En este trabajo se presentan los resultados de estudios experimentales realizados en pastas cerámicas con el objetivo de comprender las elecciones técnicas realizadas por los grupos cazadores-recolectores que habitaron el curso inferior del Río Colorado (transición pampeano-patagónica oriental) en los últimos 2000 años aP aproximadamente. A tal efecto, con la guía de ceramistas locales, se realizaron ensayos tanto en el campo como en el laboratorio, empleando materias primas (arcillas y arenas) obtenidas del área de estudio. Durante las tareas de campo se realizó el testeo inicial y la cocción de las materias primas, actividades que se repitieron en el laboratorio. A esto se agregó una batería de estudios arqueométricos (e.g., petrografías, DRX, FTIR, SEM-EDAX) cuyos resultados fueron comparados con la información arqueológica del área. En este sentido, la composición de las materias primas, las temperaturas y condiciones de quema, así como los patrones tecnológicos de las pastas experimentales, son concordantes con las registradas en las cerámicas arqueológicas. La integración de estos datos indicaría la producción preponderantemente local de las vasijas como también la transmisión de una práctica alfarera a lo largo del Holoceno tardío.

We present the first geochemical data of archaeological obsidian for Isla Victoria, Nahuel Huapi National Park in Patagonia. XRF analyses were performed on 15 samples of obsidian-like rocks from the Puerto Tranquilo 1 site. Only five of the artifacts—all of which come from upper levels of the site—correspond to obsidian as a raw material. The provenance analysis indicates the use of obsidian sources located in the Andean Forest area of southern Neuquen Province. Based on these preliminary results, we propose a north–south circulation axis for this raw material. These geographic results are discussed in relation to the information available regionally.

Beach ridges are depositional features that allow reconstruction of past sea-level variations, sediment dynamics, and storm activity. However, there are still very few systematic studies focusing on beach ridges available from the Gulf of Thailand. Along the east coast, satellite images provide evidence of beach ridges in the Chanthaburi Province, extending as far as 6 km inland, oriented parallel to the current coastline. These can be divided into a set of landward ridges (5.3–6.0 km inland) and seaward ridges (0.4–1.8 km inland) that are separated by an arm of the Chanthaburi estuary. Optically stimulated luminescence dating of 26 sand samples from 12 pits of ridge profiles suggests that the landward set of beach ridges formed ca. 3500 yr ago, while the seaward set of ridges formed between ca. 2100–1200 years ago, which also includes the modern active beach. It appears that the landward set of beach ridges developed during a period of relatively stable sea level followed by a rapid regression presently occupied by the arm of the Chanthaburi estuary. The seaward set of beach ridges apparently reflects a millennium of slowly retreating coastline until the modern beach ridge formed.

Este trabajo de tecnología lítica aborda los cambios acontecidos durante las ocupaciones de las últimas poblaciones cazadoras-recolectoras-domesticadoras, y de las sociedades agropastoriles tempranas en la Puna de Jujuy. En particular, tiene como objetivo reconstituir las cadenas operativas y los sistemas técnicos a partir de tres sitios de la cuenca de Barrancas entre aproximadamente 3750 y 1550 años cal aP. Los resultados comprenden varios análisis cuantitativos —incluyendo riqueza y diversidad— sobre las materias primas, los métodos de desbaste y de façonnage, y las unidades tecno-funcionales prensiles (UTFp). Los resultados demuestran que, a pesar de observarse continuidades, los cambios tecnológicos son significativos e incluyen rupturas. En particular, las evidencias indican una reorganización de los sistemas técnicos y de la gestión de las materias primas. Uno de los aspectos destacables es que el enastilamiento de instrumentos fue más importante durante el Holoceno medio que en el Holoceno tardío. Estos cambios se interpretan en el marco de una reestructuración social, económica y ecológica.

