Just to add a bit. The German deep drilling project was in Germany to test drilling methods and to see conditions at great depth.
The Hellvelyn Caldera in the Lake District is bigger than you might think... when you think of the sq.miles of the volcanic lithologies present there (basically most of the Lake District). One might also include the Sill 'intrusions' underneath Durham and parts of Yorks., let alone the other granite/basalt areas of GB. GB was not without it's turmoil once upon a time! The Weardale lead/flourspar mines came across the Whin Sill at varying depths, but usually on avarage at 200 metres, however, in Teesdale, 'The Whin' outcrops, and was quarried for many years. All was uplifted one way and another during various geologic times, but in Durham/Yorks, the Limestone etc. gives a good indicative date line. Flourspar, being Calcium Flouride, is indicative of volcanic activity, and some of the 'vents' in Iceland have a nasty habit of ejecting nasty amounts flourine gas - which is highly toxic. In Weardale, granite os apx. 1 kilometer down (viz. the Rookhope Excpl. Borehole), mid-Wales, it is estimated to be apx. the same, but funding to prove this has not been authorised thus far. Ireland, well the lithologies are well known, as also Scotland. What goes on between Anglesea and Ireland is another matter, but the Isle of Man is indicitive... though a bit northerly and nearer to the Leadhills of Scotland.
Redgards, Bernard