Why are there no volcanoes in Belgium?

Answer

The volcanoes in the German Eifel are ‘dormant’ volcanoes. We indeed consider these as ‘active’. So they can still erupt … and probably ever will. The last eruption happened about 10,000 years ago.
The ‘volcano’ of Vlieland is deeply buried. This volcanic complex that was drilled there is about 152 million years old. This is a remnant of an old volcano.
The Queanst porphyry quarry is almost circular. This actually forms the underground supply pipe of an ancient volcanic complex. But this volcano was active about 450 million years ago. In Bierghes and Lessines we find underground intrusions that are part of this volcanic complex.
A volcano is indeed an active system. So in this list we only find volcanoes in the Eifel.
And why are there no volcanoes in Belgium? Because we are just not in a tectonic active area (= the edges of the tectonic plates), such as in Iceland for example. And we are not above a glow point (or ‘hot spot’), as is the case in the Eifel.
But on the basis of Quenast’s porphyry, we know that about 450 million years ago we were on a plate boundary, somewhat comparable to present-day Indonesia.