The Moche civilization of the north coast of Peru is thought to be the first state-level society in South America. Understanding of the emergence, spread, and decline of this society, however, has been based almost entirely on relative ceramic phases, rather than absolute dates. This article reevaluates Moche political dynamics and intersite affiliations using radiocarbon dates associated with diagnostic ceramic styles. The phases of ceramic styles at individual sites are estimated using Bayesian models of published 14C dates that have passed explicit selection criteria for reliability. The site-specific phases are incorporated into a regional chronology, which adds additional support to the idea that Moche was a collection of independent polities with complex and nuanced relationships. Based on absolute dates, Moche civilization appears to have spanned between cal AD 200–900, with a significant and socially meaningful increase in stylistic homogeneity between cal AD 600–650.

A fundamental aspect of ancient Egyptian history remains unresolved: chronology. Egyptologists (and researchers in related fields that synchronize their studies with Egypt) currently rely on a variety of insufficiently precise methodologies (king lists, radiocarbon dating, etc.) from which to derive seemingly “absolute” dates. The need for genuine precision has been recognized for a century, as has the potential solution: dendrochronology. This manuscript presents a case for further progress toward the construction of a tree-ring chronology for ancient Egypt.

This article focuses on constructing a high-resolution age-depth model for the Puścizna Mała peat bog located in Orawa-Nowy Targ Basin (S Poland). The chronology was established on the basis of both 210Pb and 14C measurements, and further confirmed by pollen diagrams and the peat bulk composition (density, ash content, and measurements of C, N, S). The 137Cs profile revealed significant downward migration of this radionuclide and was not suitable for geochronological interpretation. The peat profile in southern Poland records almost 2000 yr of paleoecological and geochemical changes. Major historical events linked to anthropogenic and climatic changes are recorded in the investigated proxies, which confirm the reliability of the age-depth model. Specifically, the Roman period, Migration period, Medieval times, as well as the Industrial Revolution are reflected in the palynology and bulk composition of the peat. However, dating results obtained for the core segment between 22–45 cm are problematic when confronted with other analyses. The highest peat accumulation rate of 2 mm yr-1 (AD 1300–1400 according to the age-depth model) is not compatible with the section of the highest peat decomposition revealed by lithological description. Moreover, the onset of a drastic decline of forests reflected in the palynological data and dated to AD 1280–1340 (40 cm) is difficult to explain in the light of historical data. Therefore, the lithology, bulk density, and pollen were used to validate the obtained age-depth model. External forcing factors on the peat formation process may be indicated, including agricultural activity, water-level fluctuations, and natural climatic factors, which paradoxically caused doubling of the obtained peat accumulation rate.

A summary is presented of more than a decade-long study of direct radiocarbon dating for one of the most important human burials in Eurasia, the Sungir site in eastern Europe. Eighteen 14C dates were produced before early 2014 on three skeletons (Sungir 1–3), and there is still no consistency in the results. In the absence of other independent methods to establish the antiquity of Sungir, a careful analysis is performed of the site's stratigraphy, paleoenvironment, and 14C dates run on animal bones from the same layer as the burials. Although the conclusions of this work cannot be guaranteed to be absolutely correct, we suggest that at the present stage of research the age range of ∼26,000–27,210 BP is the most probable time for the creation of the elaborate human burials at the Sungir site.

We assess the state of and potential for expansion of dendroarchaeological research in Egypt. We also report previously unpublished findings, which we hope will assist with the new effort in constructing tree-ring chronologies in Egypt. In doing so, we explain briefly some of the problems and potential of the future enterprise.

