Pica 8 is a Late Intermediate Period (AD 900–1450) cemetery located in the Atacama Desert. Burials at the site present unexpectedly high variability in δ13C (–8‰ to –16‰) and δ15N (10‰ to 24‰) values in their skeletal tissues, implying highly diverse diets. There are two possible explanations for this variability: the first is diachronic change in diet while the second involves synchronic sociocultural distinctions. To distinguish between them a radiocarbon (14C) dating program (n=23) was initiated. The presumed importance of marine foods adds the complication of a marine reservoir effect. To address this problem, paired 14C dates were obtained on human bone and camelid textiles from nine graves. The results fall into two groups, one showing an average offset of 117±9 14C yr, and the other no statistically significant offsets. We conclude that the contribution of marine foods to bone collagen at Pica 8 was less than previously supposed. Other factors must be invoked to account for the unusually high human δ15N values at the site. Manuring crops with sea-bird guano emerges as a probable explanation. No relationship with chronology is seen implying the presence of considerable diversity in diets and hence lifeways within the Pica 8 community.

Population growth has been evoked both as a causal factor and consequence of the transition to agriculture. The use of radiocarbon (14C) dates as proxies for population allows for reevaluations of population as a variable in the transition to agriculture. In Korea, numerous rescue excavations during recent decades have offered a wealth of 14C data for this application. A summed probability distribution (SPD) of 14C dates is investigated to reconstruct population trends preceding and following adoptions of food production in prehistoric Korea. Important cultivars were introduced to Korea in two episodes: millets during the Chulmun Period (ca. 6000–1500 BCE) and rice during the Mumun Period (ca. 1500–300 BCE). The SPD suggests that while millet production had little impact on Chulmun populations, a prominent surge in population appears to have followed the introduction of rice. The case in prehistoric Korea demonstrates that the adoption of food production does not lead inevitably towards sustained population growth. Furthermore, the data suggest that the transition towards intensive agriculture need not occur under conditions of population pressure resulting from population growth. Rather, intensive rice farming in prehistoric Korea began during a period of population stagnation.

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.

Over the last few decades, radiocarbon laboratories have used different procedures for measuring a broad range of carbonaceous materials. To produce reliable results, the processes employed for sample processing, graphite target production, and spectrometer measurement must be rigorous, well tested, and reproducible. Most of the procedures have been developed, improved, and published as part of the laboratories’ quality control and research programs, and can be frequently found in the literature. Nevertheless, there are suites of laboratory techniques (or “small useful skills”), products, and other resources that either have never been described in publications, or have been somewhat hidden in much larger scientific articles and reports. We feel that with the rapid rise of newer laboratories and facilities, a set of resourceful suggestions might come in handy. Here we gathered these skill sets that can be used in all aspects of 14C sample processing, with the intention to simplify and expedite procedures, from glass-tube making to graphitization and measurements. We also included some miscellaneous items to help in laboratory setup.

Strombus alatus and Busycon sinistrum are large marine gastropods that are frequently recovered from archaeological contexts in southeastern North America. We previously proposed a reservoir age offset (ΔR) for B. sinistrum from the northern Gulf of Mexico region based on known-age pre-bomb 20th-century specimens. We also reported significant variability in radiocarbon both among and within S. alatus specimens, which precluded a reliable estimation of ΔR for this taxon. In this paper, we present a complementary data set from archaeological contexts to re-evaluate marine reservoir effects in the northern Gulf Coast region at multiple spatial and temporal scales. The new data set consists of a total of 13 14C age determinations from well-associated marine (B. sinistrum and S. alatus) and terrestrial (Odocoileus virginianus) samples from a closed context at the Bayou St. John (1BA21) archaeological site. We suggest a slightly updated ∆R value of –2±53 14C yr for late Holocene-age B. sinistrum from the northern Gulf Coast region. S. alatus, and possibly other species of strombid conchs, are poor candidates for 14C dating due to the highly variable 14C content observed within and among specimens. Though subregional variability in inputs of 14C-depleted waters is likely, life-history factors related to ontogenetic niche and/or habitat shifts appear to be a major influence in shell 14C for S. alatus.

Radiocarbon dating has had profound implications for archaeological understanding. These have been identified as various “revolutions,” with the latest—Bayesian chronological statistical analyses of large datasets—hailed as a “revolution in understanding.” This paper argues that the full implications of radiocarbon (14C) data and interpretation on archaeological theory have yet to be recognized, and it suggests that responses in Britain to earlier revolutions in archaeological understanding offer salutary lessons for contemporary archaeological practice. This paper draws on the work of David Clarke and Colin Renfrew to emphasize the importance of critical considerations of the relationships between archaeological theory and scientific method, and to emphasize that seemingly neutral aspects of archaeological thought are highly laden interpretatively, and have significant implications for the kinds of archaeology that we write.

