Shahack-Gross and Finkelstein (2015) further developed their theory, based on microarchaeology, that there was no agriculture in the Negev Highlands during the Iron Age. We critically evaluate their article in this rejoinder and propose that their conclusion is an example of overinterpretation from a small amount of indirect data. Based on phytoliths in two courtyards and a few rooms, i.e. structures not related to farming, they construed the absence of agriculture during the Iron Age in an area of 2000 km2. We present new radiocarbon, macroarchaeological, and microarchaeological data of Horvat Haluqim, showing that agriculture in the Negev Highlands based on runoff/floodwater capture and related terrace wall construction did not begin with the Roman–Byzantine period. Terrace agriculture in the Negev is older and includes also the Iron Age.

This article presents new values for the Scottish marine radiocarbon reservoir effect (MRE) during the Mesolithic at 4540–4240 BC (6490–6190 BP) and the Medieval period at AD 1460–1630 (490–320 BP). The results give a ΔR of –126±39 14C yr for the Mesolithic and of –130±36 14C yr for the Medieval. We recalculate previously published MRE values for the earlier Holocene in this region, at 6480–6290 BC (8430–8180 BP). Here, MRE values are slightly elevated, with a ΔR of 64±41 14C yr, possibly relating to the 8.2ka BP cold event. New values for the Mesolithic and Medieval indicate lower MRE values, broadly consistent with an existing data set of 37 mid- to late Holocene assessments for Scottish waters, indicating stable ocean conditions. We compare the intercept and probability density function (PDF) methods for assessing ΔR. The ΔR values are indistinguishable, but confidence intervals are slightly larger with the PDF method. We therefore apply this more conservative method to calculate ΔR. The MRE values presented fill important gaps in understanding Scottish marine 14C dynamics, providing confidence when calibrating material from critical periods in Scotland’s prehistory, particularly the Mesolithic, when the use of marine resources by coastal populations was high.

The tuning of plateaus in glacial and deglacial planktic radiocarbon records to pertinent structures in the atmospheric 14C record of Lake Suigetsu results in both a record of surface water reservoir ages and a centennial-scale absolute age model. However, the atmospheric origin of planktic 14C plateaus may be questioned. Alternatively, plateaus may result from short pulses of increased hemipelagic sediment deposition, which challenges the technique of 14C plateau tuning. To test the two rationales for the interval 23–12 cal ka, we calculated hypothetical sedimentation rates for all 14C plateaus identified in five Atlantic sediment cores assuming sediment pulses that either span 10, 100, 200, or 300 yr each. These rates were compared to rates derived by 14C plateau tuning that assumes an atmospheric origin of the plateaus. In each plateau suite, our hypothetical sedimentation rates result in at least one or two cases in extreme values that exceed the rates reported for short-lasting pulses of sediment deposition in contourites by a factor of 50 and therefore appear unrealistic. Moreover, they result in entire suites of plateau structures that incidentally appear closely aligned to the pattern of atmospheric 14C plateau suites rather than to any pulses of climate-controlled sediment discharge.

This article presents the results of interdisciplinary analysis of samples from the Czarnówko archaeological site in northern Poland, reporting the first radiocarbon dates for the site in comparison with its relative chronology. The site is of high importance because of its scale and opulence of artifacts. It was used for over 900 yr, from the 7th century BC up to the 3rd century AD, by populations of different cultures (the Lusatian, Pomeranian, Oksywie, and Wielbark). Samples of charcoal, wood, and textile were collected from different features, most of them from burials. Charcoal was taken from cremation pits, while wood was sampled from coffins in skeletal burials. Among samples collected during archaeological excavations in 2008 and 2010, 20 were chosen for 14C dating and macro- and microscopic observations. Images taken using a scanning electron microscope revealed the microstructure and preservation level of the specimens. An emphasis was also placed on geomorphological and geological research of the site area to gain information about the environmental conditions influencing the samples’ preservation state, e.g. pH, type, origin and permeability of sediment, and accumulation of organic matter. The obtained calibrated 14C ages are in agreement with the relative chronology based on the typology of artifacts and stratigraphic site reconstructions.

This article presents the results of direct accelerator mass spectrometry (AMS) radiocarbon dating of a new bone anvil retrieved in the Iron Age–Roman site of Montefí (Ciutadella), in the southwest of the island of Menorca (western Mediterranean). The radiometric date confirms the chronology obtained through the stratigraphy and typological analysis of ceramics (1st–3rd century AD), and indicates that this bone-made tool not only represents the first archaeological anvil from the island but also constitutes the earliest evidence in the western Mediterranean. This ancient date is more consistent with the known eastern regional chronology and reinforces the importance of obtaining direct AMS 14C dates to refine artifact chronologies.

