We have carried out a multiproxy analysis of high-resolution eutrophic peat/mud, sand dune, and loess/paleosol sequences covering the Holocene period in both southern and northern China, in order to test the hypothesis of a time-transgressive Holocene optimum in the East Asian monsoon area (An et al. 2000). Samples were radiocarbon dated to establish the chronology. Our results indicate that the Holocene optimum occurred between ∼10,000–5000 cal yr ago in both southern and northern China, consistent with a global pattern rather than simply a local expression. Our data also support the conclusion that the evolution of Holocene climate in China is consistent with changes in Northern Hemisphere solar radiation.

The aim of this article is to discuss radiocarbon dating offsets due to freshwater and marine reservoir effects (FRE and MRE, respectively) in the southeastern Baltic. Thirty-six 14C dates from Lithuanian coastal and inland Subneolithic, Neolithic, and Bronze Age sites as well as two Mesolithic-Neolithic cemeteries are presented here. Accelerator mass spectrometry (AMS) dates, sometimes paired or tripled, have been obtained on samples of various origin, foodcrusts, or visible charred deposits adhering to the surfaces of ceramic vessel walls were also dated and investigated for stable isotope signals. The results argue for a significant freshwater component in the food processed in ceramic vessels during the Subneolithic and Neolithic. Paired dating of ungulate and human bones at the Spiginas and Donkalnis cemeteries (6300–1900 cal BC) does not suggest an FRE, although stable isotope data on human bone collagen strongly suggest a large input of freshwater food in the diet. An FRE in the order of 320–510 yr was estimated for the Šventoji paleolagoon around 3000 cal BC. At the same time, the FRE of the Curonian Lagoon could be larger as implied by large apparent 14C ages of modern pike-perch (981 ± 30 BP) and bream (738 ± 30 BP) bones as well as “foodcrust” offsets (650–530 yr) at Nida (3500–2500 cal BC). An MRE of 190 ± 43 yr was estimated for the southeastern coast of the Littorina Sea according to offsets between dates of seal bones and terrestrial samples at Nida and Šventoji. Any FRE at Lake Kretuonas remains uncertain due to the limited work to date.

The relative Bronze Age chronology for Scandinavia was established as early as 1885. It is traditionally divided into 6 periods (I–VI). Earlier attempts to make an absolute Bronze Age chronology for southern Scandinavia were derived from burials and settlements and were mainly based on radiocarbon-dated charcoal or carbonized cereals, often with undefined archaeological periods. Here, we present high-precision 14C dating on burials with well-defined associated archaeological periods in order to improve the absolute chronology of the Danish Bronze Age. Our results are in broad agreement with the traditional absolute chronology of the Danish Bronze Age. However, our results do indicate that the onset of period III likely occurred earlier than previously thought.

Annual radiocarbon from a massive Porites lutea coral collected from Hon Tre Island, Vietnam, South China Sea (SCS) was analyzed over a ~100-yr-long period from AD 1900 to 1986. The pre-bomb results from 1900–1953 show a steady Δ14C value of –54.4±1.8‰ (n=60). These values are similar to coral records located in the central and southern SCS and from Indonesian waters, but are lower than those from Japan. Following the input of anthropogenic bomb 14C, our results show a sharp increase in Δ14C from 1960, reaching a peak value of 155.3‰ in 1973. The Hon Tre Island post-bomb Δ14C values are lower than those of other corals located in the SCS and Japan, but higher compared to those in the Indonesian Seas. This study infers a seasonal input of upwelled water depleted in 14C from the deeper SCS basin that originates from the tropical Pacific via the Luzon Strait. The bifurcation of the North Equatorial Current feeds the surface and intermediate currents in the SCS and Makassar Strait region. However, unlike the Makassar site, this study’s coral Δ14C does not receive lower 14C water from the South Pacific Equatorial Current. The Vietnam record therefore represents a unique oceanographic position, reflecting the seasonal influence of older, deeper SCS waters that upwell periodically in this area and have modified the surface waters locally in this region over the last 100 yr.

The influence of geothermally derived carbon on the radiocarbon dating of human bone from archaeological sites is poorly understood and has rarely been rigorously examined. This study identifies a previously unknown reservoir effect at the archaeological site of Klin-Yar in the Russian North Caucasus. AMS-dated human bones yielded results that were older than expected when compared with dates of coins found in the same grave contexts. We investigated the reasons for this offset by AMS dating modern plant, fish, and water samples to examine the source of the old carbon. We identified a potential source in geothermally derived riverine and spring water, with an apparent age of several thousand years, and hypothesize that carbon from here is being transferred through the food chain to humans. If humans consume resources from the local rivers, such as fish, then they ought to be affected by this reservoir offset. An extensive analysis of carbon and nitrogen isotopes of human and animal bone showed evidence for a mixed diet that may be masking the amount of freshwater-derived protein being consumed. Due to the highly variable nature of the 14C offset (0 to ∼350 yr), no suitable average correction factor is applicable to correct for the human dates at the site. A 14C chronology based on dates obtained from terrestrial ungulate bones, which we subsequently obtained, is instead a more reliable indicator of age.

