Geology

Map of Valles Caldera with color codes indicating age of volcanic domes, from 1.2 to 1.6 million years old
Valles caldera map modified from "The Geology of Northern New Mexico’s Parks, Monuments, and Public Lands", page 137.

Image courtesy of New Mexico Bureau of Geology and Mineral Resources

Valles Caldera National Preserve is located in the Jemez volcanic field at the intersection of two major fault systems, the Rio Grande Rift and the Jemez Lineament. The rift, a stretching and thinning area of the earth’s crust, extends from central Colorado to the state of Chihuahua, Mexico, and the lineament, a chain of volcanic fields, spans from east-central Arizona to the Raton-Clayton volcanic field in northeastern New Mexico.

The Jemez volcanic field started forming more than 14 million years ago with a series of eruptions, including at least two especially explosive events. The most recent event (about 1.25 million years ago) formed Valles Caldera. Following the eruption, the surrounding earth collapsed into the volcano's drained magma chamber, forming the broad, 12- to 15-mile-wide circular caldera you can visit today.

Since that time, an additional 15 eruptions have created numerous volcanic domes within the caldera, including the major central resurgent dome, Redondo Peak, which serves as the type locality (or model) for understanding caldera resurgence worldwide.

The caldera is dormant, but not extinct, and still displays signs of volcanic life with hot springs and boiling sulphuric acid fumaroles. The unusual geologic and landscape characteristics of Valles Caldera led to its designation as a Natural National Landmark in 1975.

 
 

Explore the Volcanic Landscape

  • A bubbling volcanic mudpot

    Sulphur Springs

    The premier location to witness volcanic activity at Valles Caldera.

  • A small, forested dome amid an expansive, foggy valley.

    Cerro La Jara

    Cerro La Jara is the youngest volcanic dome in the park.

  • A smooth piece of black, transparent rock in the snow.

    Obsidian Valley

    A significant source of volcanic glass for toolmaking and trade for 12,000 years.

 

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    Last updated: December 5, 2022

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    Mailing Address:

    PO Box 359
    Jemez Springs, NM 87025

    Phone:

    505-670-1612
    Ranger Station (for general park information)

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