The extension of the bristlecone pine chronology, which is, thus far, the only complete tree-ring-dated series that extends beyond 6000 bc and which is used for the calibration of radiocarbon dates, has been going on over the past 22 years, that is, ever since Schulman (1956; 1958) established the extremely old ages of the bristlecone pine. The few people in this world who search for very old wood samples to extend a dendrochronology may appreciate a method of establishing quickly the approximate ages of the samples.

Kvartett is a new liquid scintillation counting (LSC) system for radiocarbon dating that takes a radical departure from conventional systems to obtain a compact, low-level counting system measuring four samples simultaneously. Each sample vial, inside the well of a large NaI(Tl) guard-counter crystal (facing down), sits on top of a vertical PMT. The fourfold counting capacity can be used to increase the number of samples being dated or to get higher precision. The increased throughput helps to keep a rigid quality-control standard. We monitored the background count rate almost continuously for 7 months, and measured the count rate of a standard repeatedly for 2 months. The results show the background and system reproducibility to be stable.

Given the fluctuating nature of the radiocarbon calibration curve, the precision of single 14C dates on the calendar timescale is limited. However, 14C dating combined with dendrochronology enabled us to date timbers found in the Tisza River, Hungary, during the dry period of summer 2003. Routine preparation of wood samples gave 14C results spread over 4 centuries. By extracting alpha-cellulose from the samples, 2 distinct and relatively narrow historical time periods were obtained: the first period (AD 1505–1595 and 1612–1673, respectively) coincided with the Turkish occupation period, while the second interval (1733–1813) obtained in the case of 2 samples did not exclude the existence of another bridge constructed later. The dendrochronological data confirmed that the bridge was constructed from oak timbers felled between 1558 and 1565. The 14C and dendrochronological dates correspond with the date of a letter written in 1562 by Antal Verancsics, Bishop of Eger, mentioning the construction of the first bridge. In conclusion, the archaeological excavation revealed proof of the first historically attested wooden bridge over the Tisza River.

Estuaries and deltas are crucial zones to better understand the interactions between continents and oceans, and to characterize the mineralization and burial of different sources of organic matter (OM) and their effect on the carbon cycle. In the present study, we focus on the continental shelf of the northwest Mediterranean Sea near the Rhône river delta. Sediment cores were collected and pore waters were sampled at different depths at one station (Station E) located on this shelf. For each layer, measurements of dissolved inorganic carbon concentration (DIC) and its isotopic composition (δ 13C and Δ14C) were conducted and a mixing model was applied to target the original signature of the mineralized OM. The calculated δ 13C signature of the mineralized organic matter is in accordance with previous results with a δ 13COM of marine origin that is not significantly impacted by the terrestrial particulate inputs from the river. The evolution with depth of Δ14C shows two different trends indicating two different Δ14C signatures for the mineralised OM. In the first 15 cm, the mineralized OM is modern with a Δ14COM = 100 ± 17‰ and corresponds to the OM produced during the nuclear period of the last 50 years. Deeper in the sediment, the result is very different with a depleted value Δ14COM = –172 ± 60‰ which corresponds to the pre-nuclear period. In these two cases, the marine substrate was under the influence of the local marine reservoir effect with more extreme Δ14C results. These differences can be largely explained by the influence of the river plume on the local marine DIC during these two periods.

With >40 14C dates, mainly on bones and charcoal, the site at Son Mas is the only megalithic sanctuary on the Balearic Islands that has been dated by 14C in detail. Although soil erosion made stratigraphy difficult and the monument was cleaned out regularly during its long use, the results demonstrate that the site was occupied from the Pretalayotic (Chalcolithic) until the Roman period. The aim of this study was not only to date the construction and the use of the sanctuary, but also to correlate this monument, by means of dispersion diagrams, with the other prehistoric sites situated within the same valley. The dates were also used to compare the site with the generally accepted chronology of the Balearic archipelago (Mallorca, Menorca, Ibiza and Formentera).

The renewal of east Atlantic deep water and its large-scale circulation and mixing have been studied in observed distributions of temperature, silicate, ΣCO2, and 14C. 14C variations in northeast Atlantic deep water below 3500m depth are small. Δ14C values range from − 100‰ to −125‰. 14C bottom water concentrations decrease from Δ14C =−117‰ in the Sierra Leone Basin to Δ14C = − 123‰ in the Iberian Basin and are consistent with a mean northward bottom water flow. The characteristic of the water that flows from the west Atlantic through the Romanche Trench into the east Atlantic was determined by inspection of θ/Δ14C and θ/SiO2 diagrams. A mean potential temperature of θ = 1.50 ± .05°C was found for the inflowing water. A multi-box model including circulation, mixing, and chemical source terms in the deep water has been formulated. Linear programing and least-squares techniques have been used to obtain the transport and source parameters of the model from the observed tracer fields. Model calculations reveal an inflow through the Romanche Trench from the west Atlantic, which predominates over any other inflow, of (5 ± 2) Sv (potential temperature 1.50°C), a convective turnover of (150 ± 50) years and a vertical apparent diffusivity of (4 ± 1) cm2/s. Chemical source terms are in the expected ranges.

