Abstract

CERVANTES-SOLANO, Miguel et al. An integrated magnetic survey of the Xitle volcano lava flows: archaeological implications on the abandonment of Cuicuilco. Bol. Soc. Geol. Mex [online]. 2019, vol.71, n.2, pp.397-411.  Epub Oct 30, 2019. ISSN 1405-3322.  https://doi.org/10.18268/bsgm2019v71n2a10.

The Xitle volcano is part of the Quaternary Chichinautzin volcanic field, located in the southern portion of the Valley of Mexico. The Xitle lavas were emplaced on the archaeological site of Cuicuilco, one of the first urban settlements of the Preclassic period in Mexico. This eruption had a great impact, since it caused great economic and social changes, favoring the consolidation of Teotihuacan as the dominant city in the Valley of Mexico. Available radiometric studies place the age of the eruption between 4000 to 1500 years BP (before present) and there is evidence that Cuicuilco abandonment was due to an eruption between 200 BC (Before Christ) and 200 AD (Anno Domini/ after Christ) without exact definition about the age of this event. Therefore, contributing to the accuracy of the age of the eruption continues to be of great interest. The results of new archaeomagnetic dating of rock samples from a sequence of lava flows from Xitle volcano located within the campus of the University of Mexico (UNAM) campus are presented below. A full geomagnetic vector and the field prediction model SHA.DIF.14K were used for such determinations. Two eruptive periods are identified, the first between 1742 and 1491 BC and the second, related to the eruption of Xitle volcano, between 79 BC and 595 AD. The age of the second period is compatible with the hypothesis of gradual abandonment of Cuicuilco and coincides with the accepted ages for the volcano᾿s most important eruptive period.

Keywords : Xitle; Archaeomagnetism; Cuicuilco; Valley of Mexico.