Abstract

RODRIGUEZ-PASCUA, Miguel Ángel et al. Paleoseismic and archeoseismic evidence of the Late Postclassic P'urhepecha symbols in Michoacán (Mexico). First historical seismic signaling?. Bol. Soc. Geol. Mex [online]. 2021, vol.73, n.2, 00012.  Epub Jan 31, 2022. ISSN 1405-3322.  https://doi.org/10.18268/bsgm2021v73n2a161220.

The pre-Hispanic Mesoamerican cultures of the Mexican highlands, and specifically the P'urepecha and Aztec empires (Late Post-Classic Period, 1300 - 1500 AD), experienced great destructive earthquakes that lft a mark on their society and determined both their spiritual rites and their urbanism. This paper studies several paleo-earthquakes that the P'urepechas experienced in Lake Pátzcuaro, usingpaleosismology techniques, as well as the existence of large basaltic blocks associated with their religious rites appearing in the hanging wall of two large surface ruptures of coseismic origin (normalfaults) that affected the geography of the lake itself. Paleoseoseismic studies suggest that several earthquakes of magnitude between M 6.5 and M 7 occurred withfault surface rupture and probably with a migration from the lake shore. In addition, these studies show that these earthquakes have been occurring since the Preclassic period (3000 BP). Later, the P'urepechas placed two large basalt blocks of more than 1 m3 in volume over the flanging wall of these faulting ruptures and carved their surface for spiritual purposes. In later times during the Spanish conquest, a large Maltese-style Christian cross was carved, which would correspond to the process of Christian evangelization throughout the 16th century in the area of Michoacán, thus reinforcing the spiritual significance of these blocks. In any case, we are facing one of the oldest human manifestations of the effects of earthquakes on ancestral cultures.

Keywords : P'urepecha Civilization; paleoearthquake; paleoseismology; seismic signalization.