Se presentan los resultados de fluorescencia de rayos-X realizados a 12 artefactos provenientes de contextos funerarios Chinchorro, Arica, norte de Chile, focalizándose la discusión en el manganeso (Mn). La muestra con mayor concentración de Mn fue analizada con espectrometría Raman, para avanzar en la identificación estructural del cromóforo negro correspondiente. Todos los artefactos dieron positivo para la presencia de Mn con un rango de 1,11%-63,66%, considerándose antrópico sobre 2% (83,33% del total) y el pigmento analizado fue identificado como criptomelano y goetita.

The history of maize in Central America and surrounding areas has implications for the slow transition from hunting and gathering to agriculture. The spread of early forms of domesticated maize from southern Mexico across Mesoamerica and into South America has been dated to about 8,700–6,500 years ago on the basis of a handful of studies relying primarily on the analysis of pollen, phytoliths, or starch grains. Recent genomic data from southern Belize have been used to identify Archaic period south-to-north population movements from lower Central America, suggesting this migration pattern as a mechanism that introduced genetically improved maize races from South America. Gradually, maize productivity increased to the point that it was suitable for use as a staple crop. Here we present a summary of paleoecological data that support the late and uneven entry of maize into the Maya area relative to other regions of Central America and identify the Pacific coastal margin as the probable route by which maize spread southward into Panama and South America. We consider some implications of the early appearance of maize for Late Archaic populations in these areas; for example, with respect to the establishment of sedentary village life.

Se caracterizó mediante análisis de fluorescencia de rayos X portable (pXRF) un conjunto de obsidianas (n = 142) del sitio San Gregorio Atlapulco, en Xochimilco, Ciudad de México, procedentes de los niveles precerámicos, a través del análisis de 10 elementos químicos (Mn, Fe, Zn, Ga, Th, Rb, Sr, Y, Zr, Nb); esto nos permitió conocer la composición elemental de cada uno de los artefactos para posteriormente efectuar comparaciones con obsidianas de yacimientos sistemáticamente muestreados. Los resultados indican una amplia dominancia de la subfuente de Soltepec en Otumba (94%), además de otras dos fuentes menores que incluyen a Pachuca. Lo anterior tiene implicaciones importantes sobre los procesos de interacción de los grupos precerámicos del Holoceno medio en la Cuenca de México, y permite vislumbrar la importancia de la obsidiana de Otumba para el período denominado Arcaico, y la formación de redes de intercambio tempranas que continuarían durante el período Formativo.

Despite the abundance of lithic debitage at preceramic sites in the Maya Lowlands, these data have rarely been studied in detail. We analyzed the chipped chert debitage from Caye Coco and Fred Smith, two Archaic period sites in the Freshwater Creek drainage of northern Belize, to evaluate strategies of lithic raw material procurement, stone tool production, and tool use. The technological and use-wear analyses of the debitage demonstrate that the sites’ inhabitants procured most of their tool stone from the Northern Belize Chert-bearing Zone (NBCZ) and relied on hard-hammer percussion to produce flakes for use as expedient tools and some crude bifaces and unifaces. Although similar patterns of raw material procurement and tool production are demonstrated at both sites, some differences exist, including bipolar reduction at Caye Coco. Based on use-wear analysis, the debitage at the island site of Caye Coco was primarily used for working wood, shell, and hard contact materials and for digging soil. On the shore at Fred Smith, most use-wear is consistent with working wood, plants, and hard contact materials, as well as digging soil. For both sites, analyses suggest the increasing importance of a horticultural subsistence strategy with reduced mobility and reliance on some cultigens that were locally produced.

Archaeological studies at Coxcatlan Cave in the Tehuacan Valley of southern Puebla, Mexico, have been instrumental to the development of the chronology for the region and for our understanding of the origins of food production in the Americas. This article refines the Preceramic chronology of the Tehuacan Valley by presenting 14 new accelerated mass spectrometry (AMS) radiocarbon ages from faunal bone samples uncovered from early depositional levels of the rock shelter. Although bones associated with the El Riego (9893–7838 cal BP), Coxcatlan (7838–6375 cal BP), and Abejas (6375–4545 cal BP) phase zones of the cave yielded ages similar to those of the previously proposed chronology for the region, bones from the Ajuereado phase zones at the base of the cave yielded surprisingly old ages that range from 33,448 to 28,279 cal BP, a time prior to the Last Glacial Maximum. Because these early ages are many thousands of years older than current models estimate for the peopling of the Americas, they require reassessments of the artifacts and ecofacts excavated from these early zones.

After decades of study, much remains unknown about the foraging practices of the earliest inhabitants of Puerto Rico. Here, we present an analysis of the malacological assemblages of two neighboring and (partially) contemporary early sites from the island's southwest, finding intriguing intersite differences in shellfish collection practices. We attribute this diversity to differences in site type, chronology, or changes in local coastal configuration. This work not only provides insights into prehistoric Puerto Rican foraging dynamics but also demonstrates the importance of considering factors including intra-age chronology, site type, and changes in paleoenvironmental conditions when considering ancient foraging practices.