The explosive volcanic events that produced these tuffs were unbelievably large and violent many times greater than the 1981 eruption of Mount St. Helens.
(The explosive volcanic events; produced; these tuffs) (The explosive volcanic events that produced these tuffs; were greater; unbelievably large and violent)
The explosive volcanic events The explosive volcanic events that produced these tuffs
produced were greater
these tuffs
unbelievably large and violent