Figure 15. SiO2 vs. MgO, TiO2 vs. MgO, Al2O3 vs. MgO, and CaO vs. MgO variation diagrams for Belomorian basites (drusites) with ages of 2.50-2.41 Ga. 1 - drusites of the magnesian suite; 2 - drusites of the high-Fe suite.