Caracterización de la fuente lítica Jagüelito, Pampa de Canota (Mendoza, Argentina)

This paper presents a characterization of the Jagüelito quarry–workshop, located near the Pampa de Canota (northwestern Mendoza, Argentina). The exploitation of this source is discussed within a framework of technological organization and lithic production systems. Raw materials are characterized with macroscopic and petrographic analysis. A general characterization of the sample (n=85) was carried out that took into account aspects such as raw material, size, weight, and the reduction sequence. The available stones have a porphyritic structure (rhyolites/dacites) and five subtypes were identified. The results show that the initial stages of knapping were carried out at the source and expedient artifacts were discarded. Material selection and initial preparation may have involved transporting lithic material as well as making and discarding tools at other sites in the region. The analysis of this material from the source and the data from regional sites suggest that people employed expedient and conservative technological strategies. Although all the reduction stages are represented at the source, this source has been recorded at other sites. This shows that, in many cases, the reduction sequence continued and ended elsewhere, where these raw materials were integrated into lithic production sequences.Se presenta una caracterización de la cantera-taller Jagüelito, localizada en las cercanías de la Pampa de Canota (NO de Mendoza, Argentina). Se discute la explotación de esta fuente desde la organización tecnológica y los sistemas de producción lítica. Se caracteriza la materia prima disponible mediante un análisis macroscópico y petrográfico. Se realiza una caracterización general de la muestra (n=85), teniendo en cuenta aspectos como la materia prima, el tamaño, el peso y las secuencias reductivas. Las rocas disponibles son de estructura porfírica (riolitas/dacitas) entre las cuales se identificaron cinco subtipos. Los resultados sugieren que en la fuente se realizaron actividades de talla iniciales y se descartaron artefactos de formatización sumaria. La selección y desbaste primario podría, además, haber implicado el transporte de soportes y la confección y descarte de instrumentos en otros sitios de la región. El análisis lítico de la fuente y los datos procedentes de sitios regionales sugieren la implementación de estrategias tecnológicas expeditivas y conservadas. Si bien, en la fuente se encuentran representadas todas las etapas reductivas, estos recursos han sido registrados en sitios que evidencian que en muchos casos la secuencia reductiva continuó y finalizó fuera de la fuente donde se integraron estas materias primas a sistemas secuenciales de producción lítica

The center cannot hold: A Bayesian chronology for the collapse of Tiwanaku.

The timing of Tiwanaku's collapse remains contested. Here we present a generational-scale chronology of Tiwanaku using Bayesian models of 102 radiocarbon dates, including 45 unpublished dates. This chronology tracks four community practices: residing short- vs. long-term, constructing monuments, discarding decorated ceramics, and leaving human burials. Tiwanaku was founded around AD 100 and around AD 600, it became the region's principal destination for migrants. It grew into one of the Andes' first cities and became famous for its decorated ceramics, carved monoliths, and large monuments. Our Bayesian models show that monument building ended ~AD 720 (the median of the ending boundary). Around ~AD 910, burials in tombs ceased as violent deaths began, which we document for the first time in this paper. Ritualized murders are limited to the century leading up to ~AD 1020. Our clearest proxy for social networks breaking down is a precise estimate for the end of permanent residence, ~AD 1010 (970-1050, 95%). This major inflection point was followed by visitors who used the same ceramics until ~AD 1040. Temporary camps lasted until roughly ~AD 1050. These four events suggest a rapid, city-wide collapse at ~AD 1010-1050, lasting just ~20 years (0-70 years, 95%). These results suggest a cascading breakdown of community practices and social networks that were physically anchored at Tiwanaku, though visitors continued to leave informal burials for centuries. This generation-scale chronology suggests that collapse 1) took place well before reduced precipitation, hence this was not a drought-induced societal change and 2) a few resilient communities sustained some traditions at other sites, hence the chronology for the site of Tiwanaku cannot be transposed to all sites with similar material culture