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A Devastating Plinian Eruption at Tungurahua Volcano Reveals Formative Occupation at ∼1100 cal BC in Central Ecuador

  • J-L Le Pennec (a1) (a2) (a3), G de Saulieu (a4), P Samaniego (a1) (a2) (a3), D Jaya (a5) and L Gailler (a1) (a2) (a3)...


Based on archaeological and radiometric constraints, previous studies have divided pre-Columbian times of Ecuador into a succession of cultural periods. The Paleoindian and Preceramic periods encompass the time from the first Amerindian occupation to about 4000 BC. The Formative period extends from ∼4000 to ∼300 BC, while the Regional Development (∼300 BC to ∼AD 700) and Integration periods predate the Columbian period, which starts in AD 1533 in Ecuador. The Formative cultural period is poorly known from earlier studies. Here, we bring the first documentation of Formative age occupation around Tungurahua Volcano, 120 km SW of Quito, and show that local settlements were devastated by a violent eruption around 1100 cal BC. Recent volcanological works combining lithostratigraphic, petrologic, and geochronologic analyses reveal that the steep-sloped Tungurahua edifice suffered a major Late Holocene flank failure. We show that the failure event resulted from a major explosive eruption triggered by massive magma intrusion inside the volcano. Decompression of the magma due to a flank collapse resulted in a violent, high-velocity directed blast explosion, which deposited charcoaland sherd-rich ash layers upon and near the volcano. Our 14C results range from 2225 ± 30 to 5195 ± 45 BP, but most cluster between 2640 ± 45 and 3195 ± 45 BP. A calibration analysis indicates that the event took place at ∼1100 cal BC, in the Formative period. We gathered 38 pottery sherds from 3 localities. The sherds show a diversity of size, shape, color, and ornamentation. Examination of pastes, surface finish, and firing indicates that our material shares many common features from site to site. The material from Tungurahua shares affinities with the Cotocollao tradition, which developed in the Quito region between 1500 and 500 BC, and with the Machalilla tradition (coastal region of Ecuador), with the occurrence of carinated bowls with punctuate decorations at 1500–1000 BC. Our study reveals that the ∼1100 cal BC Plinian eruption of Tungurahua Volcano is among the oldest known volcanic disasters in the Andes.


