Michoacan-Guanajuato volcanic field, Paricutin region, Zamora volcanic field.
19.48 N, 102.25 W,
summit elevation 3860 m
The Michoacán-Guanajuato volcanic field contains over 1400 vents, including the historically active cinder cones of Parícutin and Jorullo. The volcanic area is distinct from other regions of Mexico because it contains cincer cones rather than stratovolcanoes.
Cinder cones in Michoacán-Guanajuato volcanic field are randomly spaced and indicate no preferred orientation. They occur at relatively low elevations as most cones formed either on alluvial plains or low on the flanks of eroded shield volcanoes.
The density of volcanoes in the Michoacán-Guanajuato volcanic field is 2.5 volcanoes per 100 sq km (1040 vents per 40,000 sq km). The highest density of 11 vents per 100 sq km is found in the Paricutin region (141 vents per 1250 sq km).
1943-52 Eruption of Paricutin
Paricutin was born on February 20, 1943 when a fissure opened on the lands of Rancho Tepacua. At 10:00 hr subterranean noises were heard and at 16:00 hr thunderous noises accompanied the opening of the first fissure. The earth was described as rising like a wall 1 m high, 10 m long, and 2 m wide. by midnight on the first day the cone at Paricutin had reached a height of 6m.
By afternoon of 21st February a 50 m high cone had formed and was ejecting bombs 500 m high, and for a distance of 300-400 m from the vent. A lava flow was visible early morning of 22nd February extending north through cornfields.
Explosions were heard 350 km away. By the end of the first year the volcano had reached 275 m high.
On 24th April 1944 an unusual light phenomenon was observed at the cone. It was described as "searchlights playing out of the crater". By the end of the eruption's second year in February 1945 the main phase of activity was finished.
Paricutin stopped erupting on 4th March 1952, however earthquakes continued to be felt near the volcano until September 1952.
1759-1774 eruption of Volcan El Jorullo
Subterranean noises were first heard in late June of 1759, increasing to the level of cannon shots by 17th September. On 29th September several earthquakes were felt and a dark cloud erupted from Cuitinga Creek. Phreatic and phreatomagmatic activity occurred in the initial stages of the eruption and covered the surrounding area with sticky mud. Incandescent bombs began to be ejected on 8th October 1759. Violent eruptions continued through 1764, the year of greatest activity, and lesser eruptions until 1774.
Lava erupted from a NE-SW-trending line of five cinder and lava cones separated by 3 km along Cuitinga Creek. The eruption centres included main cone of Jorullo, a single breached cone to its northeast (Volcan del Norte), and three breached cones to the southwest (unnamed, Volcan de Enmedio, Volcan del Sur).
The main cone of Jorullo (18.97 N, 101.72 W) rises 350 m above its surroundings to an elevation of 1,220 m.
Valle de Santiago 1050
Cerro el Jabali 1880 BC
Valle de Santiago (La Alberca) 2050 BC?
Cerro el Metate 2750 BC
Cerro la Taza 6480 BC
Hoyo el Huanillo 7350 BC