Volcanic activity or phenomena.
- ‘This appears to contradict evidence from other areas, particularly Wales where subduction-related volcanism occurs in the late Tremadoc.’
- ‘The scattered nature of the outcrop and the possibility of diachronous volcanism mean that all rocks grouped as Dokhan Volcanic Series may not be coeval.’
- ‘The onset of volcanism in the region occurred in late Ordovician times, with the earliest eruptions associated with the Eycott and Borrowdale volcanic groups.’
- ‘Carboniferous volcanism, occurring at converging plates margins, both at the Appalachian and at the Ouachita margins, was decidedly not tholeiitic.’
- ‘The radiometric age data combined with the petrography of the volcanics thus indicate two separate events of volcanism in the Danish North Sea.’