Capulin Volcano

Location: 36 degrees 47 minutes N latitude, 103 degrees 59 minutes W longitude Type: Basaltic scoria cone Age: 56,000 to 62,000 years Significance: Large and symmetric example of a basaltic scoria cone; first National Monument; and paved road to summit crater.

Capulin Volcano is one of the youngest volcanoes in the Raton-Clayton volcanic field and a classic and symmetrical, example of what volcanologists refer to as a "cinder cone," or "scoria cone." It is unusual for several reasons. It is big. It is nearly a mile across at its base, has a relief of nearly 1,000 feet, and a summit crater more than 300 feet deep, making it one of the larger examples of this type of volcano. Parícutin volcano in Mexico (the one that erupted in 1943 in a Mexican farmer's corn field) and Sunset Crater in Arizona (near Flagstaff) are two other young cinder cones of similar size. Capulin Volcano is one of the few volcanoes whose summit can be reached on a paved road in a private vehicle. It is the only volcano on the continent with a parking lot on the crater rim, so anyone may visit the crater.

Recent work by geologists from College of Santa Fe, Northern Arizona University, and NM Tech in conjunction with the Park Service (Sayre et al, 1995; Stroud, 1996), has resulted in new geologic mapping and age dates. This new work indicates that Capulin Mountain erupted approximately 56,000 to 62,000 years ago, a somewhat older age than the reported age based on correlation with the famed Folsom paleosite (~11,000 years ago). Capulin Mountain is a classic cinder cone with associated small volumes of lava flows and is similar in size, morphology, and probably eruptive characteristics to Parícutin volcano, Mexico.

A complicated series of lava flows and cinder/spatter eruptions occurred, during or after eruption of the cinder cone, in order to build Capulin Volcano. Three major series of lava flow units occurred, the earliest flowed to the east-southeast of the cone, the second to the west and south, and the third to the west and north. The second and third series of flows were erupted from an area at the base of the cone called the boca (mouth) and during these eruptions several intermittent lava lakes formed at the lower flanks of the volcano and portions of the cone were "rafted" away on the surface of the flows.

In map plan view, the base of the cone is somewhat elongated. Morphometric analysis of the cone, its summit crater shape, and the distribution of late ash on the cone flanks suggests that the vent moved laterally to the west late in the construction, possibly as a result of slumping on that side during emplacement of the late lava flow unit (see model section below).