Characterized by a dry climate, the arid area of China represents a unique landscape. A proper understanding of the driving mechanisms behind the changes of this ecologically vulnerable landscape requires placing the instrumental records within a geological context. Lakes in this area bear rich information about past climatic and environmental changes presumably regulated by the westerlies at various timescales. The lacustrine records obtained in this area heavily rely on radiocarbon ages, which are usually subject to the temporal and spatial variability of the 14C reservoir effect. Yet, little is known about the 14C reservoir age of lacustrine systems in this area. This study reports an anomalously large 14C reservoir age of about 11,000 ± 2000 yr from a saline lake in NW China by comparing 14C and OSL chronologies. The modeling study suggests that this age offset appears to be an inherent phenomenon in lacustrine systems, which mainly arises from the introduction of pre-aged organic matter from the catchment and the conversion of 14C-depleted dissolved inorganic carbon to organic matter by photosynthesis. Compared to the large age offset induced by the 14C-dcficient exogenous carbon, the reservoir effect due to retention of organic matter in the lake water appears to be inconsequential. The results reveal the pitfall of 14C dating on organic-poor bulk lacustrine sediments in this barren landscape, and thus highlight the need for alternate dating methods to constrain the chronology of lacustrine records.

Archaeologists tend to use typochronological frameworks to date their sites. These are based on the appearance of certain cultural markers such as grave types or houseplans. In the Meuse-Demer-Scheldt region, a chronological framework is used for the cremation cemeteries from the Middle Bronze Age until the Late Iron Age based on the size, number, and presence of different types of cremation graves. Radiocarbon dating of cremated bone from the small cemetery at Lummen-Meldert dates this site to the Late Bronze Age. These results challenge the hypothesis that small cremation cemeteries with mostly “unurned” graves date to the Middle Iron Age. The cremation graves without an urn and grave goods are a specific category that has to be dated by absolute dating methods such as 14C. The results also suggest a connection with the funerary traditions in the Atlantic region.

Archaeologists working in the Belize Valley have argued for the persistence of Maya populations from the Classic (AD 300–900) through Postclassic (AD 900–1500) periods since Gordon Willey's groundbreaking settlement survey and excavation work in the 1950s. This is contrary to the trajectory recorded in some parts of the Maya region where there is clear evidence for political disruption and population decline at the end of the Classic period. The argument for continuous Classic to Postclassic occupation in the Belize Valley remains ambiguous due to researchers' reliance on relative ceramic chronologies. This article reports the results of direct accelerator mass spectrometry (AMS) radiocarbon dating of human skeletons (n = 12) from the important center of Baking Pot, Belize, which is thought to provide some of the best ceramic evidence for continuity in the valley. The AMS dates show a long span of mortuary activity between the Middle Preclassic and Late Classic periods (405 cal BC to cal AD 770), with a hiatus in activity during the Early Postclassic (cal AD 900–1200) and subsequent activity in the Late Postclassic (cal AD 1280–1420). These results are not consistent with the idea that Baking Pot was occupied continuously from the Classic through Postclassic periods. This work highlights the need for additional AMS 14C work at Baking Pot and elsewhere to establish absolute chronologies for evaluating the political and demographic collapse of Classic Maya regional centers.

This article proposes a new four-phase chronology for Postclassic and colonial occupation at Xaltocan, Mexico, using Bayesian statistical modeling of a suite of 54 radiometric dates. Of these, 46 samples come from recent extensive excavations of sealed, stratified household deposits, facilitating improved understanding of sample context and resulting in a more accurate chronology. The timing of the adoption of major ceramic wares at the site and intrasite level is outlined and contextualized within broad, regional phases. These results are particularly valuable given recent research that repudiates a uniform chronological framework for the Basin of Mexico in the Postclassic period, and indicates instead a significant amount of chronological overlap and regional variation in the use of distinct ceramic types.

