Depopulation of the Northern Border of Mesoamerica during the Early Postclassic: Evidence from the Reappraisal of Archaeomagnetic Data
Por:
Pimentel A.G., Goguitchaichvili, Avto, Torreblanca, Carlos, Kravchinsky, Vadim, Cervantes, Miguel, Garcia, Rafael, Cejudo, Ruben, Bautista, Francisco, Morales, Juan
Publicada:
1 dic 2022
Resumen:
The Mesoamerican Postclassic and Epiclassic were periods of drastic
change and transformation related to social, political and economic
aspects as well as settlement patterns. Mexico's northern boundary
expansion, rise, and subsequent demise is a matter of debate which
remains essentially unsolved. Possible causes include climatic changes,
landscape degradation or prolonged bellicose relations with nomadic
groups. Still, no consensus exists on why such apparent instability and
decline occurred at major archaeological settlements on the northern
Mesoamerican border, also known as the septentrional frontier. The
scarcity of absolute chronological constraints is definitively a
handicap that impedes the assessment of northern Mesoamerica's
development from its apogee to its decline. The archaeomagnetic method
has been used during the last decades to analyze burned archaeological
artifacts belonging to Mesoamerica's north and central-west frontiers,
including different Mexican states. Namely, high-resolution studies were
carried out at Aguascalientes (El Ocote), Guanajuato (El Coporo, Lo de
Juarez and Plazuelas), Jalisco (Cerro de Los Agaves, La Palma and El
Palacio de Ocomo) and Zacatecas (La Quemada). It was successfully proved
that archaeomagnetic dating might greatly contribute to refining the
chronology and development of major pre-Hispanic settlements. These
studies were based on available geomagnetic curves at the time of
publication. However, global geomagnetic models have experienced
substantial improvement with the development of local/regional reference
archaeomagnetic curves during the last few years. Hence, the need arises
for a critical reassessment of reported age intervals and corresponding
chronological contexts. Updated archaeomagnetic ages are recalculated
considering the geomagnetic models SHA.DIF.14K and SHAWQ.2K as well as
the two regional paleosecular variation curves for Mesoamerica. A
bootstrap resampling method is used to obtain an optimal age range for
each studied structure. These new absolute chronologies indicate that
the last fire exposure of the vast majority of the analyzed artifacts
unequivocally corresponds to the Mesoamerican early Postclassic related
to the depopulation stage apparently caused by environmental changes.
Filiaciones:
Servicio Arqueomagnetico Nacional, Instituto de Geofísica, Universidad Nacional Autónoma de México (UNAM), Campus Morelia, Morelia, 58190, Mexico
Geophysics, Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada
Delegación INAH Zacatecas, Zacatecas, 98000, Mexico
Laboratorio Universitario de Geofísica Ambiental, Centro de Investigaciones en Geografía Ambiental, Universidad Nacional Autónoma de México (UNAM), Morelia, 58190, Mexico
gold, All Open Access; Gold
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