Archaeologists working in the Valley of Mexico have announced a breakthrough in dating methodology using Mica-Fission-Track refinement. This technique allows for the precise dating of volcanic tuff blocks used in the foundations of early Mesoamerican ceremonial centers with a resolution of plus or minus one year.
The study, published in the Journal of Archaeological Science, applied this method to the earliest layers of Cuicuilco, revealing that the site underwent a massive construction surge immediately following a major eruption of the Xitle volcano. This precision allows researchers to synchronize archaeological sequences with volcanic events and paleoclimate records with unprecedented accuracy, resolving long-standing disputes regarding the chronology of the Pre-Classic period.