Systematic investigations and experience from several application projects on small carbon samples over a number of years have resulted in measuring the radiocarbon content of 10 μg C samples with an overall precision of typically 1%. A substantial reduction of the carbon contamination during graphitization was achieved, resulting in 31±30 ng modern and <100 ng 14C-free carbon. Thus, graphitization is no longer the limiting factor because earlier sample preparation steps usually introduce much larger contamination. The method has been extended to a variety of materials and applied to various projects. Realistic conditions for procedure development can only be achieved in the context of applications on true samples; methods developed are the lyophilization of samples in solution, combustion, ultraviolet oxidation, or carbonate hydrolysis with phosphoric acid, which allows to prepare samples for a wide range of applications. Insights gained from systematic investigations and from real applications are presented.

In this work, we present the results of radiocarbon (14C) dating of three historically important objects related to the period of the reign of the Ottoman Empire in Europe. The following objects from the museum collection of the Franciscan Monastery in Fojnica, Bosnia and Herzegovina were 14C dated: (1) paper from the Ahdname (Fojnička ahdnama); (2) textile of the mantel of Fra Anđeo Zvizdović; and (3) paper from the Fojnica Armorial (Fojnički grbovnik). It was assumed that the Ahdname was issued in AD 1463 by the Ottoman Sultan Mehmed II to the Catholic monks and that the Mantel had belonged to Fra Anđeo Zvizdović, who received the Ahdname. The Fojnica Armorial is an important source of the classical heraldry of the Balkans Peninsula, with various estimates of the age. The 14C calibrated ages of the Ahdname are as follows: lower part, cal AD 1430–1465, upper part, cal AD 1665–1808, proving that only the lower part of the Ahdname was original. The 14C calibrated age of the textile from the outer layer of the Mantel is cal AD 1492–1641, somewhat younger than expected, and inner lining even younger, cal AD 1652–1805. Good coincidence between the calibrated age span of the renewed part of the Ahdname and the lining material of the Mantel can suggest that both objects had been renewed around the same time. Two samples of the Fojnica Armorial were dated: thick paper, cal AD 1631–1667 and thin paper, cal AD 1809–1926, showing that the Armorial had been compiled during different periods.

We recently started a systematic approach to determine the reservoir age in southeast Arabia and its dependence on mollusk species and their environment. This part of the study concentrates on local reservoir age and stable isotopes of the lagoonal species Terebralia palustris and Anadara uropigimelana at Khor Kalba, Oman Sea. Environmental and nutritive influences on mollusks are reflected in the radiocarbon and stable isotope signal. We found a local reservoir age of A. uropigimelana of about 940 yr and that of T. palustris as 800 yr. Sclerochronological analyses yielded information about seasonality of growth and death in A. uropigimelana. The modern shell of Periglypta reticulata shares food resources and habitat with Anadara sp., of which we did not find a modern specimen. It provided information on response to changes in temperature in the lagoonal system needed for suitability as reflecting climatic conditions. We were interested in carbon pathways of the mangrove in Kalba and a mangrove planted anew on a former mangrove sediment in Ajman. Being an obvious source of charcoal and food of T. palustris makes this information necessary. Further analyses will be performed to interpret changes in reservoir age in complex lagoonal systems as reaction to environmental variability.

We obtained radiocarbon (14C) dates with accelerator mass spectrometry (AMS) of vascular plant samples and a charcoal sample collected from peat deposits near the prehistoric village site informally designated CR-03 on Carlisle Island in the Islands of Four Mountains group, Alaska, to determine the eruption age of the CR-02 tephra. A fine vitric ash erupted from Okmok caldera, Umnak Island (ca. 2 ka BP) was also discovered in the bog. The ages of the CR-02 tephra and Okmok II ash are estimated to be 1050 and 2000 cal BP, respectively. Because both tephras are distinctive and widespread, these are important chronostratigraphic markers for archaeological sites in this island group. The 14C dates obtained from this bog are 800 years younger than the dates of the charcoal fragments from cultural layers in the Unit 3 of prehistoric village site CR-02 (AMK-0003).

The discovery of the ancient city of Loulan in Xinjiang, China, at the beginning of the 20th century was of great significance for understanding the evolution of culture and civilization in Inner Asia. However, due to the lack of systematic chronological studies, the history of this ancient city remains unclear, particularly the date of its construction and abandonment. Here, we present the results of the first systematic radiocarbon (14C) dating carried out on artifacts from ancient Loulan. Our results show that human activity began as early as 350 cal BC, flourished during the interval from the 1st to 4th centuries AD, and completely disappeared around 600 AD. Most of the buildings in the city were constructed during the Eastern Han Dynasty rather than in Wei/Jin Dynasty, as previously indicated by excavated documents and letters (Hedin 1898; Xiao 2006). The development and flourishing of Loulan coincided with the interval of high ice accumulation and meltwater supply from surrounding mountains. The city began to decline and was finally abandoned following an abrupt decrease in ice accumulation and meltwater supply (Yao et al. 1996; Lauterbach et al. 2014), suggesting that natural climate change was the major factor responsible for the abandonment of Loulan.

