New Mexico Museum of Natural History and Science

Verical erosion through a classic volcanic field; near surface structure of scoria cones and maars

Alkali basalt

There is no other place on Earth where the interiors of young volcanoes are so well exposed as in the Rio Puerco. Cabezon is one of many massive dark peaks known as volcanic necks that are scattered throughout the Rio Puerco valley between Mesa Chivato and Mesa Prieta on the west and east, and San Luis and I-40 on the north and south. Together with Mesas Chivato and Prieta they are part of the Mount Taylor volcanic field, a cluster of several hundred small volcanoes. A few volcanic necks, including Cerro Alesna, occur on the west side of Mesa Chivato. Other examples around the south margin of the Mount Taylor field include half-sectioned volcanoes (east Grants Ridge) and deeply dissected volcanoes (Cubero volcano).

They are all the near-surface interiors of small volcanoes that are geologically young, yet were deeply dissected when the Rio Puerco cut a valley through the Mount Taylor volcanic field. Backwasting of the lava flows and erosion of the volcanoes themselves has exposed the complex interiors of many of the small volcanoes.One may see violent events recorded in their complex structure. The eruptions were similar to those that form small scoria cones, such as Capulin or Bandera volcanoes, and in some cases, similar to that which formed Zuni Salt lake or Kilbourne Hole.

Cabezon

Cabezon

Cerro Alesna

East Grants Ridge (Half section scoria cone)

Rio Puerco dike

New Mexico Centennial Stamp (Santa Clara and Cerro Guadalupe)

Sun behind Cerro Guadalupe

Annular Eclipse, May 20, 2012, through Cerro Guadalupe

Santa Clara

Santa Clara Aerial

View Mt. Taylor Volcanic Necks in a larger map

Explore New Mexico's Volcanoes

New Mexico Volcano Directory
A map of volcanoes and volcanic features around the state, with detailed discussion of each site.

Volcanoes of New Mexico
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