Lakes in the semiarid Southern Interior Plateau of British Columbia, Canada are vulnerable to future climate-driven changes in water quantity and quality. However, few long-term monitoring records exist to assess the effects of varying hydroclimate conditions on lake function. We present a high-resolution multiproxy paleolimnological record containing subfossil diatoms, μXRF via ITRAX, and chlorophyll-a that spans the past 1800 years from Roche Lake in south-central British Columbia. Generalized additive models indicate that the diatom assemblages were associated with changes in lake level and the accompanying effects of atmospheric forcing on lake thermal structure, and that these forcing mechanisms had a weak relationship with primary production. We infer two pronounced arid periods between ca. AD 600–950 and ca. AD 1730–1950 that correspond to evidence of reduced lake mixing and enhanced anoxia, but variable patterns in primary production. Synthesis of regional proxy records suggests that inferences of moist but possibly warm conditions during the Medieval Climate Anomaly may have occurred because of a complex interaction between prolonged La Niña-like conditions and higher radiative forcing. Overall, lakes in this region are sensitive to changes in hydroclimate generated by interactions between external forcing and Pacific Ocean–atmosphere processes, and the resulting changes in aridity may have potentially negative consequences on salmonid habitat.

Detrital sediments of the Sea of Galilee are predominantly pedogenic products of settled dust and local bedrocks transported from Upper Galilee and the Golan Heights. Using the mineralogy, chemistry, and Nd and Sr isotope ratios of the core LK12-22 collected offshore of the Ginosar valley and of contemporaneous soils from the Nahal Tzalmon and Nahal Amud catchments, we reconstructed Late Holocene regional hydroclimate. The core samples span ɛNd isotope values of −6 to −2 and 87Sr/86Sr ratios of 0.7075 to 0.7077 between the isotope fields of the Terra rossa soils and basaltic soils. Sediments from the drier Iron Age and Arabic and Ottoman periods are closer in Nd-Sr isotope ratios of the basaltic soils, while those of the wetter Middle to Late Bronze and Roman–Byzantine periods are closer to the Terra rossa soils, reflecting enhanced mobilization of sediments from the Tzalmon catchment where Terra rossa–type soils accumulated. This result corroborates other regional data that indicate semiarid to temperate conditions in the south Levant during most of the Late Holocene. Wetter conditions over the Galilee Mountains and the Ginosar valley catchment during the Roman period could have promoted the flourishing farming-fishing society that heralded the rise of Christianity.

The 4.2 ka event is widely presumed to be a globally widespread aridity event and has been linked to several episodes of societal changes across the globe. Whether this climate event impacted the cultural development in south-central China remains uncertain due to a lack of regional paleorainfall records. We present here stalagmite stable carbon isotope and trace element–based reconstruction of hydroclimatic conditions from south-central China. Our data reveal a sub–millennial scale (~5.6 to 4.3 ka) drying trend in the region followed by a gradual transition to wetter conditions during the 4.2 ka event (4.3–3.9 ka). Together with the existing archaeological evidence, our data suggest that the drier climate before 4.3 ka may have promoted the Shijiahe culture, while the pluvial conditions during the 4.2 ka event may have adversely affected its settlements in low-lying areas. While military conflicts with the Wangwan III culture may have accelerated the collapse of Shijiahe culture, we suggest that the joint effects of climate and the region's topography also played important causal roles in its demise.

Bubiyan Island, presently a vast sabkha and salt flat in the westernmost part of the Shatt Al-Arab delta, originated ca. 4000 cal yr BP as prodelta deposits from a paleochannel of the Euphrates River that flowed into a shallow sea. Southeastern Bubiyan Island first surfaced when spits and barrier islands formed on a 1–2 m forebulge caused by heavy sediment load to the northwest; the spits and barriers delineated an incipient shoreline and sheltered a shallow lagoon. Progradation of southeastern Bubiyan Island began when the spits and barriers were gradually stranded as beach ridges during minor sea-level fluctuations and continued marginal uplift. AMS dating of the beach ridges, which are ~1–5 km from the present shoreline, implies that Late Holocene relative sea level fell in three phases: ca. 3700–3400 cal yr BP, ca. 2600–1000 cal yr BP, and ca. 600–500 cal yr BP. Prior to each phase, relative sea level apparently stabilized to near stillstands, allowing spits and barriers to accrete. Torpedo-jar pottery sherds scattered on some of the most prominent beach ridges indicate Sasanian (AD ca. 300–650; 1650–1300 cal yr BP) to early Islamic (AD ca. 650–800; 1300–1150 cal yr BP) periods of human presence, concurrent with the Second phase of beach-ridge formation.