This article uses age-depth models based on 29 accelerator mass spectrometry (AMS) dates from charred plant macroremains (seeds, chaff), wood charcoal, and snail shells found in two moats from the settlement Fidvár near Vráble (SW Slovakia) to improve the absolute chronology of the Early Bronze Age in central Europe. The charred macroremains were taxonomically identified to species or genus level and the lifespan of the objects and the archaeological context were considered carefully. The selected snail shells were identified to provide reliable age information. This study demonstrates that under certain conditions, ditch archives can be well suited to contribute to archaeological chronologies. For the first time, the transition from the Hatvan to the Únětice period is dated absolutely.

The present list contains dates of geologic samples from the southern part of the Karelian ASSR and partly from the northwest Leningrad Region, USSR, made in 1969-1975.

More than 70 logboats are known in Lithuania and about half of them date before 1800 cal AD. This paper reviews these more ancient logboats, which were discovered in the beds of former or still existing lakes and rivers and present new radiocarbon (14C) dates and wood taxa identifications. Special attention is paid to the logboat found at Šventoji 58, which is at present the oldest 14C-dated (2895–2640 cal BC) logboat found East of the Baltic Sea. Most logboats from the pre-1800s period were 14C dated to medieval and early modern periods and they were made out of pine and oak wood. From a very scarce dataset available it seems that oak wood was introduced into logboat building by Neolithic people, who also brought new technologies in stone tool production. We also noted that 14C dating does not confirm the logboat typology suggested in earlier studies.

We analyzed rare wooden Komainu found at Akagami Shrine in Akita prefecture, Japan. The formation of historical objects is often thoroughly recorded in documents, although the formation age of this particular Komainu sculpture is still unknown due to its antiquity. Thus, age determination exercises have been conducted using radiocarbon (14C)-wiggle-matching techniques. Although only a limited quantity was available for sampling, we have successfully measured 14C samples in the sculptures along with several sets of tree rings. We interpret the Komainu sculptures age considering the age of the trees and the result obtained from the wooden construction materials used for the Akagami shrine. The results obtained from Komainu show a range from 550 CE to 1020 CE, which is consistent with the dates of the shrine’s formation. Thus, the multiple 14C-wiggle-matching method can determine precise calendar ages of wood, as well as provide some supportive information for the periods when there are no reliable historical documents.

The site area of Erimi-Laonin tou Porakou (Limassol, Cyprus) has been surveyed and systematically excavated since 2007 as a joint research project of the University of Florence and the Department of Antiquities of Cyprus. A focused investigation was dedicated to analyzing funerary evidence from the southern Cemetery (Area E), where 7 single-chamber graves were excavated. The offering goods assemblages from the burials point to a general date ranging from Early to Late Bronze Age I, and draw a sequence of use that is contemporary to the stratigraphic deposits from the top mound Workshop Complex (Area A). During the 2010 field season, charcoal samples from the Workshop Complex and bone samples from the skeleton remains of 2 burials (tombs 228, 230) were opportunely taken for radiocarbon analyses. 14C dating was performed at the AMS-IBA Tandetron accelerator of the INFN-LABEC Laboratory in Florence. This paper will discuss the results of the 14C analyses and compare them with the archaeological evidence in order to outline a chronological sequence for the settlement and cemetery areas at Erimi-Laonin tou Porakou, thus collecting further data on the development and pattern of occupation of the Early to Late Cypriote period in the Kourion area.

We report on a review of 14C production and release from the nuclear industry in the United Kingdom (UK). Using earlier predictions (Bush, White and Smith 1984) it is estimated that a total of 1764 TBq of 14C would have been produced in UK graphite-moderated reactors up to the end of 1995, and 135 TBq of this total would have been released. Release rates, based on reported discharges, of 5.1 and 0.93 TBq GW(e)a-1 have been derived for Magnox reactors and Advanced Gas Cooled Reactors (AGRs), respectively. Using these new figures, cumulative discharges of 14C up to 1995 from reactors have been estimated at 531 TBq. The combination of these reactor discharges and the reported discharges from Sellafield (388 TBq) and Amersham (52 TBq) suggest a total cumulative release of 971 TBq of 14C up to the end of 1995.