A C14-dating installation was operated in the Physics Department, Trinity College, Dublin, from early 1958 until early 1960, by I. R. McAulay. Construction and testing of the apparatus had occupied 15 months previous to this. Material for dating was selected and pretreated by W. A. Watts, who also collected and submitted the samples and carried out pollen analyses except where the contrary is stated in the text. The project was a short-term one with two main aims; to obtain a few key archaeologic dates, particularly in the Neolithic, to help orientate chronologic discussion; and to test the validity of the pollen zonation for the post-Atlantic of Mitchell (1956).

The dating of alluvial deposits is frequently hampered by a lack of good-quality charcoal or other material for radiocarbon samples. We have dated two sites in southeastern Australia using traditional radiometric methods with minimal pretreatment. Results yielded an inconsistent chronology, affected by contamination with younger humic materials. A more consistent and older chronology was achieved using AMS dating of rigorously pretreated samples of fine-grained charcoal. The results have important implications for the radiocarbon dating of many Late Quaternary stratigraphic sequences with low charcoal abundance.

14C is one of the most important anthropogenic radionuclides released to the environment by human activities. Weapon testing raised the 14C concentration in the atmosphere and biosphere to +100% above the natural level. This excess of atmospheric C at present decreases with a half-life of ca 7 years. Recently, a new source of artificially produced 14C in nuclear reactors has become important. Since 1967, the Bratislava 14C laboratory has been measuring 14C in atmospheric 14CO2 and in a variety of biospheric samples in densely populated areas and in areas close to nuclear power plants. We have been able to identify a heavy-water reactor and the pressurized water reactors as sources of anthropogenic 14C. 14C concentrations show typical seasonal variations. These data are supported by measurements of 3H and 85Kr in the same locations. Results of calculations of future levels of anthropogenic 14C in the environment due to increasing nuclear reactor installations are presented.

Vindija cave in Croatia is famous for the Neanderthal bones found in layer G of its sediment profile. Radiocarbon dating has been performed mainly on this layer due to the great interest in its fossils. In addition to Neanderthal remains, the sediment in layer G contains bones from the cave bear. Cave bear bones are found also in other layers of the sediment profile and offer the possibility of studying the bears' evolutionary mode. Therefore, we tried to determine the time span covered by the entire profile. The U/Th age determination method was applied to cave bear bones from different layers of the profile. For the younger part of the profile, the U/Th ages were compared with the results of the 14C and the amino-acid racemization method. The agreement of the different methods indicates that closed-system behavior can be assumed for the fossil bones from Vindija cave. From this finding it may be deduced that bones from the lower sediment layers are also closed systems and that the U/Th ages of these layers are reliable. This conclusion is corroborated by the stratigraphy of the cave profile.

Vogel, Nelson and Southon (1987) determined that the total-system 14C background values in catalytically reduced graphitic carbon samples of 500 mg or less were inversely proportional to their weights. We have used wood reportedly of Pliocene age (i.e., 14C “dead”) to further examine this relation. Our observations are consistent with the conclusions of Vogel, Nelson and Southon (1987). It appears that contamination can be characterized as if a constant level of modern carbon is being added. We also report a significant overall net reduction in total system background values ca. 45% for combusted samples from levels previously reported by Vogel, Nelson and Southon (1987).

The measurements reported in this list have been made in the Isotope Laboratory of the Institute of Geophysics during 1963 and are a continuation of the work reported previously (UCLA I and UCLA II). The same counting procedure—CO2 proportional counting at 1 atm pressure in a 7.5 L counter with three energy channels—continues in use. No barometric effect on the background has been observed, presumably because of the combination of fairly constant barometric pressure in this area and the location of the equipment on the ground floor of a five storey building. Dates continue to be calculated on the basis of a C14 half life of 5568 yr according to the decision of the 1962 Cambridge Conference (Godwin, 1962). The modern standard has been taken as 95% of NBS oxalic acid for all organic samples, while for carbonate material such as shells and tufa, dates have been computed on the basis of estimates of the corresponding contemporary C14 activity (Broecker and Walton, 1959) as indicated in the description accompanying the results.

