volcanic field
A volcanic field is an area of Earth's crust that is prone to localized volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. Volcanic fields usually consist of clusters of up to 100 volcanoes ...
located in
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ker ...
The field consists of the Cat Hills cones and flows, Wind Mesa, and Isleta volcano and Los Lunas volcano. These are located in close proximity to each other, but show a diversity of compositions and ages.
The oldest volcano of the field is Isleta volcano, which is located about west of
Isleta Pueblo
Pueblo of Isleta ( tix, Shiewhibak , kjq, Dîiw'a'ane ; nv, Naatoohó ) is an unincorporated community and Tanoan pueblo in Bernalillo County, New Mexico, United States, originally established in the . The Southern Tiwa name of the pueblo ...
.
I-25
Interstate 25 (I-25) is a major Interstate Highway in the western United States. It is primarily a north–south highway, serving as the main route through New Mexico, Colorado, and Wyoming. I-25 stretches from I-10 at Las Cruces, New Mexic ...
crosses its eastern flank. The volcano has a K-Ar age of 2.78 Ma. Isleta volcano is a cone built over a
maar
A maar is a broad, low-relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma). A maar characteristically fills with water to form a relatively shallow ...
, and consists of
alkali olivine basalt
Alkali basalt or alkali olivine basalt is a dark-colored, porphyritic volcanic rock usually found in oceanic and continental areas associated with volcanic activity, such as oceanic islands, continental rifts and volcanic fields. Alkali basalt ...
.
Los Lunas volcano is located on the eastern escarpment of Ceja Mesa, about west of
Los Lunas
Los Lunas is a village in Valencia County, New Mexico, United States. As of the 2010 census, the village population is 14,835 inside the village limits due to the new housing developments at El Cerro de Los Lunas (Huning Ranch). It is the county ...
. It shows evidence that flows cascaded from the vent down the escarpment, showing that the volcano is younger than the escarpment. The lavas have been dated at 1.1 to 1.3 Ma based on K-Ar dating, which constrains the age of the Ceja surface and the Ceja Formation. The position on the escarpment means that the peak is imposing viewed from the east (with an apparent
topographic prominence
In topography, prominence (also referred to as autonomous height, relative height, and shoulder drop in US English, and drop or relative height in British English) measures the height of a mountain or hill's summit relative to the lowest contou ...
of ) but much less so viewed from the west, where the apparent topographic prominence is just . The volcano is composed of
andesite
Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomi ...
erupted from two closely spaced vents.
The youngest volcanoes of the field are the Cat Hills themselves, which form a chain of 23
cinder cone
A cinder cone (or scoria cone) is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around a volcanic vent. The pyroclastic fragments are formed by explosive eruptions o ...
s following a hidden fissure that strikes just east of north. The fissure also erupted extensive flows, covering an area of about . The cinder cones range in size from in diameter and tall to in diameter and tall. All show summit craters and are obviously young. They have been mined extensively for
cinder
Cinder is an alternate term for scoria.
Cinder or Cinders may also refer to:
In computing
*Cinder (programming library), a C++ programming library for visualization
*Cinder, OpenStack's block storage component
* Cyber Insider Threat, CINDER, a ...
, with one cone quarried completely away by 1978. K-Ar dating gives an age of 0.14 Ma. All are composed of alkali olivine basalt similar to that of Isleta volcano.
Wind Mesa is undated but seems to lie just east of the same fissure zone as the Cat Hills and about west of Isleta volcano. The mesa is truncated by faults on both the west and east sides, and is composed of an
olivine
The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickl ...
-bearing
basaltic andesite
Basaltic andesite is a volcanic rock that is intermediate in composition between basalt and andesite. It is composed predominantly of augite and plagioclase. Basaltic andesite can be found in volcanoes around the world, including in Central Ameri ...