Explore Geology
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Capulin Volcano

National Monument

New Mexico

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Photo of visitors standing on overlook at Capulin Volcano
Capulin Volcano National Monument, New Mexico

The Mountain Tells Its Story
Just yesterday, on the clock of geological time, the scene near Capulin would have been one of fire, ash, glowing lava, and ear-shattering explosions, for Capulin Mountain is the cone of a volcano that was active only about 62,000 years ago. This cinder cone represents the last stage of a great period of volcanism that had begun about eight million years earlier. Evidence of this activity can be seen in the scores of nearby volcanic hills and peaks. The largest of these is the Sierra Grande, an extinct volcano rising some 2,200 feet above the surrounding plain, about 10 miles to the southeast. To the northwest of Capulin are a number of mesas that are capped with lava, the three largest of which are Barella, Raton, and Johnson mesas.

In the great volcanic area, called the Raton-Clayton volcanic field, volcanism occurred in three main episodes, separated by long periods of inactivity. Capulin Volcano formed during the last period of activity. Its conical form rises more than 1,300 feet above the plains to 8,182 feet above sea level. The mountain consists chiefly of loose cinders, ash, and other rock debris. These materials were spewed out by successive eruptions and fell back upon the vent, piling up to form the conical mound.

The symmetry of Capulin Mountain was preserved because lava did not flow from the main crater but from secondary vents located at the western base of the cone. After the eruptions ceased, vegetation gained a foothold on the steep, unstable slopes, and in time, the mountain became stabilized as the dense root growth and the forces of nature changed the volcanic matter into soil.

Capulin Volcano has been inactive for a long enough period that it is unlikely it will erupt again. Basalt volcanic fields typically form a new cinder cone with each eruption. Thus, although Capulin itself may never erupt again, the formation of a new cinder cone in the Raton-Clayton volcanic field is probable sometime in the distant future. An eruption near Capulin in our lifetimes is very unlikely, but not impossible.

A Walk into a Volcano
Have you ever wanted to walk into a volcano? Well, Capulin Volcano is one of the few places in the world where you can do that. A 3-kilometer (2-mile) road spirals to the summit, ending at a parking area, where two self-guiding trails begin. One trail, 0.3 kilometers (0.2 miles) long, goes down to the bottom of the crater to the vent and gives you an unusual opportunity to see the inside of a volcanic mountain. The second is the Crater Rim Trail, 1.6 kilometers (1 mile) long, a self-guiding path that follows the rim all the way around. The trail begins with a moderate climb, but once on the rim you will find the going fairly easy until you begin the descent to the parking lot. From the trail, you can also look out over the land through which the "Cimarron Cut-Off" of the Santa Fe Trail passed. During the late-19th century, wagon trains bound for Fort Union traveled this route. The view westward is particularly magnificent. The majestic, snowcapped peaks of the Sangre de Cristo Mountains form a mighty backdrop to the wide expanse of rangeland, broken by volcanic hills and mesas. Be sure to hike both trails. It's not often that you can walk so brazenly in a volcano.

Near Capulin volcano is the famous Folsom archaeological site, located on private land and closed to the public. This is where artifacts of prehistoric humans were first found in association with the fossilized bones of extinct animals. The site was excavated in 1928 and 1929 by the Denver Museum of Natural History.

Four Lava Flows
Capulin Volcano eruptions produced two types of volcanic products:

  • cinders (frothy volcanic rock chunks), and
  • lava flows

Map of ash flows
The eruption began with a northwest-oriented fissure vent that soon came together to form a single central vent. This vent sent cinders high into the air; they piled up around the vent to produce the Capulin cinder cone. During this cinder eruption, the first lava flow oozed through the cinders to flow eastward. After the gas in the magma was depleted, lava flows then oozed out of the mouth on the west side of the cinder cone. These flows flowed at least partly in lava tubes, from the Boca first to the south (second lava flow), then southwest (third lava flow), and finally to the northeast and north (fourth lava flow), covering more than 25 square miles. Ripple marks on the surface of the lava are perpendicular to flow direction, and formed as the crust cooled but lava continued to flow underneath. Lava mounds called tumuli (squeeze-ups) formed where the lava crust broke and lava spewed out under pressure.

park maps subheading

The General park map handed out at the visitor center is available on the park's map webpage.

View the park's map to create your own personal maps and images right here.

For information about topographic maps, geologic maps, and geologic data sets, please see the geologic maps page.

photo album subheading

A geology photo album for this park can be found here.

For information on other photo collections featuring National Park geology, please see the Image Sources page.

books, videos, cds subheading

Currently, we do not have a listing for a park-specific geoscience book. The park's geology may be described in regional or state geology texts.

Please visit the Geology Books and Media webpage for additional sources such as text books, theme books, CD ROMs, and technical reports.

Parks and Plates: The Geology of Our National Parks, Monuments & Seashores.
Lillie, Robert J., 2005.
W.W. Norton and Company.
ISBN 0-393-92407-6
9" x 10.75", paperback, 550 pages, full color throughout

The spectacular geology in our national parks provides the answers to many questions about the Earth. The answers can be appreciated through plate tectonics, an exciting way to understand the ongoing natural processes that sculpt our landscape. Parks and Plates is a visual and scientific voyage of discovery!

Ordering from your National Park Cooperative Associations' bookstores helps to support programs in the parks. Please visit the bookstore locator for park books and much more.

geologic research subheading


For information about permits that are required for conducting geologic research activities in National Parks, see the Permits Information page.

The NPS maintains a searchable data base of research needs that have been identified by parks.

A bibliography of geologic references is being prepared for each park through the Geologic Resources Evaluation Program (GRE). Please see the GRE website for more information and contacts.

selected links subheading

NPS Geology and Soils Partners

NRCS logoAssociation of American State Geologists
NRCS logoGeological Society of America
NRCS logoNatural Resource Conservation Service - Soils
USGS logo U.S. Geological Survey

teacher feature subheading

General information about the park's education and intrepretive programs is available on the park's education webpage.

For resources and information on teaching geology using National Park examples, see the Students & Teachers pages.
updated on 01/04/2005  I   http://www.nature.nps.gov/geology/parks/cavo/index.cfm   I  Email: Webmaster
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