Little is known about the dynamics of marine food chains spanning primary to higher trophic levels on centennial and longer timescales, especially where the supply of dissolved iron limits primary productivity. To elucidate the long-term dynamics of biological productivity in the Coastal Oyashio (CO), which is a major pathway for transporting dissolved iron into the western North Pacific from winter to spring, we reconstructed the lower trophic level productivity over the last 3000 years in the CO. Our results demonstrate that the concentrations and mass accumulation rates of both Chl-a (chlorophyll a and its derivatives) and biogenic opal used as proxies of primary productivity, and steryl chlorin esters (SCEs) used as that of zooplankton productivity, show a millennial-scale increasing trend and centennial-scale variability beginning ca. AD 400. SCEs were positively correlated with Chl-a, indicating that changes in zooplankton productivity were induced by bottom-up control of primary productivity. The Chl-a and SCEs showed synchronous centennial-scale patterns with a relative abundance of sea-ice-associated diatom species transported by CO, and with a ventilation index in the Okhotsk Sea Intermediate Water. This synchronous pattern indicates that lower trophic-level productivity during the spring bloom responded to the intensity of iron-replete CO.

Caracterizar las estrategias de movilidad de las sociedades cazadoras-recolectoras-pescadoras en ambientes insulares y litorales es fundamental para comprender la interacción humano-ambiental en el pasado. Las prospecciones en el noreste de la isla Diego Portales, en el mar interior de Última Esperanza (Magallanes, Chile), han permitido documentar ocho yacimientos arqueológicos formados por uno o varios conchales. Todos ellos se hallan ubicados en áreas de la costa al resguardo del viento dominante y con fácil acceso mediante embarcación. Los trabajos arqueológicos en dos de estos yacimientos (Bahía Easter 1 y 2) indican una estrategia de subsistencia similar durante el Holoceno tardío final, basada en el aprovechamiento de la biodiversidad de este ambiente de ecotono, con más de una docena de recursos marinos y terrestres consumidos. Entre éstas destaca en abundancia el huemul (Hippocamelus bisulcus), probablemente cazado en el litoral continental. Teniendo en cuenta las dinámicas de poblamiento y movilidad propuestas desde la etnografía o la arqueología para otras áreas del archipiélago fuego-patagónico, los resultados permiten discutir la reocupación sucesiva de puntos estratégicos de la isla, particularmente en primavera-verano, cuando la encrucijada de caminos y recursos que representa el mar interior de Última Esperanza presentaba alicientes significativos para las comunidades canoeras.

Climate changes over the past two millennia in the central part of the Gulf of St. Lawrence are documented in this paper with the aim of determining and understanding the natural climate variability and the impact of anthropogenic forcing at a regional scale. The palynological content (dinocysts, pollen, and spores) of the composite marine sediment core MSM46-03 collected in the Laurentian Channel was used to reconstruct oceanographic and climatic changes with a multidecadal temporal resolution. Sea-surface conditions, including summer salinity and temperature, sea-ice cover, and primary productivity, were reconstructed from dinocyst assemblages. Results revealed a remarkable cooling trend of about 4°C after 1230 cal yr BP (720 CE) and a culmination with a cold pulse dated to 170–40 cal yr BP (1780–1910 CE), which likely corresponds to the regional signal of the Little Ice Age. This cold interval was followed by a rapid warming of about 3°C. In the pollen assemblages, the decrease of Pinus abundance over the past 1700 yr suggests changes in wind regimes, likely resulting from increased southerly incursions of cold and dry Arctic air masses into southeastern Canada.

The first millennium AD encompasses the Roman period (12 BC to AD 450) and the Early Middle Ages (AD 450 to 1050). In the Netherlands, this millennium saw population growth, steep decline and subsequent revival. In addition, many changes occurred in the physical landscape, marking a transition from a mainly natural prehistorical lowland landscape to an increasingly human-affected landscape. This paper synthesises the main landscape changes and human–landscape interactions in the Netherlands during this dynamic period. The degree of landscape change is compared between the coastal plain, the delta and the Pleistocene sand area.

