The Los Tuxtlas Volcanoes are an aberration on Mexico´s Gulf Coastal Plain. The volcanoes are separated from the
nearest volcano in the belt running across the spine of Mexico  to the west by about 230 km, and from the Central
American Volcanic Belt to the southeast by over 300 km.

The Tuxtlas have drawn attention because of this anomalous setting and because it
contains San Martin Tuxtla volcano, one of Mexico´s recently active volcanoes.

The eruptions creating Los Tuxtlas apparently bridged  two geological ages, with most of the Sierra de Santa Marta
having been dated to the Pliocene (app. 5-2 million years ago), with an overlay of the San Martin volcanoes having been
dated to the late Pleistocene, beginning app. 2 million years and lasting to the present. The last certified volcanic eruption
occurred in 1793.

There are dozens of named volcanoes in Los Tuxtlas, best known are San Martin Tuxtla, Cerro Santa Marta, Cerro Mono
Blanco, San Martin Pajapan and Cerro El Vigia. (Cerro means hill in Spanish).
There are basically two types of volcanoes in Los Tuxtlas, cinder cones and shield volcanoes.

Shield volcanoes
The major Los Tuxtlas volcanoes are shield volcanoes. They are built almost entirely of fluid lava flows. Flow after flow pours
out in all directions from a central summit vent, or group of vents, building a broad, gently sloping cone of flat, domical shape,
with a profile much like that of a warrior's shield. They are built up slowly by the accretion of thousands of highly fluid lava
flows called basalt lava that spread widely over great distances, and then cool as thin, gently dipping sheets. Lavas also
commonly erupt from vents along fractures (rift zones) that develop on the flanks of the cone. Some of the largest volcanoes
in the world are shield volcanoes.

Cinder cones
Many of the hills surrounding Catemaco are cinder cones. They are built from particles and blobs of congealed lava ejected
from a single vent. As the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as
cinders around the vent to form a circular or oval cone. Most cinder cones have a bowl-shaped crater at the summit and
rarely rise more than a thousand feet or so above their surroundings.
Source: US Geodesic Service
Los Tuxtlas put the San Andreas Fault to shame. The area is a hodgepodge of fault lines in all directions.
The San Martin side is much younger than the rest, and the chart makes it obvious how lava flow closed off the then valley of
Catemaco and turned it into a lake.
CENAPRED, the Mexican disaster prevention agency, considers the San Martin area a high volcanic risk zone, but only began
monitoring the volcano in 2007. The actual risk zones are in the north of the area, so I will not lose any sleep
types of local volcanoes
the volcanic field
the fault lines
risk factors
extinct volcanoes around Catemaco
Volcanoes of Los Tuxtlas
links
The ecotourism group in Ruiz Cortines offers all day guided trips to the top of the volcano, including a 3 hour climb.
Otherwise closest access is from Nacimiento de Xogapan, north of Santiago Tuxtla.

Each year, during easter week, young people from the Santiago Tuxtla form a procession to climb San Martin to collect a
prized flower, which only seems to grow there. On their return, the flowers are blessed in church and retained in their
homes to provide protection from the strong winds occuring in spring.

Año tras año, varios ciudadanos de Santiago Tuxtla, señores, señoras, niños,pero en su mayoría jóvenes, realizan un
recorrido al Volcán de San Martín para ir en busca del Arrayán, un arbusto que crece muy cerca del cráter.

Cabe mencionar que se hace una misa antes de realizar el recorrido, aunque muchos desean irse desde antes, al
terminar la misa aproximadamente a las 11:00 pm del Martes de Semana Santa, se inicia el recorrido, donde los
jóvenes van equipados con lámparas, provisiones de agua y algo de comida, y un buen abrigo, ya que en la cima del
San Martín por lo general hace mucho frío. Se hacen muchos grupos, cada uno encabezado por alguien que conoce
bien el camino al Volcán.

Una vez que llegan a la famosa Cruz, la gente se toma un descanso para tomar algo agua y probar algo de alimento, o
solo para recuperar energías. A partir de aquí el cráter se encuentra cerca.

Ya el miércoles de Semana Santa, aproximadamente a las 10:00 am, se espera la llegada de los grupos en la iglesia,
donde colocan el Arrayán para que sea utilizado el Jueves Santo en el "Aposentillo". Muchos guardan unas ramas de
todas las que trajeron, y se las llevan a su hogar, donde las conservan para incendiarlas en los días en los que la
tormentas en esta ciudad son muy fuertes.
Source:  Electroeyes' SantiagoTuxtla web site   (dead)                    
The San Martín Tuxtla volcano is part of the Tuxtla volcanic field and is a broad shield volcano. The summit and flanks
of this 5701 feet high volcano are dotted with more than 250 pyroclastic cones and craters.

The volcano is named after the first sailor on Cortez's invasion fleet to sight the mountain. In the Nahuatl
language the volcano is named Titépetl (Cerro de la Lumbre o del Fuego, Fire mountain), and some say it actually
showed a little bit of a snowy top in 1997, although the last official record is from the late 1900's. The suffix of
"Tuxtla" is commonly used  to distinguish it from the San Martin Pajapan volcano

The height of the volcano is a mystery. My last aeronautical chart shows San Martin at 5701 feet, that´s 1737
meters, INEGI says 1680m, CONANP 1650m, PROFEPA 1764m &  IBUNAM 1700m. I´ll stick to my pilot settings.

