Read this excerpt from "Mars: Landscape of the Red Planet." Mars's complexity goes well beyond its surface. Much of the red planet was formed from volcanic material. The southern part of Mars appears to have formed from volcanic activity. This part of Mars has an ancient crust that is mainly mafic in composition and contains high levels of iron and magnesium. The lowlands in the northern parts of Mars are younger and consist mostly of felsic rock, which is high in potassium, silicon, and aluminum. What is the best description of the geology of Mars? It is diverse, and different parts formed at different times. It is like Earth, with volcanoes, ocean valleys, and thick crust. It is simple, containing the same type of material and appearance everywhere. It is like the moon, because it is made of rock inside and on the surface.