The hunter-gatherers of Abra del Toro rock shelter, northwestern Argentina, suffered the effects of the large 4.2 ka Cerro Blanco eruption

JOSE-LUIS FERNANDEZ-TURIEL; CARBONELLI JUAN PABLO; BELOTI LÓPEZ DE MEDINA, CARLOS

Congreso; EGU General Assembly 2023; 2023

There is a dearth of information regarding prehistoric foraging societies from the intermontanelongitudinal valleys of the South-Central Andes. Due to the intense anthropization of thelandscape or the scarce research efforts on prehistoric populations of hunter-gatherers in theintermontane valleys of the Andes, occupation sites have been found on very few occasions.However, new perspectives in the Abra del Toro rock shelter in the Yocavil Valley (Catamarcaprovince, Argentina) have opened up from recent and ongoing excavations. This rock shelter is thefirst archaeological case in which it is possible to analyze the relationship between a large-scalenatural catastrophe and the prehistoric populations living in the Andean intermontane valleys ofthe southern Central Andes. This rock shelter's stratigraphy and archaeological remains containthe record of interactions between human communities and volcanism. The stratigraphic recordof the rock shelter shows a 1-m-thick volcanic ash deposit formed by aeolian transport fromprimary outer ashfall deposits. Geomorphological and sedimentological context, texture, glass andmineral content, whole-rock chemical composition, and radiocarbon dating prove that the tephrawas derived from the 4.2 ka BP eruption of the Cerro Blanco Volcanic Complex in southern Puna(NW Argentina). This volcanic eruption is the largest documented in the world in the last fivethousand years and covered the surroundings of the archaeological site with an ash layer ofapproximately 1 meter thick. The stratigraphic sequence of the Abra del Toro rock shelter allowsus to hypothesize that there were three main occupational moments: two hunter-gatherermoments, separated by the record of the large volcanic eruption, and a subsequent agro-potteryperiod (Carbonelli et al. 2022. J. Archaeol. Sci. Rep. 45, 103629). The rock shelter after the eruptionremained in the memory of the hunter-gatherer groups. Good visibility, accessibility, andproximity to water were attributes of this space that made it possible for it to be re-occupied afterthe eruptive event. Our next objective is to reconstruct, using proxy analysis, how thepaleoenvironment was in the intermontane valleys before and after the eruption. The evidence ofthis Mid-Holocene catastrophic volcanic event in the Abra del Toro rock shelter opens thepossibility of knowing its impact on the contemporary hunter-gatherer community and drawingconclusions for similar future volcanic crises.