The entire volcanic Kaiserstuhl consists of rock types that contain feldspathoid minerals and olivine and are undersaturated with SiO2. Most igneous rocks at the surface are leucite-tephrites, with subordinate phonolites, limburgites, and olivine-nephelinites (at the Limberg Mountain near Sasbach), the last of which is rich in xenoliths from the Earth's mantle. Carbonatite ignimbrite and lapilli are local peculiarities; they can be found in places in the western part of the Kaiserstuhl (Henkenberg near Burkheim, Kirchberg near Oberrotweil).