Features of counter chemical diffusion of petrogenic components (SiO₂, Al₂O₃, Na₂O, CaO, MgO, FeO) and CO₃²⁻ Anion in the Interaction of Basalt and Kimberlite Melts At P–Т Parameters of the Upper Mantle (Experimental Study)

New results have been obtained from experimental studies of the characteristics of counter chemical diffusion of the main petrogenic components (SiO2, Al2O3, Na2O, CaO, MgO, FeO) and the CO₃²⁻ anion during the interaction of basalt and kimberlite melts at mantle pressures. The studies were carried out by the diffusion pair method using an original high-pressure installation of the “BARS” type at a pressure of 5.5 GPa and a temperature 1850°C. It has been shown that the rate of counter chemical diffusion of all the main components of melts (SiO2, Al2O3, Na2O, CaO, MgO, FeO) and the CO₃²⁻ anion is almost identical in the interaction of model basalt and kimberlite carbonate-containing melts, and is approximately 1 order of magnitude greater than the diffusion rate these components during the interaction of such melts at moderate pressures (100 MPa). The equal rates of diffusion of CaO and the CO₃²⁻ anion indicate that the diffusion of carbonate CaCO3 from the kimberlite into the basaltic (model and natural) melt remains of the minal nature even at such a high pressure. The diffusion pattern changes significantly during the interaction of a melt of natural magnesian basalt and model kimberlite, as was the case during the interaction of such melts at moderate pressures. In this case, along with the minal diffusion of calcite into magnesian basalt, the diffusion rates of the remaining components of the melts become significantly higher. A weak exponential concentration dependence of all diffusing components has been established, which is close to Di = const, and which occurred during the interaction of such melts at moderate pressures.