Variability in temperature and 14C levels are recorded in coralline aragonite that grew in the Gulf Stream during the past four centuries. In particular, 18O/16O ratios reflect a decrease of ca 1°C in surface water temperature during the latter part of the Little Ice age. 14C levels also rose in the surface waters of the Gulf Stream and in atmospheric CO2 during the Maunder minimum. These observations indicate that ocean circulation may have been significantly different in the North Atlantic around the beginning of the 18th century.

The recent progress in radiocarbon dating of the prehistoric cultural complexes in the Russian Far East is discussed against the background of ancient chronologies for greater East Asia. Since 1997, the wide use of accelerator mass spectrometry (AMS) radiocarbon dating along with the continuation of conventional dating has allowed us to establish the age of several key Paleolithic, Neolithic, and Paleometal sites. It has also contributed to advancing a deeper understanding of the timing for the beginning of pottery production, maritime adaptation, and agriculture, and several other important issues in prehistoric chronology for the studied region. Reservoir age correction values for the Japan and Okhotsk seas are now used to adjust the age for samples of marine origin. Some of the cultural-chronological models for prehistoric far eastern Russian complexes put forward in the last 10 yr lack a solid basis, and are critically evaluated herein.

We have investigated the possibility of direct accelerator mass spectrometry radiocarbon (AMS 14C) measurement of carbonate samples at ANSTO using the STAR 2 MV tandem accelerator. Each carbonate sample was powdered, mixed with metal powder and pressed into an aluminum cathode for direct carbonate measurement by AMS 14C. Of the three high-purity metal powders (Fe, Nb, and Ag) used in our investigation, Nb was found to be the best metal, which delivered higher carbon beam currents and lower background. Beam currents for targets containing the optimal carbonate mass of 1.5–2.0 mg were ∼8% of those obtained from graphite targets of standard size (>0.5 mg C). Typical measured blank for Carrara marble (IAEA-C1) of ∼40 ka was obtained. Background-corrected 14C values of carbonate targets agreed well with their associated values obtained from high-precision analysis of graphite targets within 2σ uncertainties. Typical precision of this rapid AMS analysis was ∼1% for samples <8 ka. Despite lower precision for carbonate target ages (compared to standard graphite target ages), these ages are useful for palaeobiological applications where a large number of dates are required, such as time-averaging studies.

My path to the invention of accelerator mass spectrometry—now just called AMS—was quirky and extraordinary, and it is a saga worth telling, particularly for young people who may have an oversimplified image of how progress in science is actually made. It was an adventurous journey, and like many adventures, it was often uncomfortable, haphazard, and frequently characterized by a feeling of being lost. In retrospect, the only reason I set out on this journey was my belief that I didn't know much about finding my path in physics, and that the best I could do was to follow the lead of the great physicist Luis Alvarez. He had an incredible ability to create new and ingenious projects that led in new directions, and I wanted to understand how he did that. So I had decided that I would work with him on any new idea he came up with, even if it inconvenienced the rest of my life. And true to my expectations, while working with Luie (that's what he wanted everyone to call him), I often felt like Odysseus, tossed between distant shores by capricious gods.

The following list includes some measurements made during 1978 and 1979 in the radiocarbon laboratory of the Ecole Nationale Supérieure de Géologie Appliquée et de Prospection Minière (ENSG) de Nancy. Equipment, measurement and treatment of samples are as reported previously (R, 1979, v 21, p 453-464) where the sample is synthesized to benzene. Radiocarbon ages are calculated using the 14C half-life of 5568 years and 95% activity of NBS oxalic acid is used as modern standard. Anthracite coal and Merck commercial benzene are used for the dead carbon run.

This date list consists of some of the samples measuredsince summer 1965. For the routine measurements thesame technique and equipment as described earlierwas used (Bern IV).

Radiocarbon dating of closely associated marine mollusk shells and terrestrial material (charred wood or bone) collected from archaeological contexts on Tenerife and Fuerteventura islands allowed us to quantify the marine 14C reservoir effect (ΔR) around the Canary Archipelago. Coastal Fuerteventura has a positive weighted mean ΔR value of +185 ± 30 14C yr, while for Tenerife a range of negative and positive values was obtained, resulting in a ΔR weighted mean value of 0 ± 35 14C yr. These values are in accordance with the hydrodynamic system present off the Canary Islands characterized by a coastal upwelling regime that affects the eastern islands (Fuerteventura and Lanzarote) but not the other islands of the archipelago, namely Tenerife. Because of this oceanographic pattern, we recommend the extrapolation of these results to the remaining islands of the archipelago, i.e. the first value must be used for the eastern islands, while for the central and western islands the acceptable ΔR value is 0 ± 35 14C yr.