The Ofenkaulen
The mountain Ofenkaulberg in North Rhine-Westphalia is made up of trachyte tuff. The rock formed as a result of volcanic eruptions that took place approximately 25 million years ago. These eruptions were the beginning of long lasting volcanic activities in the Siebengebirge. Tectonic activity in the Lower Rhine embayment is associated with the volcanic activity. … Continue readingThe Ofenkaulen