| Not all the striking effects of vulcanism belong to the remote geologic past. |
| In fact, the cataclysm may have been a combination of vulcanism and bolide impact. |
| As a marine geologist, his research focuses on the deep-sea vulcanism of the Juan de Fuca Ridge in the northeast Pacific Ocean. |
| Thus as we travel up the rich valleys leading from the Columbia to either peak, we meet everywhere the phenomena of vulcanism. |
| Valleys formed in grabens are commonly called rift valleys and may exhibit features of vulcanism often associated with graben formation. |
| From vulcanism to the extinction of species to global climate change and on to creation itself, she tackles complex topics with dexterity. |
