Editing Charles Lyell (section)

===Volcanoes and geological dynamics===
[[File:Vesuvius from plane.jpg|thumb|Lyell argued that volcanoes like [[Vesuvius]] had built up gradually.]]
Before Lyell's work, phenomena's such as earthquakes were understood by the destruction that they brought. One of the contributions that Lyell made in ''Principles'' was to explain the cause of earthquakes.{{sfnp|Adams|1938|p=}} Lyell, in contrast, focused on more recent earthquakes (150 yrs), evidenced by surface irregularities such as faults, fissures, stratigraphic displacements and depressions.{{sfnp|Adams|1938|p=}}

Lyell's work on volcanoes focused largely on [[Vesuvius]] and [[Mount Etna|Etna]], both of which he had earlier studied. His conclusions supported gradual building of volcanoes, so-called "backed up-building",{{sfnp|Bailey|1962}} as opposed to the upheaval argument supported by other geologists.