The two largest historical eruptions took place in 1664 and 1793.

The 1793 eruption occurred from two cinder cones in the 1-km-wide summit crater and produced widespread ashfall
and lava flows that extended 3.5 km down the NE flank.  
An alleged eruption in the early 1500's may have caused settlers near the volcano to have fled and then to have
formed the forerunner of what is now the city of San Andrés Tuxtla.

Other pre hispanic eruptions are supposed to have created havoc with local civilizations from the Olmecs to the
Maxacapan settlements.

Supposedly around 600 AD, Cerro Nixtamalapan, a few kilometers northeast of Catemaco city blew up and
contributed significant lava flow to the edges of Laguna Catemaco which is still visible in the La Punta area.

2 other very disputable minor seismic events may have occurred in 1838 and 1932.
Volcano San Martin, pick your own height: 1731m,
Cerro Buena Vista  - on way to Dos Amates,
Cerro Mata Larga - near estacion biologica,
Cerro Vigia - near estacion biologica (530m?),
Cerro Cintepec, 670 m,
Cerro Mezcalapa,
Cerro Sihuapan,
Cerro de la Muerte,
Cerro in Monte Pio,  look quick it's being dismantled,

Baxintepec
Tzompaxoltepec
Matzaltepec
Baycaltepec
Visiting the Volcano
San Martin Tuxtla volcano
some names of volcanoes
Cerro Santa Marta, pick your own height: 1750m, 1650, 1720, 1500 meters
Volcano Yohualtajapan
Cerro El Campanario - 1540 or maybe 1180 m
Cerro  Blanco - 1380m ?
Cerro Cintepec - 670m
Cerro Pico de Aguila
Cerro Vigia
Cerro La Campana
Cordon Pelon
Filo Península de Moreno, Bastonal-Yohualtajapan - 1640m
Cerro Platanillo - 1,550 m
Sierra Santa Marta volcanoes
The Sierra Santa Marta is actually composed of several named volcanic peaks. Volcano Santa Marta appears to be the
remaining caldera of a much larger volcano, as is evident in the photo below created with the tilt technique on Google Earth.

This extinct volcano is of the broad shield type, tops out close to 5800 feet, about 1750 meters. (there is no authority on its
actual height), and is hard to visually separate on the ground from neighboring tall volcanic peaks in the Sierra Santa Marta,  
Cerro Mezcalapa, Cerro Sihuapan, Cerro Platanillo (1,550 m), Cerro de la Muerte, Filo Península de Moreno, and  
Bastonal-Yohualtajapan (1,640 m)
some volcano names
The volcano, known in Spanish as Cerro San Martin Pajapan, is the most southern volcano in the Los Tuxtlas volcanic
field.

Aside from a mention of this extinct volcano as a sacred site, very little internet information is available about  this
volcano. Allegedly it is the home of chaneques (goblins) who frequent its hill side caves

The municipios of Tatahuicapan and Pajapan control access to the volcano, and had graciously extended protected
status to the areas that cows can´t reach, even before the top of the old volcano was declared part of the Los Tuxtlas
Biosphere Reserve. Since 1998, 7.3 square miles of the volcano are protected as a nucleus of the Biosphere.

The height of the volcano is disputed, so pick your own height: 1,250, 1200, 1145, 1160m, about 4000 feet.

Geologically, this is probably the oldest volcano in Los Tuxtlas, dating from about 7 million years ago.

A famous Olmec statue was recovered from its peak. The statue is now housed in the Xalapa Museum of Anthropology.
Local residents demanded its return for almost 100 years and have now been pacified with a replica in Tatahuicapan,
which continues to attract worshippers.
San Martin Pajapan
Cerro El Vigia
This is the volcano that dominates the skyline of the city of Santiago Tuxtla.

The "Lookout Hill" (in Spanish) is variously described as between 800 and 1000 meters high. In the Nahuatl language the
hill is called Cihuatépetl (Hill of the woman or old lady). Its last eruption is calculated to have occurred 2.2 million years
ago, but its more recent history makes it one of the most significant hills in Los Tuxtlas.

The Olmec civilization formed a major center in Tres Zapotes more than 3000 years ago on the lower western flanks of
the volcano. One of the giant Olmec heads and numerous other artifacts were unearthed on its flanks. And some
Mormons claim the hill to be the ancient battle site of Cumorah.

Recent excavations at Totogal,also in the western foothills demonstrate a large population center before and after the
Aztec invasion of 1465+/-.
Catemaco is surrounded by both the San Martin and Santa Marta volcanoes.

The  nearby Cerro Mono Blanco, "White Monkey Mountain", is possibly the most famous hill in Los Tuxtlas because of its
association with witchcraft.

The hill is located about 4km north of the city of Catemaco and is a dominant feature for travellers arriving from the South.
fly over the Sierra Santa Marta
see some volcanoes of Los Tuxtlas
an old list, probably with many dead links.