The Late Quaternary climate in Amazonia is an issue still open to debate, with hypotheses varying from alternate dry and wet episodes to stable climate with undisturbed rainforest. We approach this question using δ13C, C/N, and, to a lesser extent, δ15N from deposits derived from four cores, with the results combined with published pollen data from two of these cores. These data were analyzed within the context of radiocarbon dating, which revealed ages ranging from 42.8–41.8 to 2.3–2.2 cal ka BP. Fluvial channel and floodplain deposits with freshwater phytoplankton recorded a trend of wet climate with dry episodes before ~40 cal ka BP, followed by humid and cold climate until the Last Glacial Maximum, with intensified aridity towards the end of the Late Pleistocene. Peaks of increased contributions in C4 land plants in the mid- to late Holocene were not synchronous and have no correspondence with Amazonian Holocene dry episodes, being due to sedimentary processes related to fluvial dynamics during the establishment of herbaceous fields on abandoned depositional sites. Thus, the climate remained wet in the Holocene, which would have favored the expansion of the Amazonian rainforest as we see today.

This article addresses chronological problems about archaeological sites traditionally associated with the Belén culture from Hualfín Valley (Catamarca, Argentina), analyzing background research, radiocarbon dates obtained by A Rex González before 1970, and 14C dates made since 1996. First, we critically review the chronological sequence built by González for Belén sites, which include the Late period (AD 1100–1480) and Inca period (AD 1480–1536), subdivided into three phases. Methodological problems that could affect results of the first 14C dates are discussed. Based on this review, we present new 14C dating considering extraction contexts, types of samples, calibration curve data used, the laboratory where each date was obtained, and their methods of measuring, characteristics of sites of origin, and associated archaeological material. Finally, using calibrated ranges and Bayesian models, we suggest groups of events that would correspond to different times in the history of late occupations in the valley.

In recent decades, the radiocarbon method has frequently been used for dating organic admixtures in pottery. This method is useful for dating the Late Stone Age cultures in eastern Europe due to the poor availability of other organic materials. On the contrary, Bronze Age sites offer a great variety of organic sources, including remains of wooden structures, charcoal, and human and animal bones. This paper analyzes the 14C dates obtained on bones and pottery from six Bronze Age sites in order to determine the feasibility of 14C pottery dating for this particular period. Bronze Age pottery is made of silty clay containing organic matter, which can comprise older material. Therefore, 14С dates obtained on bones, wood, or charcoal are more representative. This paper analyzes the 14C dates obtained on bones and pottery from six Bronze Age sites. Based on this limited study, the authors conclude that dating of pottery from the Bronze Age is controversial and can result in much older dates. We argue this method is acceptable only if no other organic materials are available.

The chronology of the Inca Empire has traditionally relied on ethnohistoric dates, which suggest that a northern expansion into modern Ecuador began in AD 1463 and a southern expansion into modern Argentina began in AD 1471. We test the validity of these dates with two Bayesian models, which show that the ethnohistoric dates are incorrect and that the southern expansion began before the northern one. The first model of seven dates shows that the site of Chamical, Ecuador, was first occupied cal AD 1410–1480 (95% probability) and has a high probability of being built prior to the ethnohistoric date. The second is an outlier model of 26 14C dates and 19 thermoluminescence (TL) dates from 10 sites along the empire’s southeastern limit in northwestern Mendoza, Argentina. Here, the Inca occupation began cal AD 1350–1440 (95% probability), also earlier than the ethnohistoric date. The model also suggests that the Inca occupation of Mendoza lasted 70–230 yr (95% probability), longer than previously thought, which calls for new perspectives on the timing and nature of Inca conquests and relationships with local groups. Based on these results, we argue it is time to abandon the traditional chronology in favor of Inca chronologies based on Bayesian models.