Human activities caused major often unintended geomorphological changes in all studied landscapes. Landscape sensitivity to human impact, however, strongly varied as a function of preceding landscape state. The most prominent changes took place in many parts of the coastal plain, where back-barrier peatlands transformed into open tidal basins. Presence of compaction-prone peat and intensified artificial drainage led to subsidence. This precondition and slow anthropogenic forcing combined, made the area more sensitive to stochastically occurring storms, which could serve as tipping points for large-scale drowning. Eventually, major peatlands turned into tidal areas that for many centuries would remain unsuitable for habitation. Human-induced peatland subsidence also led to the formation of the new Hollandse IJssel and Lek river branches. This marked a major reorganisation of the river network in the lower Rhine–Meuse delta. In the middle and upstream parts of the delta, the landscape was more stable. Yet, settlements on the natural levees show adaption to increasing flooding frequency from the Late Roman period onwards. The settlements shifted towards higher positions, while route networks between them largely remained intact. Smaller-scale landscape changes were found in the Pleistocene sand area. Here, local sand drifting occurred, most frequently occurring close to human movement corridors. Drift sand intensity became larger as population density increased after c.AD 900.

Tree-rings representing annual dates from live and deadwood Pinus flexilis at ten sites across the central Great Basin (~38°N) yielded a cumulative record across 4002 years (1983 BC–AD 2019). Individual site chronologies ranged in length from 861–4002 years; all were continuous over their sample depths. Correlations of growth with climate were positive for water relations and mostly negative for summer temperatures. Growth was generally correlated across sites, with the central Nevada stands most distinct. Although growth was low during the Late Holocene Dry Period, variability marked this interval, suggesting that it was not pervasively dry. All sites had low growth during the first half of the Medieval Climate Anomaly, high growth during the mid-interval pluvial, and low growth subsequently. Little synchrony occurred across sites for the early Little Ice Age. After AD 1650, growth was depressed until the early twentieth century. Growth at all sites declined markedly ca. AD 1985, was similar to the lowest growth period of the full records, and indicative of recent severe droughts. A small rebound in growth occurred after ca. AD 2010. A strong signal for Atlantic Multidecadal Oscillation (AMO) occurred in growth response at most sites. The persistence of all stands despite climate variability indicates high resilience of this species.

Mormon Lake, elevation 2166 m with maximum historic surface area of 31.4 km2, lies in a forested endorheic basin covering 103 km2. It is the largest unaltered freshwater body on the 337,000 km2 Colorado Plateau. Prehistorical (before AD 1878) highstands were ca. 9 and 24 m relative to depocenter datum. These levels likely occurred during four multidecadal episodes of cool, wet conditions between ca. 3.55 and 0.20 ka BP. Maximum historical levels (early 1900s) were up to 7.9 m, whereas modern (post-1941) levels were frequently zero or relatively low. Historical climate records indicate reconstructed lake levels correlate directly with annual precipitation and inversely with temperature. Early highstands were associated with above average precipitation and the lowest temperatures of the 116 yr record. The lake receded after 1941; thereafter, frequent drying and low-water levels resulted from recurrent drought and steadily increasing temperatures. Consequently, a wet episode from the 1970s to the 1990s had precipitation like the early 1900s, but highstands were only ca. 3.8 m. The historical lake-level chronology is consistent with changes of hydrologic balance predicted by climate models, that is, reduced effective precipitation (precipitation minus evaporation). These changes, particularly aridification, apparently began in the 1970s or earlier. Global oceanic and atmospheric climate modulate lake levels and regional hydroclimate.

We explore marine reservoir effects (MREs) in seal bones from the northern Bering and Chukchi Seas regions. Ringed and bearded seals have served as dietary staples in human populations along the coasts of Arctic northeast Asia and North America for several millennia. Radiocarbon (14C) dates on seal bones and terrestrial materials (caribou, plants seeds, wood, and wood charcoal) were compared from archaeological sites in the Bering Strait region of northwestern Alaska to assess MREs in these sea mammals over time. We also compared these results to 14C dates on modern seal specimens collected in AD 1932 and 1946 from the Bering Sea region. Our paired archaeological samples were recovered from late Holocene archaeological features, including floors from dwellings and cache pits, that date between 1600 and 130 cal BP. 14C dates on seal bones from the northern Bering and Chukchi Seas show differences [R(t)] of 800 ± 140 years from to their terrestrial counterparts, and deviations of 404 ± 112 years (ΔR) from the marine calibration curve.

