Westhessische Senke
The hill is composed of basalt that fills the neck of a now-extinct volcano. The volcanic activity was during the Miocene (Neogene), that is it started and ended . This volcano was one of many in the West Hesse Depression. The alkali basalt has a silica (SiO2) volume percentage of 45–55%. The main minerals in the rock are plagioclase, augite and olivine.