The graphic below shows how the movement of the Earth's tectonic plates causes volcanoes to be formed, and what triggers a volcanic eruption.

All of those active volcanoes form over or in a subduction zone environment. The same types of processes that result in volcanic eruptions are processes that form gold deposits," explains Adam ...

Shield volcanoes do not have such violent eruptions ... and magma here can gradually rise and form new crust, usually without any violent eruptions. Destructive plate boundaries are where tectonic ...