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.

Archaeological excavations carried out from 2008 to 2011 at the Lubin stronghold (NW Poland) brought about the discovery of relics in one of the oldest Christian churches in Pomerania (NW Poland). Radiocarbon (14C) analysis of 24 samples of charred wood from the deposits within the stronghold pointed to a chronology spanning from the 10th to 13th centuries, which is consistent with the archaeological evidence. However, the 14C analysis of 12 samples collected from the destruction of the church (erected in 1124 AD according to written accounts) produced a chronology notably older than expected, with a recorded difference of no less than 100 yr. The most probable explanation for this discrepancy seems to be the secondary use of older timber during the construction of the church.

Archaeologists have long examined how the emergence of core polities prompts changes in the settlement patterns of peripheral regions through various processes like warfare, patronage claims, control of ritual rites, and unequal balances of trade. According to historical records, there were 54 small Mahan polities in southwestern Korea, and one of these polities, Baekje, grew to become an ancient state by unifying other polities in the 4th century AD. It is assumed that subsequent changes in the settlement patterns of southwestern Korea were caused directly or indirectly by the expansion of Baekje, but the nature of this presumed influence is not fully explained due to difficulties in establishing chronologies and the limited application of spatial analyses. In this paper, radiocarbon (14C) dates, kernel density estimates, and spatial autocorrelation analyses are used to compare Mahan settlement distributions before and after the rise of the Baekje kingdom. The results demonstrate that the spatial distribution of Mahan settlements changed over time, correlating with the emergence of Baekje statehood, but detailed aspects of the settlement patterns observed in each region were not uniform. Baekje applied various expansion strategies and exerted asymmetrical hegemony based on the conditions and responses of peripheral communities.

Stable carbon isotope ratios were measured on the alpha-cellulose in tree rings of a pine tree (Pinus densiflora) from Yeongwol, Korea. We developed an annual-resolution δ13C series (1835–1905) by correcting the measured data for changes in δ13C of air to minimize non-climatic influences. To investigate the climatic signal in the δ13C series, we performed correlation analysis between δ13C and the Cheugugi climate data. The Cheugugi precipitation data were first recorded by King Sejong (1397–1450) of the Joseon Dynasty. However, the longest set of precipitation data available is the one collected in Seoul (1776–1907). Although many studies support the reliability of the Cheugugi data, no previous studies have investigated the potential of the δ13C signal in tree rings as paleoclimate proxy using the Cheugugi data. Recent precipitation trends in Yeongwol are quite similar to that of Seoul, and we found significant correlations between the Cheugugi data and the δ13C series. We suggest further studies to replicate these results and confirm whether comparing δ13C variations in tree rings and Cheugugi data is a useful method of investigating the potential of the δ13C signal as a paleoclimate proxy in or near the Korean peninsula.

This is a reply to a rejoinder to our work in the Negev Highlands (Shahack-Gross and Finkelstein 2015) recently published by Bruins and van der Plicht in this journal (2017a). It addresses archaeological method and practice related to the way evidence for the timing of dry farming in the arid Negev Highlands, Israel, has been obtained. We highlight issues related to phytolith assemblages and livestock dung found in Negev Highlands sites as an indicator for presence/absence of cereal crops, and briefly discuss methods with which terraced agricultural plots in the region have been dated. We touch upon issues at the core of the scientific method, especially the need for proper controls and the importance of reporting full sets of data. Based on the new data presented by Bruins and van der Plicht (2017a, 2017b) we propose an alternative interpretation for their dating of a single terrace at Horvat Haluqim.

The different categories of samples and their treatments at the radiocarbon (14C) laboratory in Jena, Germany, are described. The Jena 14C laboratory is dedicated to studying the global carbon cycle through the analysis of soil, plant, gas, charcoal, and wood samples. The respective preparation procedures for different samples types are presented, including wet-chemistry pretreatments for soil decalcification, charcoal purification using an acid–base–oxidation procedure (ABOx), and α-cellulose extraction from wood and leaves. In particular, investigations of the background corrections for each sample type are emphasized. Furthermore, an investigation of the contamination resulting from the storage of graphite is presented. Four storage conditions are investigated for storage times up to 30 months.

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.

The Laboratory for the Analysis of Radiocarbon with AMS (LARA) was established at the University of Bern in 2013. Since then, the quality of sample preparation and radiocarbon measurement procedures have been validated for different materials such as plant remains, macrofossils, bulk sediment, charcoals, and wood. This article presents the optimization of sample pretreatment of bones based on protocols described in the literature. The extraction of collagen was performed with an acid-base-acid treatment, gelatinization, coarse filtration, lyophilization, and graphitization. Dating results were validated as satisfactory for the Holocene by investigation of 36 individual samples previously dated by other 14C laboratories including VIRI/SIRI materials and from well-known archaeological contexts. An additional blank contribution for bone treatment was determined by comparison with the preparation of other sample materials. The cases of two outliers from the Holocene were studied in detail.