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Volcanism, Ecology and Culture: A Reassessment of the Volcán Ilopango TBJ Eruption in the Southern Maya Realm

Published online by Cambridge University Press:  20 January 2017

Robert A. Dull ,
John R. Southon  and
Payson Sheets
Robert A. Dull
Affiliation:
Department of Geography, University of California, Berkeley, CA 94720
John R. Southon
Affiliation:
Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94550
Payson Sheets
Affiliation:
Department of Anthropology, University of Colorado, Boulder, CO 8030
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Abstract

The Tierra Blanca Joven (TBJ) eruption of the Ilopango caldera in central El Salvador was one of the largest Holocene volcanic events in Central America, and its ecological and cultural impacts were felt throughout El Salvador and adjoining areas of Guatemala and Honduras. Early radiocarbon measurements established a ca. A. D. 260 ± 114 calendar date for the eruption. However, a reevaluation of the original 14C dates, in addition to new AMS 14C assays, shows that the TBJ eruption occurred at least a century and a half later than originally estimated. The revised 14C composite supports an Early Classic Period calendar date for the eruption: 1 sigma = A. D. 421(429)526; 2 sigma = A. D. 408(429)536. A review of archaeological settlement, ceramic, and radiocarbon evidence from sites throughout the area of greatest devastation reveals a large-scale demographic collapse following the event. We believe that the population crash was caused both by the biophysical effects of the eruption and by the resulting disarticulation of the "Miraflores" cultural-economic sphere. The affected areas of El Salvador and south-eastern Guatemala did not completely recover until the seventh century A. D.

Resumen

Resumen

La erupción del Tierra Blanca Joven (TBJ) de la caldera de Ilopando en la porción central de El Salvador, fue uno de los eventos volcánicos más grandes del Holoceno en Centroamérica. El Salvador y zonas limítrofes de Guatemala y Honduras resintieron el impacto ecológico y cultural de este evento. Con base en los fechamientos de radiocarbono con que se contaba previamente la erupción se dató hacia 260 + 114 d. C. Sin embargo, una reevaluación de esas fechas además de otras recientemente procesadas, muestran que la erupción del TBJ ocurrió cuando menos siglo y medio después de lo que se había calculado originalmente. De esta manera, se fundamenta la adscripción temporal de la erupción en el periodo Clásico Temprano: 1 sigma = 421 (429) 526 d. C.; 2 sigma = 408 (429) 536 d. C. Una revisión de los asentamientos arqueológicos, la cerámica y las fechas de radiocarbono de varios sitios en el área que sufrió la mayor devastación, en el occidente de El Salvador y el sureste de Guatemala, evidencian un colapso demográfico a gran escala después del evento. La mayoría de las personas que habitaban en un área de 1000 km2 al occidente de la caldera del Ilopango -incluyendo el valle de San Salvador y partes del valle de Zapotitán- deben haber perecido instantáneamente a causa del impacto de materiales piroclásticos; quienes vivían más al occidente, en la cuenca del Río Paz y en la costa suroeste de El Salvador, probablemente abandonaron los pueblos a causa del colapso agrícola, el hambre y las enfermedades. En el sureste de Guatemala, donde los efectos biofísicos de la erupción no fueron tan severos, al parecer el decremento poblacional se debió a la desarticulación resultante de la esfera económico-cultural Miraflores. Los desplazados por el desastre que migraron hacia el norte, posiblemente contribuyeron al crecimiento de la población rural del valle de Guatemala y del centro urbano de Copán, Honduras. Las áreas que resultaron afectadas por el evento volcánico en El Salvador y el sureste de Guatemala lograron recuperarse hasta el siglo VII d. C.

Type
Articles
Information
Latin American Antiquity , Volume 12 , Issue 1 , March 2001 , pp. 25 - 44
Copyright
Copyright © Society for American Archaeology 2001

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