Imagine a day in 245 AD. Xitle suddenly appeared. The people of Cuicuilco could not have known what was coming.
Xitle is a monogenetic volcano in the Ajusco range. It sits in Cumbres del Ajusco National Park. We are in the Tlalpan borough. This is the southwestern part of Mexico City. Xitle is an ash cone volcano. It has a conical form and a round base. The altitude is about 300 meters. The slope is between 30 and 40 degrees.
Xitle erupted violently for 70 years. The eruptions began around 245 AD and lasted until 315 AD. Radiocarbon dating confirms this timeline. The eruption had major consequences. It formed the Pedregal de San Ángel lava fields. These fields are south of the Mexican Federal District. The lava flow extended about 80 square kilometers.
Cuicuilco was one of Mesoamerica’s most advanced cities. Xitle destroyed it. Lava covered everything. Some people believe survivors fled. They contributed to the rise of Teotihuacan. This city was growing in power at the time. The destruction marked a new era in Mesoamerican history.
Unlike Pompeii, Xitle did not bury Cuicuilco in ash. Xitle emitted a giant lava flow. This lava solidified into iron-hard rock. Today, we call it Pedregal. It covers a large area in southern Mexico City.
The name Xitle comes from Nahuatl. Xictli means navel. The mountain remained important for a thousand years. It was an icon until the end of the ancient period.
Archaeologists found charcoal under the lava layer. Radiocarbon dating showed the charcoal formed between 245 and 315 AD. This confirmed when Xitle erupted. It also helped determine when Cuicuilco civilization thrived.
Originally, Cuicuilco was thought to be from the Pre-Classic Period. But the lava flow’s age revealed it was active during the Classic Period. This new timeline helps us understand population movements in Mexico.
Cuicuilco was one of the earliest metropolitan cities in the New World. During Xitle’s eruption, the population declined. The eruption was a major cause.
One pyramid survived. It is a circular pyramid. Designs of an agricultural system are visible. The lava flowed around it. Archaeological digs around this site improved our understanding. They helped uncover the buried city.
Sadly, urbanization has destroyed much of the Cuicuilco pyramid. Mexico City has grown across the region. But studies of the Xitle lava flow continue. Researchers focus on young volcanic eruptions. They try to date the lava flow directly. The National University of Mexico has a special connection. Part of the campus is built on the lava flow.
Today, Xitle is largely covered in trees and wildlife. It is a popular site for tours and hikes. Religious processions have visited the site for centuries. The Feast of the Holy Cross on May 3 is a prominent celebration. The volcano is still an important presence.