noun[mass noun] Geology
- Volcanic activity or phenomena: extensive volcanism occurred during the Ordovician in the Lake District and WalesMore example sentences
- Carboniferous volcanism, occurring at converging plates margins, both at the Appalachian and at the Ouachita margins, was decidedly not tholeiitic.
- 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.
More definitions of volcanismDefinition of volcanism in:
- The US English dictionary