Fruit carbonate of Buglossoides arvensis (syn. Lithospermum arvense) is a valuable dating and paleoenvironmental proxy for late Quaternary deposits and cultural layers because CaCO3 in fruit is assumed to be accumulated from photosynthetic carbon (C). However, considering the uptake of HCO3– by roots from soil solution, the estimated age could be too old depending on the source of HCO3– allocated in fruit carbonate. Until now, no studies have assessed the contributions of photosynthetic and soil C to the fruit carbonate. To evaluate this, the allocation of photo-assimilated carbon and root uptake of HCO3– was examined by radiocarbon (14C) labeling and tracing. B. arvensis was grown in carbonate-free and carbonate-containing soils (sand and loess, respectively), where 14C was provided as (1) 14CO2 in the atmosphere (5 times shoot pulse labeling), or (2) Na214CO3 in soil solution (root-labeling; 5 times by injecting labeled solution into the soil) during one month of fruit development. Distinctly different patterns of 14C distribution in plant organs after root- and shoot labeling showed the ability of B. arvensis to take up HCO3– from soil solution. The highest 14C activity from root labeling was recovered in roots, followed by shoots, fruit organics, and fruit carbonate. In contrast, 14C activity after shoot labeling was the highest in shoots, followed by fruit organics, roots and fruit carbonate. Total photo-assimilated C incorporated via shoot labeling in loess-grown plants was 1.51 mg lower than in sand, reflecting the presence of dissolved carbonate (i.e. CaCO3) in loess. Loess carbonate dissolution and root-respired CO2 in soil solution are both sources of HCO3– for root uptake. Considering this dilution effect by carbonates, the total incorporated HCO3– comprised 0.15% of C in fruit carbonate after 10 hr of shoot labeling. However, if the incorporated HCO3– during 10 hr of shoot labeling is extrapolated for the whole month of fruit development (i.e. 420-hr photoperiod), fruit carbonate in loess-grown plants incorporated approximately 6.3% more HCO3– than in sand. Therefore, fruit carbonates from plants grown on calcareous soils may yield overestimated 14C ages around 500 yr because of a few percentage uptake of HCO3– by roots. However, the age overestimation because of HCO3– uptake becomes insignificant in fruits older than approximately 11,000 yr due to increasing uncertainties in age determination.

At Cova Eirós, we discovered 13 panels with paintings and engravings that stylistically point to the final moments of the Upper Paleolithic. Scanning electron microscopy with energy dispersive X-ray spectroscopy and Fourier transform Raman spectroscopy were used to identify charcoal as black pigment. Although contamination from medieval fires inside the cave complicates the dating of these pictographs, analyses of unpainted rock backgrounds allowed calculation corrections for contaminated samples. We used plasma oxidation and accelerator mass spectrometry (AMS) to directly radiocarbon (14C) date two charcoal paintings—confirming that the images are more than 9000 yr old. As these paintings superimpose engravings, these 14C dates also provide a minimum age for an engraving at Cova Eirós that is stylistically Final Magdalenian/Epipaleolithic. This is the first known evidence of Paleolithic cave art in Galicia of NW Iberia.

Loess-paleosol sequences (LPS) are valuable archives for Quaternary climate and environmental changes. So far, LPS are generally dated using luminescence, with ~10% uncertainties, or radiocarbon (14C) analyses in the rare cases that charcoal or macrofossils are available. For this study, we determined 14C ages of leaf waxes (long-chain n-alkanes) extracted from the LPS Kurtak in central Siberia. 14C ages range from 16.7 to 22.9 ka cal BP for the last glacial loess and from 24.5 to 35.3 ka cal BP for the paleosol correlated with marine isotope stage (MIS) 3. Overall, this is in good agreement with independent age control based on stratigraphy, infrared stimulated luminescence (IRSL) dating, and 14C dating on charcoal and macrofossils. However, strong cryoturbation and solifluction seem to have affected the MIS 3 paleosol early during MIS 2. Our results corroborate the stratigraphic integrity of leaf waxes, and highlight their potential for dating LPS back to ~35–40 ka BP. Compared to compound-specific 14C analyses, which are very time-consuming and require specialized instrumentation (gas chromatograph with fraction collector), 14C dating of leaf waxes as a whole compound class is relatively quick and straightforward and warrants further investigation as a chronological tool.

This article proposes a solution to the problem of defining the “present” in the BP time scale as 1950. Discouraging the use of “Before Present,” as well as “Before Physics,” and promoting Radiocarbon’s official definition of “BP is understood as a symbol meaning precisely ‘conventional radiocarbon years before AD 1950’” is advised.

