Michoacán–Guanajuato volcanic field is located in the Michoacán and Guanajuato states of central Mexico. It is a

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 ...

that takes the form of a large cinder cone field, with numerous shield volcanoes and maars. Pico de Tancítaro (3860 m) is the highest peak. The volcanic field is best known for the 18th-century eruption of

Jorullo El Jorullo is a cinder cone volcano in Michoacán, central Mexico, on the southwest slope of the central plateau, 33 miles (53 kilometers) southeast of Uruapan in an area known as the Michoacán-Guanajuato volcanic field. It is about 6 mi ...

volcano, and 20th-century eruption of

Parícutin Parícutin (or Volcán de Parícutin, also accented Paricutín) is a cinder cone volcano located in the Mexican state of Michoacán, near the city of Uruapan and about west of Mexico City. The volcano surged suddenly from the cornfield of loca ...

volcano.

Morphology

The Michoacán–Guanajuato volcanic field covers an area of , in the states of Michoacán and Guanajuato. It contains 1400 vents, mostly cinder cones. The shield volcanoes are mostly

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

in age. The field includes

Siete Luminarias Siete Luminarias (The Seven Luminaries) is a group of seven extinct volcanoes in central Mexico, located in and around the town of Valle de Santiago in the state of Guanajuato. Geography The Siete Luminarias are low-rimmed volcanoes, or maars, w ...

, a group of seven maars in and around

Valle de Santiago Valle de Santiago is a ''municipio'' (municipality) in the Mexican state of Guanajuato, and also the name of its largest township and '' cabecera municipal'' (municipal seat). The municipality is located in the southern portion of the state in th ...

in Guanajuato. Other volcanoes in the field include Alberca de los Espinos in Michoacán and Cerro Culiacán in Guanajuato. The cinder cones are randomly arranged and occur at low altitudes, usually, on alluvial plains or on the flanks of eroded shield volcanoes. There are an average of 2.5 cinder cones every ².

Eruptions

El Jorullo — 1759−1774

El Jorullo El Jorullo is a cinder cone volcano in Michoacán, central Mexico, on the southwest slope of the central plateau, 33 miles (53 kilometers) southeast of Uruapan in an area known as the Michoacán-Guanajuato volcanic field. It is about 6 mi ...

volcano began on September 29, 1759.

Earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

s occurred prior to this first day of the eruption. Once the cinder cone started erupting, it continued for 15 years, eventually stopping in 1774. El Jorullo destroyed what had been a rich agricultural area. It grew approximately from the ground in the first six weeks. The eruptions from El Jorullo were primarily

phreatic ''Phreatic'' is a term used in hydrology to refer to aquifers, in speleology to refer to cave passages, and in volcanology to refer to a type of volcanic eruption. Hydrology The term phreatic (the word originates from the Greek , meaning "well" ...

and phreatomagmatic. They covered the area with sticky mudflows, water flows, and

ash falls Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non-gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash i ...

. All but the youngest lava flows were covered by this ashfall. Later eruptions from El Jorullo were magmatic with neither mud nor water flows. This 15-year eruption was the longest one El Jorullo has had and was the longest cinder cone eruption known. Lava flows can still be seen to the north and west of the cinder cone. The eruption had a VEI of 4. Its current elevation is , and its crater is about wide and deep. El Jorullo has four smaller cinder cones which have grown from its flanks. The vents of El Jorullo are aligned in a northeast to southwest direction. Lava from these vents cover nine km² around the volcano. Later eruptions produced lavas that had higher

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is ...

contents making them more viscous than the earlier

basalt Basalt (; ) is an 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 surface of a rocky planet or moon. More than 90 ...

s and

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 Amer ...

lavas.

El Parícutin — 1943−1952

The

volcano began as a

fissure A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word , which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes. Ground fissure ...

in a cornfield owned by a Purépecha farmer, Dionisio Pulido, on February 20, 1943. Pulido, his wife, and their son all witnessed the initial

eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often ...

of ash and stones first-hand as they ploughed the field. El Parícutin grew quickly, reaching five stories tall in just a week, and it could be seen from afar in a month. Much of the volcano's growth occurred during its first year, while it was still in the explosive pyroclastic phase. The nearby villages of Paricutín (after which the volcano was named) and San Juan Parangaricutiro were both buried in lava and ash. The residents relocated to nearby lands. At the end of the first phase, after roughly one year, the cinder cone had grown tall. For the next eight years El Parícutin would continue erupting, although this was dominated by relatively quiet eruptions of lava that would scorch the surrounding of land. The cinder cone's activity would slowly decline during this period until the last six months of the eruption, during which violent and explosive activity was frequent. In 1952 the eruption ended and Parícutin went quiet, attaining a final height of from the cornfield where it began. Like most cinder cones, Parícutin is believed to be a

monogenetic volcano A monogenetic volcanic field is a type of volcanic field consisting of a group of small monogenetic volcanoes, each of which erupts only once, as opposed to polygenetic volcanoes, which erupt repeatedly over a period of time. The small monogeneti ...

, which means that once it has finished erupting, it will never erupt again. Any new eruptions in the Michoacan-Guanajuato volcanic field will erupt in a new location. Three people died as a result of lightning strikes caused by the eruptions, but no deaths were attributed to the lava or asphyxiation.

Gallery

Image:Paricutin 30 612.jpg, Cinder cone in 1943 Image:Paricutin 30 613.jpg, 1943 eruption Image:paricutin1.jpg, Parícutin from Las Cabañas Image:paricutin2.jpg, San Juan Parangaricutiro Church Image:El Jorullo.jpg, Jorullo Cinder Cone

References

Parícutin at Volcano World
* ''Parícutin: The Volcano Born in a Mexican Cornfield'', Edited by James F Luhr and Tom Simkin, Phoenix AZ: Geoscience Press, 1993. The definitive collection of reports and documentary illustrations of the eruption and its effects up to the date of publication. * Peakbagger.co
Parícutin: Credits
Retrieved April 16, 2008. * Volcano World (El Jorullo)

Retrieved April 17, 2008.

Volcano World. Retrieved Apr. 16, 2008. *
"El Jorullo: Credits"
Popular Science Monthly. Retrieved Apr. 17, 2008.

Bartleby.com. Retrieved Apr. 17, 2008.

External links

Video documentary (eng/spa) Volcano Parícutin (4min)
{{DEFAULTSORT:Michoacan-Guanajuato volcanic field Volcanism of Mexico Volcanic fields Volcanoes of Guanajuato Volcanoes of Michoacán Natural history of Guanajuato Natural history of Michoacán