An updated catalog of pre-hispanic archaeomagnetic data for north and central Mesoamerica: Implications for the regional paleosecular variation reference curve

Ana Ma. Soler-Arechalde^1,*, Cecilia Caballero-Miranda¹, Ma. Luisa Osete-López²,

Verónica López-Delgado³, Avto Goguitchaichvili⁴, Alan Barrera-Huerta⁵, Jaime Urrutia-Fucugauchi¹

¹Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, Coyoacan, CDMX, Mexico.

²Facultad de Ciencias Físicas, Departamento de Física de la Tierra, Astronomía y Astrofísica. Universidad Complutense. Plaza de Ciencias,1. Ciudad Universitaria. 28040, Madrid, Spain.

³Posgrado en Ciencias de la Tierra. Instituto de Geofísica. Universidad Nacional Autónoma de México. Campus Morelia. Antigua Carretera a Pátzcuaro 8701, Ex Hacienda de San José de la Huerta, 58190 Morelia, Michoacán, Mexico.

⁴Instituto de Geofísica. Universidad Nacional Autónoma de México. Campus Morelia. Antigua Carretera a Pátzcuaro 8701, Ex Hacienda de San José de la Huerta, 58190, Morelia, Michoacán, Mexico.

⁵Posgrado en Estudios Mesoamericanos. Universidad Nacional Autónoma de México. Ciudad Universitaria, 04510, Coyoacan, CDMX, Mexico.

*This email address is being protected from spambots. You need JavaScript enabled to view it. 

Abstract

Despite the immense cultural heritage of Mesoamerica, there is still no reference archaeomagnetic curve available for Central Mexico and adjacent areas. The present research has two simultaneous objectives: to obtain finer characteristics of the geomagnetic field elements over archaeological past, and to build up a reliable regional archaeomagnetic dating tool for the time span of 350 BC. to 1500 AD. For these purposes, 72 previous were compiled and analyzed with 40 new data selected from unpublished reports and theses performed in the paleomagnetic laboratories of the Geophysics Institute of UNAM (CDMX and Morelia). Most of the samples carry thermo-remanent magnetization, 31 cases were unburned stuccos, and 3 mural paintings carrying detrital or pictorial remanent magnetization. A total of 112 archaeomagnetic directions constitute the core of the updated catalogue. Special effort should be paid for to the time intervals of 500 BC.—AD. 200 and AD. 1200–325 where there is a major lack of reliable archaeomagnetic results. The present paleosecular variation curve agrees reasonably well with the fluctuation observed in the SW United States area. The differences in the intervals between AD. 600–720, AD. 850 and 1000 and AD. 1200–1325 may be rather attributed to the lack of reliable data than to local non-dipole field. It is urgent to gather a greater number of high-quality data supported by radiome­tric ages to improve the reference curve in both regions.

Keywords: Archaeomagnetic dating, geomagnetic field, paleosecular variation, central Mexico.