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Arellano, J. 1994. Loma Pucará, a Formative site in Cebadas valley, Ecuador. National Geographic Research & Exploration 10(1):118–20.
Arellano, J. 1997. Loma Pucará. Un asentamiento del Formativo tardío en el valle de Cebadas, Sierra central del Ecuador. Fronteras de Investigación 1:78100.
Arellano, J. 1999. Primeras evidencias del formativo tardío en la Sierra central del Ecuador. In: Ledergerber-Crespo, P, editor. Formativo Sudamericano: una reevaluación. Quito: Producciones Digitales UPS. p160–75.
Athens, JS. 1999. Volcanism and archaeology in the Northern Highlands of Ecuador. In: Mothes, P, editor. Actividad volcánica y pueblos precolombinos en el Ecuador. Quito: Abya-Yala editions. p 157–89.
Collier, D, Murra, J. 2007. Reconocimiento y Excavaciones en el Austro Ecuatoriano. Cuenca: Casa de la cultura ecuatoriana, núcleo del Azuay.
Eychenne, J, Le Pennec, J-L, Troncoso, L, Gouhier, M, Nedelec, JM. 2012. Causes and consequences of bimodal grain-size distribution of tephra fall deposited during the August 2006 Tungurahua eruption (Ecuador). Bulletin of Volcanology 74(1):187205.
Eychenne, J, Le Pennec, J-L, Ramon, P, Yepes, H. 2013. Dynamics of explosive paroxysms at open-vent andesitic systems: high-resolution mass distribution analyses of the 2006 Tungurahua fall deposit (Ecuador). Earth and Planetary Science Letters 361:343–55.
Fierstein, J, Nathenson, M. 1992. Another look at the calculation of fallout tephra volumes. Bulletin of Volcanology 54(2):156–67.
Grieder, T, Farmer, J, Hill, D, Stahl, P, Ubelaker, D. 2009. Art and Archaeology of Challuabamba, Ecuador. Austin: University of Texas Press.
Guillaume-Gentil, N. 2008. Cinq mille ans d'histoire au pied des volcans en Équateur. Terra Archeologica VI. Neuchâtel: SLSA/Infolio. 258 p.
Gurioli, L, Teresa Pareschi, M, Zanella, E, Lanza, R, Deluca, E, Bisson, M. 2005. Interaction of pyroclastic density currents with human settlements: evidence from ancient Pompeii. Geology 33(6):441–4.
Hall, ML, Mothes, PA. 2008. Volcanic impediments in the progressive development of pre-Columbian civilizations in the Ecuadorian Andes. Journal of Volcanology and Geothermal Research 176(3):344–55.
Hall, ML, Robin, C, Beate, B, Mothes, P, Monzier, M. 1999. Tungurahua Volcano, Ecuador: structure, eruptive history and hazards. Journal of Volcanology and Geothermal Research 91(1):121.
Jaya, DM. 2003. Volcanología del evento explosivo mayor del Tungurahua asociado al colapso de flanco en el Holoceno superior [Thesis Memoir (Engineering Geology)]. Quito: Escuela Politécnica Nacional. 141 p.
Le Pennec, J-L, Jaya, D, Samaniego, P, Ramón, P, Moreno, S, Egred, J, van der Plicht, J. 2008. The AD 1300–1700 eruptive periods at Tungurahua volcano, Ecuador, revealed by historical narratives, stratigraphy and radiocarbon dating. Journal of Volcanology and Geothermal Research 176(1):7081.
Lipman, PW, Mullineaux, DR, editors. 1981. The 1980 Eruptions of Mount St. Helens, Washington. US Geological Survey Professional Paper 1250. Reston: USGS. 844 p.
Lippi, R. 1998. Una exploración arqueológica del Pichincha occidental, Ecuador. Quito: Museo Jacinto Jijón y Caamaño.
Meggers, B, Evans, C, Estrada, E. 1965. Early Formative Period of Coastal Ecuador. The Valdivia and Machalilla Phases. Washington, DC: Smithsonian Institution.
Peccerillo, P, Taylor, SR. 1976. Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area, northern Turkey. Contribution to Mineralogy and Petrology 58(1):6381.
Porras, P. 1977. Fase Alausí. Revista de la Universidad Católica, año V, N°17, Sept. 1977. Quito: Pontifica Universidad Católica del Ecuador. p 89160.
Reimer, PJ, Baillie, MGL, Bard, E, Bayliss, A, Beck, JW, Blackwell, PG, Bronk Ramsey, C, Buck, CE, Burr, GS, Edwards, RL, Friedrich, M, Grootes, PM, Guilderson, TP, Hajdas, I, Heaton, T, Hogg, AG, Hughen, KA, Kaiser, KF, Kromer, B, McCormac, FG, Manning, SW, Reimer, RW, Richards, DA, Southon, JR, Talamo, S, Turney, CSM, van der Plicht, J, Weyhenmeyer, CE. 2009. IntCal09 and Marine09 radiocarbon age calibration curves, 0–50, 000 years cal BP. Radiocarbon 51(4): 1111–50.
Rodbell, DT, Bagnato, S, Nebolini, JC, Seltzer, GO, Abbott, M. 2002. A late Glacial-Holocene tephrochronology for glacial lakes in southern Ecuador. Quaternary Research 57(3):343–54.
Rostain, S. 2012. Between Sierra and Selva: landscape transformations in upper Ecuadorian Amazonia. Quaternary International 249:3142.
Samaniego, P, Le Pennec, J-L, Robin, C, Hidalgo, S. 2011. Petrological analysis of the pre-eruptive magmatic process prior to the 2006 explosive eruptions at Tungurahua volcano (Ecuador). Journal of Volcanology and Geothermal Research 199(1–2):6984.
Stuiver, M, Reimer, PJ. 1993. Extended 14C data base and revised CALIB 3.0 14C calibration program. Radiocarbon 35(1):215–30.
Valdez, F, Guffroy, J. 2009. Reconocimiento arqueológico en el sitio Rincón Amazónico. In: Duche Hidalgo C, Saulieu G. de. 2009. Pastaza Precolombino. p 1922.
Valdez, F, Guffroy, J, de Saulieu, G, Hurtado, J, Yepez, A. 2005. Découverte d'un site cérémoniel formatif sur le versant oriental des Andes. Comptes Rendus Palevol 4(4):369–74.
Villalba, M. 1988. Cotocollao: una aldea formativa del valle de Quito. Miscelánea antropológico ecuatoriano, Serie Monográfica 2. Quito: Museo del Banco Central del Ecuador.
Villarosa, G, Outes, V, Hajduk, A, Crivelli Montero, E, Sellés, D, Fernàndez, M, Crivelli, E. 2006. Explosive volcanism during the Holocene in the Upper Limay River Basin: the effects of ashfalls on human societies, Northern Patagonia, Argentina. Quaternary International 158(1):4457.


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