Figure 6. Classification, according to standard schemes, of the oxide abundances and calculated mineralogies for the four geochemical terranes identified by McCoy et al. (2018), as well as for a southern hemisphere (average Mercury) composition. A: Total alkalis versus silicate diagram. The field for high-Mg rocks (Le Bas, 2000) is shown in green, indicating that all of the Mercury compositions can also be classified as boninites. The terrane mineralogies are also shown on International Union of Geological Sciences diagrams for plutonic rocks, in terms of (B) plagioclase–orthopyroxene–clinopyroxene and (C) plagioclase–pyroxene–olivine.