JA Volcano is an

inactive volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are ...

located near

Albuquerque, New Mexico Albuquerque ( ; ), ; kee, Arawageeki; tow, Vakêêke; zun, Alo:ke:k'ya; apj, Gołgéeki'yé. abbreviated ABQ, is the most populous city in the U.S. state of New Mexico. Its nicknames, The Duke City and Burque, both reference its founding in ...

. JA Volcano is the southernmost of 5 volcanoes in a 5-mile chain within the western boundary of

Petroglyph National Monument Petroglyph National Monument stretches along Albuquerque, New Mexico's West Mesa, a volcanic basalt escarpment that dominates the city's western horizon. Authorized June 27, 1990, the 7,236 acre (29.28 km2) monument is cooperatively mana ...

. The volcano has been the site of repeated pranks:

"Volcano “Erupts” But Fools No One—a 1950 newspaper headline declared. Nobody was fooled, apparently, because the same prank—piling tires on the side of a volcano and setting them on fire to simulate an eruption—had been tried in 1947 with much greater success (even causing a panic in the city). For years students from nearby St Joseph would paint a "J" on Vulcan Volcano, when the light is right it can still be seen." St. Joseph College was later named the University of Albuquerque. In 1950 the College of St. Joseph began its move into a newly built campus on the palisades along the Rio Grande below the volcano. The name was changed to the College of St. Joseph on the Rio Grande. In 1966, the institution changed its name again to the
University of Albuquerque The University of Albuquerque was a Catholic liberal arts university in Albuquerque, New Mexico, which opened in 1920 and closed in 1986. Its former campus on Albuquerque's West Side now houses St. Pius X High School. History The institution was ...
. Twenty years later, it closed its doors and became the campus of Pius X high school.

The volcano is composed of a type of volcanic rock called

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 ...

tholeiitic The tholeiitic magma series is one of two main magma series in subalkaline igneous rocks, the other being the calc-alkaline series. A magma series is a chemically distinct range of magma compositions that describes the evolution of a mafic magma i ...

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

Radiometric dating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares t ...

indicates an age for this rock of about 156,000 years. The volcano consists of two flows with a spatter cone at the center. Late in the eruption, subterranean pressure bulged the surface beneath the cone, causing radial cracking that resulted in emplacement of

dikes Dyke (UK) or dike (US) may refer to: General uses * Dyke (slang), a slang word meaning "lesbian" * Dike (geology), a subvertical sheet-like intrusion of magma or sediment * Dike (mythology), ''Dikē'', the Greek goddess of moral justice * Dikes, ...

around the cone. A final explosion blew out the eastern rim of the cone.

References

Volcanoes of New Mexico Inactive volcanoes Pleistocene volcanoes Landforms of Bernalillo County, New Mexico Stratovolcanoes of the United States {{NewMexico-geo-stub