<Li> Columbia Gorge (Washington / Oregon, USA) </Li> <P> Basalt is a common rock on all terrestrial planets (Mercury, Venus, Mars) and the Moon . Many meteorites have the same chemical composition as basalt . </P> <P> The dark areas visible on Earth's moon, the lunar maria, are plains of flood basaltic lava flows . These rocks were sampled by the manned American Apollo program, the robotic Russian Luna program, and are represented among the lunar meteorites . </P> <P> Lunar basalts differ from their Earth counterparts principally in their high iron contents, which typically range from about 17 to 22 wt% FeO . They also possess a wide range of titanium concentrations (present in the mineral ilmenite), ranging from less than 1 wt% TiO, to about 13 wt.% . Traditionally, lunar basalts have been classified according to their titanium content, with classes being named high - Ti, low - Ti, and very - low - Ti . Nevertheless, global geochemical maps of titanium obtained from the Clementine mission demonstrate that the lunar maria possess a continuum of titanium concentrations, and that the highest concentrations are the least abundant . </P>

Magma that is rich in magnesium and iron is called