Radiocarbon accelerator mass spectrometry (AMS) techniques were used to date total organic carbon and plant seeds in the lFs core sequence (36°48′N, 100°08′E) from Qinghai Lake, China. This core was drilled ∼18 m into Qinghai Lake sediments as part of an international cooperative research project, “Scientific Drilling at Qinghai Lake in the Northeastern Tibetan Plateau: High-Resolution Paleoenvironmental Records of Eastern Asia Linked to Global Change,” which began in 2004. Based on the differences in lithology and total organic content (TOC) in core lFs, the core was divided into 3 sections for age-modeling purposes: the upper ∼499 cm lacustrine silty clay to clay; the middle unit of silty clay with silt layers from 499–901 cm; and the lower 901–1861 cm silty clay, loess-like silt, and fine sand layers. Three different approaches are applied to the reservoir age problem. First, a simple linear regression gives an offset of 1342 yr. If the core is divided into three sections, linear regressions can be applied separately for the three segments, which results in an age estimate for the average hardwater effect of ∼135 yr BP for the surface section up to 499 cm. If extrapolated for deeper sections, these results imply a higher reservoir offset for those two sections, which may be as much as 1143 and 2523 yr, but this assumes that there are no discontinuities in the core. A third approach using a wiggle-matching approach gave an offset of 196 yr. This study concludes that the reservoir age of Qinghai Lake is complex, but these new data add to our understanding of the 14C chronology of Qinghai Lake for the last 32 ka.

Since Marcel Edouard Mariën and his 1952 masterpiece synthesis Oud-België van de eerste landbouwers tot de komst van Caesar, the beginning of the Late Bronze Age in Belgium has been situated around 1100 BC, corresponding to the phase Ha A2. The scarcity of artifacts from Reinecke's phases Bz C and Ha Al seemed to confirm this theory. Based on an axe's hoard (Maaseik, Belgium) and the presence of grooved ware, the potential existence of a Bz D/Ha Al phase has been suggested but certainly not certified. Currently, a large campaign of analyses on bones from several Late Bronze Age sites is shedding new light on Bronze Age chronology.

This study argues that to properly set the duration of a particular pottery style using radiocarbon it is necessary to have a long series of data, but also to critically evaluate its reliability. This study presents a methodological strategy to establish the temporal position of the Famabalasto Negro Grabado (Famabalasto Black Incised) pottery style, which has a problematic chronological allocation in northwest Argentine archaeology. This article considers as a starting point the different hypotheses referring to the chronology of this ceramic style. All available 14C dates and the information of the archaeological contexts were used to evaluate the different degrees of certainty in the sample-event association and differentiate the association degrees among the dated events and the set of recovered ceramics. For this, a quadripartite scale of date-pottery association is proposed. This treatment of the information allows to rank the more reliable data. Anomalous data are detected and discussed, and as a result, the period of production of this style at a regional level can be dated to the early 14th century and mid-16th/carly 17th century. This analysis presents a methodology that can be applied to different archaeological situations.

To formulate a solid chronology of the northwest Belgian Bronze Age barrow phenomenon, a critical review of the available radiocarbon dates was necessary. The resulting 14C chronology of the barrows was compared with the 14C chronologies of the Late Neolithic Bell Beaker graves, the Bronze Age metalwork depositions, the evidence of barrow reuse, and the Bronze Age longhouses. This research revealed interesting patterns concerning the appearance and disappearance of the barrow phenomenon. The earliest 14C-dated barrows are dated during the Late Neolithic and coincide with the presence of the Bell Beaker culture in the region. The peak of the barrow-building practice occurred between 1700 and 1500/1400 cal BC, a period of flourishing trade networks in the regions along the North Sea basin. The period around 1500 cal BC is characterized by the disappearance of barrow-building practices and the sudden appearance of ritual depositional practices, reflecting changes in society.

The chronology of the Neolithic and Bronze Age cultures in Gansu and Qinghai provinces, northwest China, is mainly based on conventional radiocarbon dates from unidentified charcoal, which may be inaccurate in view of the possible “old wood” problem of 14C dating. To discuss the reliability of the chronology of those prehistoric cultures, accelerator mass spectrometry (AMS) dates of short-lived charred seeds were compared to conventional 14C dates of unidentified charcoal from the same flotation samples in 15 Late Neolithic and Bronze Age sites in the area. The results show that 14C dates of unidentified charcoal are obviously older than those of charred seeds in 5 of the 15 flotation samples. This work suggests that the old-wood problem of 14C dating might be related to human subsistence strategies and local vegetation variation during different prehistoric cultural periods in Gansu and Qinghai provinces, which should be discussed before establishing the chronology of Neolithic and Bronze Age cultures in the area.

