages was crystallization differentiation, which was complicated by contamination by crustal matter as the magma moved to the Earth’s surface.