Este trabajo contribuye, desde la bioarqueología, al estudio de la dieta de las poblaciones que habitaron el sur del Noreste argentino (NEA) durante el Holoceno tardío (desde ca. 2000 aP). Específicamente, se evalúa el consumo de vegetales y los posibles modos de procesamiento de los alimentos. Se revelan diferentes bioindicadores bucodentales en tres muestras bioarqueológicas de tres sectores geográficos: Delta superior e inferior del río Paraná (entre ca. 570 y 850 cal aP) y cuenca inferior del río Uruguay (ca. 2000 cal aP). Los bioindicadores observados en las tres muestras (1.355 dientes y 1.693 alveolos) se ajustan a lo esperado para economías mixtas de caza-pesca-recolección y horticultura. Los recursos animales constituyeron el componente principal de la alimentación, mientras que el consumo de vegetales fue un importante complemento en la dieta. Se registran diferentes modos de procesar los alimentos que atenuaron el estrés masticatorio y se destaca que la dieta habría sido más abrasiva en la muestra del Uruguay inferior en comparación con las otras dos muestras. Los resultados obtenidos, al integrarse con información disponible de otras líneas de análisis (e.g., arqueobotánicas, zooarqueológicas), aportan y amplían el conocimiento sobre la alimentación de las poblaciones prehispánicas del sur del NEA.

El registro de Canis familiaris en contextos arqueológicos resulta cada vez más frecuente en Sudamérica. En este escenario, este trabajo discute su rol económico y social dentro de las sociedades indígenas prehispánicas. Se presentan nuevos hallazgos de perros procedentes de cinco sitios arqueológicos del Noreste argentino. La muestra estudiada incluye siete especímenes craneales y uno poscraneal correspondientes a individuos jóvenes y adultos, de tamaños medianos (13-23 kg). Algunos de los especímenes presentan huellas de corte y marcas de carnívoros. Tres nuevas fechas taxón ubican a la muestra entre aproximadamente 2500 y 900 cal aP. Se concluye que C. familiaris presenta edades y tamaños ligeramente mayores a los registrados previamente. Asimismo, la evidencia antrópica indica procesamiento y consumo de esta especie. Las dataciones extienden el rango cronológico conocido previamente para este taxón en Argentina, Brasil y Uruguay. Su presencia se vincula a cazadores-recolectores-pescadores y horticultores, con una marcada adaptación fluvial durante el Holoceno tardío.

We explored the site context of a late Holocene shell midden on the coast of Los Vilos in north-central Chile (31°51′ S, South America) to better understand the spatial organization of short-term, small-sized hunter-gatherer campsites. The Dunas de Agua Amarilla (LV 007) site comprises 14 separate surf clam refuse deposits. Extensive stratigraphic excavations of the shell middens and the areas free of residue allowed interpretation of potential activity areas bounded by hearths, the shell middens, and a possible dwelling space. Late Holocene campsites in the area correspond to brief occupational events framed within littoral residential mobility, in which predictable coastal resources became a staple for groups residing and circulating over long periods in the area. Data on shell midden composition and the spatial distribution of site features shed light on the organizational dynamics of dwelling and activity spaces of coastal hunter-gatherers of the South Pacific.

En este trabajo se discute la movilidad y uso del espacio terrestre por parte de los grupos cazadores-recolectores costeros que habitaron la Bahía Moat, en la costa sureste de Tierra del Fuego, Argentina. Para ello, se analizan las pautas de explotación del guanaco (Lama guanicoe), único animal terrestre que tuvo un rol significativo para la subsistencia y requirió planificación en términos logísticos para su aprovechamiento. Los conjuntos estudiados corresponden al Holoceno tardío y los restos óseos se analizan en función de distintos modelos y marcos de referencia que evalúan las modalidades de búsqueda, transporte y procesamiento de camélidos. Los resultados alcanzados permiten plantear que la organización espacial de las prácticas de subsistencia pudo haberse desarrollado a partir de un alto dinamismo entre la costa y el interior. El elevado consumo de guanacos, junto con los patrones de selección y transporte, sugiere que las partidas de caza hacia el interior y las zonas ecológicas adyacentes al litoral pudieron haber estado integradas logísticamente dentro de un sistema de movilidad residencial localizado geográficamente en la costa.