The volcano complex lies in the
East Eifel between the villages of
Ettringen and
Kottenheim and the town of
Mayen on the edge of a
fault zone of the
Middle Rhine Basin. Violent movements caused disturbances in the
bedrock, so that, along this fault,
magma rose from a chamber at a depth of 10–20 km. Volcanic activity began approximately 200,000 years ago in the eastern part of the Bellerberg Volcano. Gaseous, 1,100 °C hot magma reached the Earth's surface at several eruption centres and formed smaller
cinder cones. Huge quantities of lava fragments, which were thrown mainly in an easterly direction, formed the cinder ridge of the
Kottenheimer Büden. Gradually, a crescent-shaped
crater wall formed, which probably grew to more than 20 m high within a few days. In addition, longer fissures appeared, which produced large quantities of lava and thus gave rise to the
Ettringer Bellerberg. At a later date, gas pressure from the magma chamber decreased and the explosive fountains dried up. Instead, three lava streams flowed out of the Bellerberg Volcano which, thousands of years later were to become the basis of the economy in the surrounding villages in the form of
basalt lava deposits: the Ettringer lava stream, the Mayen lava stream and the Winfeld lava stream. The Ettringen lava stream was the shortest, but most powerful of the three, and later formed the quarry area of the
Ettringer Lay. The longest was the Mayen lava stream. Lava flowed more than 3 kilometres south into the valley of the
Nette and was the basis for the quarries of the
Mayener Grubenfeld. The northern stream, the Winfeld lava stream, became the quarry area of
Kottenheimer Winfeld. • Angelika Hunold:
Das Erbe des Vulkans. Eine Reise in die Erd- und Technikgeschichte zwischen Eifel und Rhein. Schnell + Steiner und Verlag des
Römisch-Germanischen Zentralmuseums, Regensburg/Mainz 2011, == References ==