We estimate the blank carbon mass over the course of a typical Ramped PyrOx (RPO) analysis (150–1000°C; 5°C×min–1) to be (3.7±0.6) μg C with an Fm value of 0.555±0.042 and a δ13C value of (–29.0±0.1) ‰ VPDB. Additionally, we provide equations for RPO Fm and δ13C blank corrections, including associated error propagation. By comparing RPO mass-weighted mean and independently measured bulk δ13C values for a compilation of environmental samples and standard reference materials (SRMs), we observe a small yet consistent 13C depletion within the RPO instrument (mean–bulk: μ=–0.8‰; ±1σ=0.9‰; n=66). In contrast, because they are fractionation-corrected by definition, mass-weighted mean Fm values accurately match bulk measurements (mean–bulk: μ=0.005; ±1σ=0.014; n=36). Lastly, we show there exists no significant intra-sample δ13C variability across carbonate SRM peaks, indicating minimal mass-dependent kinetic isotope fractionation during RPO analysis. These data are best explained by a difference in activation energy between 13C- and 12C-containing compounds (13–12∆E) of 0.3–1.8 J×mol–1, indicating that blank and mass-balance corrected RPO δ13C values accurately retain carbon source isotope signals to within 1–2‰.

In the present work, we assess the chronology of archaeological sites known as earthen mounds, commonly found at the Pampas biome, among the lowlands of Brazil, Uruguay, and Argentina. We focused on the Pontal da Barra settlement, which is a testimony of the long-term occupation of indigenous groups in the swamp and wet environment of Patos Lagoon, southern Brazil. A Bayesian chronological model based on the radiocarbon (14C) dating of 17 samples of fish otolith, 5 charcoal fragments, and 2 bones (human and dog) allowed determination of the beginning of the occupation as well as the occupational synchronism of the different mounds. The nature of the samples allows us to study the local 14C reservoir effect through the comparison between the group of marine and terrestrial samples, deriving a reservoir offset value of 63±53 14C yr for this particular area, indicating a strong freshwater influence in the lagoon system. We estimate the start of human intervention in the landscapes of southern Patos Lagoon to be around 2200 cal BP, with the most intense activity between 1800 and 1200 cal BP.

The aim of this paper is to evaluate the compatibility between the Holocene relative sea-level (RSL) curves proposed for the Brazilian littoral and mangrove dynamics along a fluvial valley in the state of southern Bahia. This was done integrating geomorphological, sedimentological, palynological, and stable isotopic data from two cores collected at the mouth of the Jucuruçu River and at a site 23 km inland, near the city of Prado, northeastern Brazil. Core PR07, sampled from a fluvial plain at about 4.5±1 m above the RSL, reveals mangrove pollen (5–20%) and estuarine/terrestrial organic matter (δ13C=~–25‰, C/N=7.3–67) between 4.5 m (~7400 cal yr BP) and 1.75 m depth (~5350 cal yr BP). Core PR11, sampled from a mangrove tidal flat, also revealed mangrove pollen taxa (5-28%) since 660 cal yr BP. Core PR07 indicated absence of mangrove pollen and increase of sedimentary organic matter sourced from terrestrial C3 plants (δ13C=~–27‰, C/N=22–159) during the last 5350 cal yr BP. Probably, the changes in vegetation and sedimentary organic matter identified in core PR07 were caused by the combined effects of the RSL fluctuations, with a highstand at about 5350 cal yr BP of 2.7±1.35 m, and changes in fluvial discharge.

Obtaining accurate age determinations from minerals in archaeological ash is a major unsolved issue in radiocarbon (14C) dating. This is because the original 14C content of calcite, the main component of ash, is altered by isotopic exchange. Pyrogenic aragonite, another mineral phase recently discovered in ash, might preserve its 14C signature through time. Using a new method based on density separation and step combustion, we were able to isolate and date aragonitic ash from an archaeological destruction horizon of known age. Here we show that the 14C age of aragonite matches the age of the destruction horizon. Our results demonstrate that pyrogenic aragonite is a short-lived material suitable for 14C dating and directly related to human activities involving the use of fire, thus bearing major implications for the establishment of absolute chronologies for the past 50,000 yr.

Despite their great potential, charred particles of chaff-and-straw temper from daub architecture have very rarely been considered as material suitable for 14C dating. This short paper is intended to change this situation. With this aim in mind, we first present the rationale and objectives of the sampling procedure based on archaeobotanical exploration of prehistoric remains of daub architecture, and then report and discuss the results of a short chronometric exercise based on such samples. The empirical verification of the sampling procedure was based on finds related to the epi-Lengyel culture from Upper Silesia.