The "Swabian Volcano"
“Scharnhausen Volcanoe” – this term sounds much more spectacular than it is in reality. No lava, no rising ash clouds but only a poorly exposed tuff diatreme at the slope of a creek valley.
This diatreme is the northern most one of the “Swabian Volcano”, which had perforated the Swabian Alb in more than 350 places approximately 14 million years ago, in the Miocene. The special importance of the “Scharnhausen Volcano”: since 125 years it is proved that the Swabian Alb extended to the area of Stuttgart in the active time of volcanism, over 20 kilometres more distant than today, because of Upper Jurassic limestone xenoliths found in the filling of the diatreme.
My personal interest in the “Swabian Volcano” arouse at the beginning of my geological studies at Stuttgart University (1983-90). I had to give a seminary talk – my first one in life. The topic of this talk specified by the lecturer was the Tertiary volcanism in southwestern Germany. Since that time this subject did not get out of my focus.