When did the trade in lucrative spices from South Asia to the West commence? Recent organic residue analyses performed on small early Iron Age (11th–late 10th century BCE) Phoenician clay flasks provide the first concrete archaeological evidence that such sustainable trade took place much earlier than hitherto suspected. The analysis shows that several of the flasks contained cinnamon, which in this period could only have originated in South/Southeast Asia. Here, we first summarize the rationale and results of that study. Subsequently, we provide an updated review of all sources of data relevant to the question at hand—archaeological, analytical, and textual. Finally, we offer suggestions for future research on the Asian spice trade with the West.

This list includes most of the measurements made since the beginning of the compilation of our previous list (R, 1983, v 25, p 59–126), in 1982 and 1983, as well as some earlier measurements of extended geologic or archaeologic studies.

Diet can play a significant role in anomalous radiocarbon ages derived from bone and other tissues when the food web incorporates depleted 14C reservoirs, such as the marine environment. Dietary effects from a post-bomb carbon variation have also been found in modern invertebrates and populations of Rattus exulans (Beavan and Sparks 1998). We now present the effect on absolute percent modern (pMC) and the conventional radiocarbon age (CRA) of a modern aquatic/terrestrial food web in a volcanic zone of the North Island, New Zealand. At Lake Taupo, geothermal venting transfers 14C depleted carbon to lake waters, which aquatic plants fix into the food chain; depleted 14C is shown to then pass on to shellfish, waterfowl, and Norway rat (Rattus norvegicus). The geothermally induced 14C variations from modern atmospheric pMC and CRA can increase apparent 14C ages by >2000 years.

This paper presents radiocarbon results from modern South Pacific corals from the Marquesas Islands, Vanuatu, Papua New Guinea (PNG), and Easter Island. All of the measurements are from pre-bomb Porites corals that lived during the 1940s and 1950s. The data reflect subannual to multiannual surface ocean 14C variability and allow for precise, unambiguous reservoir age determinations. The results are compared with published values from other coral records throughout the South Pacific, with striking consistency. By comparisons with other published values, we identify 3 South Pacific regions with uniform pre-bomb reservoir ages (1945 to 1955). These are 1) the Central Equatorial South Pacific (361.6 − 8.2 14C yr, 2 σ); 2) the Western Equatorial South Pacific (322.1 − 8.6 14C yr, 2 σ); and 3) the subtropical Pacific (266.8 − 13.8 14C yr, 2 σ).

We report here the first radiocarbon dating of blood residues on prehistoric stone tools. The residues found on two stone artifacts were subjected to various exploratory biochemical techniques to identify the species from which they were derived and to separate a suitable sample for dating by accelerator mass spectrometry. Although these techniques need much further development and detailed testing, the ages obtained in this first study were consistent with other data, indicating that the concept is viable. For the first time, the time of use of stone tools has been found directly, rather than by stratigraphic or other archaeologic inferential techniques.

New ΔR values are presented for 10 known-age shells from the Kimberley region of northwest Australia. Previous estimates of ΔR for the Kimberley region are based on only 6 individual shell specimens with dates of live collection known only to within 50 yr (Bowman 1985a). Here, we describe the results of our recent attempts to constrain ΔR variability for this region by dating a suite of known-age pre-AD 1950 shell samples from the Australian Museum and Museum Victoria. A regional ΔR of 58 ± 17 14C yr for open waters between Broome and Cape Leveque is recommended based on 7 of these specimens. The criteria used to select shells for dating and inclusion in the regional mean are discussed.

Many of the problems inherent with conventional 14C dating of lake and peat deposits are eliminated by AMS dating of pollen concentrates. Published work describes production of pollen concentrates through expulsion of most of the deposit matrix by repeated deflocculation, selective sieving and final retention of the largest subfossil pollen taxa. Less suited to pollen concentrate production are the highly organic peats and lake muds from the British Isles and Europe. In this study we tested the combined effectiveness of physical, chemical and microbiological degradation and elimination techniques for pollen concentrate production on highly organic peats and a lake mud. We also reviewed methods of enhancing concentrations of smaller sub-fossil pollen grains. Here we present a novel method of assessing AMS dating precision of pollen concentrates by comparing their calibrated dates with a volcanic event of known historical age.

A preliminary review is given of the evaluation of the International Cross-Calibration Radiocarbon Data. Consensus values and standard errors are D14C = 508.1 ± 2.0% (ANU Sucrose) and Δ = −2.5 ± 1.5% (1850 Wood). Reporting format follows recommendations of Stuiver and Polach (1977).