Since the beginning of the Holocene, hunter-gatherers have occupied the central-south Brazilian coast, as it was a very productive estuarine environment. Living as fishers and mollusk gatherers, they built prehistoric shellmounds, known as sambaqui, up to 30 m high, which can still be found today from the Espírito Santo (21°S) to Rio Grande do Sul (32°S) states, constituting an important testimony of paleodiversity and Brazilian prehistory. The chronology of the Sambaqui da Tarioba, situated in Rio das Ostras, Rio de Janeiro, is discussed herein. Selected well-preserved shells of Iphigenia brasiliana and charcoal from fireplaces in sequential layers were used for radiocarbon dating analysis. Based on a statistical model developed using OxCal software, the results indicate that the settlement occupation begun most probably around 3800 cal BP and lasted for up to 5 centuries.

A review of recently published temporal data from Shuidonggou Locality 1 indicates that a 40–43 cal ka date for the inception of Initial Upper Paleolithic (IUP) blade-oriented technologies in East Asia is warranted. Comparison of the dates from Shuidonggou to other Asian IUP dates in Korea, Siberia, and Mongolia supports this assertion, indicating that the initial appearance of the IUP in East Asia generally corresponds in time to the fluorescence of the IUP in eastern Europe and western Asia. This conclusion preliminarily suggests that either a version of the IUP originated independently in East Asia just prior to 40 cal ka, or more likely, that an early, initial diffusion of the IUP into East Asia occurred ∼41 cal ka, a hypothesis consistent with current estimates for the evolution or arrival of modern humans in the region.

Atmospheric CO2 and aquatic water samples were analyzed to evaluate the environmental 14C enrichment due to operation of the Qinshan nuclear power plant (NPP), where two heavy-water reactors and five pressurized-water reactors are employed. Elevated 14C-specific activities (2–26.7 Bq/kg C) were observed in the short-term air samples collected within a 5-km radius, while samples over 5 km were close to background levels. The 14C-specific activities of dissolved inorganic carbon (DIC) in the surface seawater samples ranged from 196.8 to 206.5 Bq/kg C (average 203.4 Bq/kg C), which are close to the background value. No elevated 14C level in surface seawater was found after 20 years of operation of Qinshan NPP, indicating that the 14C discharged was well diffused. The results of the freshwater samples show that excess 14C-specific activity (average 17.1 Bq/kg C) was found in surface water and well water samples, while no obvious 14C increase was found in drinking water (groundwater and tap water) compared to the background level.

The archaeological site of Tlatoani at Tlayacapan is located in the Mexican Highlands, in the present-day state of Morelos. The site is an extant settlement located at the top of the Tepoztlan mountain range, and has been occupied since the Late Preclassic period (AD 150–500). At the height of its occupation in the Epiclassic and Early Postclassic periods (AD 600–1150), Tlayacapan was situated on the top of the hill. The radiocarbon investigations reported herein revealed some further distinct findings, although no clear absolute chronology was demonstrated. A dog skull was found inside the oldest foundation stage, and dated between cal AD 646 and 765, the middle of the Epiclassic period. Human remains found in the first grave belonged to three individuals. A male skeleton was dated to AD 1158–1227. Fragments of an incomplete skeleton of a child and an incomplete skeleton of a second male were placed on top of the first male skeleton and were dated in the range AD 1030–1156. A fourth skeleton found nearby in the second grave gave a similar date of AD 1164–1253. These burials were in accordance with the Middle America cosmovisional system, where bodies were buried beneath the household space. It is evident from the 14C dates of the skeletons that the burial sites beneath the household space had been reused by exhuming and reburying skeletons that had been previously buried there. A comparison of dates on fractions of collagen and bioapatite of the same bones was possible. Two of the samples were in good agreement between these fractions, whereas the other three samples are close but just outside the 2σ range.