Summary: The potash feldspar in the charnockites is orthoclase and they are inferred to have been formed around 700 °C. A twin-law study of the plagioclase indicates an igneous origin of the charnockites and pyroxene granulites. The K_D values of the coexisting pyroxenes in the granulites are appropriate to equilibrium at 670 °C. A substantial substitution of A1 for Si in the values of the coexisting pyroxenes in the granulites are appropriate to equilibrium at 670 °C. A substantial substitution of A1 for Si in the _Z group in all mafic minerals studied also indicates relatively high temperatures of formation. Almandine is pyroperich, a result of high pressure. The charnockites and pyroxene granulites are inferred to be formed under conditions of high pressure and temperature.