What is a volcanic field?

Bonito lava flow at Sunset Crater
Basalt flow, San Francisco Volcanic Field, northern Arizona. Details

Volcanic activity is not evenly distributed in time or space across the surface of the Earth, but instead is concentrated in different areas on the Earth's surface. A volcanic field is an area on the Earth's crust that is prone to localized volcanic activity and is usually covered with volcanic materials produced during past eruptions. A volcanic field may have been active during a single eruptive event, during a protracted period of related volcanic activity, or during unrelated periods of activity widely separated in geologic time.

Volcanic fields are of particular interest to geologists for several reasons. Concentrations of related volcanic materials which span a range in geochemical composition are natural laboratories where petrologists can learn about processes which lead to the production of different kinds of magma. The diversity of landforms in volcanic fields has also expanded our knowledge of volcanic processes and their effects on the land and environment. The regional distribution of volcanic fields and their differences in age and geochemistry highlight the important role of plate tectonics in shaping our planet. Finally, the more recently-active fields mark locations of heightened geologic activity and elevated risk from volcanic hazards.