Jemez Mountains
The Jemez mountains are a volcanic field in north central New Mexico that
overlies the west edge of the Rio Grande rift. Volcanism began 13 million
years ago, tho the most recent activity was 130,000 years ago.
The volcanic field is known for the Valles caldera which formed
1.12 million years ago producing the Bandelier Tuff.
The Valles caldera is the most studied caldera in the United States.
The geothermal and hot springs systems are caused by flow of groundwater
through the caldera. The water flows near the top of a subsurface body of
igneous rock that still may be partially molten (it is certainly still hot).
Some of the water rises to the surface to supply fumaroles and hot springs.
Based on the history of the Jemez volcanic field and past cycles in
activity it should be considered a dormant volcano that will erupt again.