Archaeological excavations at the Syrian settlement of Tell Qaramel have been conducted since 1999. They are concentrated on remnants of the Protoneolithic and early stages of the Pre-Pottery Neolithic period. The settlement has revealed an extremely rich collection of everyday use of flint, bone, and mostly stone objects, such as decorated chlorite or limestone vessels; shaft straighteners used to stretch wooden arrow shafts, richly decorated in geometrical, zoomorphic, and anthropomorphic patterns; as well as different kinds of stones, querns, mortars, pestles, grinders, polishing plates, celts, and adzes.

Excavations brought the discovery of 5 circular towers. Some 57 charcoal samples were collected during the excavations and dated in the GADAM Centre in Gliwice, Poland. The stratigraphy of the settlement and results of radiocarbon dating testify that these are the oldest such constructions in the world, older than the famous and unique tower in Jericho. They confirm that the Neolithic culture was formed simultaneously in many regions of the Near East, creating a farming culture and establishing settlements with mud and stone architecture and creating the first stages of a proto-urban being.

The Balearic quicklime burials of the Iron Age have been radiocarbon dated. Because the bones found are unsuitable for dating, lime was dated using the titration method, with results indicating that in some samples there is still fossil limestone carbonate present, while other samples suffered from recarbonation. Nevertheless, 14C dates on lime and organic matter agree when both arc present. The titration method allows calculating a consensus value.

Radiocarbon (14C) activity in groundwater can be used to determine subsurface residence time up to ∼40 kyr, providing crucial information on dynamic properties of groundwater and on paleoclimate. However, commonly applied sampling methods for dissolved inorganic carbon (DIC-14C) are prone to low level of modern atmospheric contamination, resulting in underestimation of groundwater ages that cluster around 30–40 kyr. We extract CO2 gas from groundwater using a device originally developed for studies of noble gas radionuclides. Carbon is collected in the gas phase, eliminating the possibility of fostering microbial activities and aqueous chemical reactions during sample storage. This method collects CO2-14C and radiokrypton (81Kr and 85Kr) samples simultaneously. The presence of any shorter-lived 85Kr is used to evaluate the degree of atmospheric contamination during sampling or mixing of young groundwater. Most groundwater samples showed lower CO2-14C activities than those of DIC-14C, presumably due to the absence of atmospheric contamination. Samples with 81Kr age exceeding 150 kyr have no detectable CO2-14C except where mixing sources of young groundwater is suspected. These field data serve as confirmations for the reliability of the newly presented sample collection and CO2-14C method, and for the outstanding roles of radiokrypton isotopes in characterizing old groundwater.

A newly operating accelerator mass spectrometry (AMS) facility such as VERA has to go through an extensive testing phase in order to establish optimal conditions for 14C measurements, especially in the field of archaeological samples where an overall precision of 0.5% is desirable.

We discuss the results of our measurements at the milligram carbon level as they relate to long-term stability, reproducibility, precision and isotope fractionation.

The following is a list of dates obtained since the compilation of our first list in November, 1963. Equipment and operating procedures are the same with the exception that a gas chromatograph has been added to confirm the purity of the methane samples used for dating.

The Radiocarbon Dating Laboratory was established in 1967 at the Department of Nuclear Physics, Comenius University, as part of a program of low level counting research of the department and as a contribution to geophysical, geologic, archaeologic and hydrologie research.

We have made the first measurements without pre-enrichment of 41Ca in terrestrial rock and bone samples using accelerator mass spectrometry. Although the results in tufa deposits from Egypt are in good agreement with the saturation value of 8×10-15 predicted by Raisbeck and Yiou (1979), the average 41Ca:40Ca ratio of 2×10-15 (range: 0.6 to 4.2×10-15) that we measure in modern bone is an order of magnitude lower than that obtained previously by Henning, et al (1987) on a cow bone that was measured using AMS following isotope enrichment. The low value and the variability (more than a factor of seven) of the 41Ca:40Ca ratio in modern bone make the possibility of dating bones using 41Ca unlikely.

The conventional 14C time scale between 11,500 and 22,000 sidereal years has been calibrated by TIMS U/Th dates for corals. Only a few studies have been made for the time beyond this range. Obtaining samples suitable for numerical dating or estimating the reservoir correction of the 14C dates has been difficult, but we do not have these problems with TIMS U/Th dating of interstadial and interglacial lignite, because reservoir corrections are unnecessary.

The dating equipment at the National Physical Laboratory was completed by the summer of 1960. A series of calibration and intercomparison measurements was undertaken however, using the NBS oxalic acid reference standard, a modern wood standard (1850 oak tree) and other material before starting routine measurements toward the end of 1961. All results have been obtained using a 4.5 L copper proportional counter filled with CO2 at a constant density corresponding to standard conditions of 22°C and an absolute pressure of 150 cm Hg. The counter is shielded by 8 in. of steel, 6 in. of paraffin wax containing boric oxide, 23 Geiger counters arranged as two independent groups and finally by 1 in. of mercury.

This article discusses radiocarbon dating results for soils and soil-like systems in the East Antarctic oases, including Schirmacher, Thala Hills, and Larsemann Hills. The organic matter of endolithic and hypolithic systems, soils of wind shelters, and soils under moss-algae vegetation were dated along with micro- and macroprofiles. Organic matter pools formed under extreme climatic conditions and originated not from vascular plants but from cryptogamic organisms, and photoautotrophic microbes have been identified within the oases of the East Antarctica. The organic matter of the most of East Antarctic soils is young and cannot reach a steady state because of the high dynamism in the soil cover due to active erosion. The oldest soil organic matter in East Antarctica was found in the soils formed in wind shelters and endolithic soil-like systems under the protection of consolidated rock surfaces. According to our data, the maximal duration for the formation of organic matter profiles within the oases of East Antarctica is ~500 yr, which is similar to the age determined for High Arctic soils in Eurasia. The absence of older soils, comparable with the Holocene deglaciation, can be due to the extreme conditions resulting in occasional catastrophic events that destroyed the soil organic horizons.

Radiocarbon dating encounters (1) problems of reservoir effects and regional/seasonal variation affecting the chronological reliability of measurements, (2) problems of calibration of measurements via comparison with tree segments of known dendrochronological dates, (3) problems of statistical inference with respect to the data pre- and post-calibration, and (4) problems of the analysis and communication of information to archaeologists, historians, and other interested parties. This paper considers the special characteristics of each of the problem areas indicated in order to improve communication between 14C scientists and the disciplines of archaeology, anthropology, and ancient history.

The following list contains dates of samples measured since our previous list (R, 1975, v 17, p 149-155). As before, age calculations are based on the Libby half-life 5570 ± 30 yr and reported in years before 1950. The modern standard is 0.950 of the activity of NBS oxalic acid.

The C14-dating Laboratory in Trondheim has now been working for one year and a half. The present dating list covers the period from July 1957 to September 1958. The rather small number of datings made during this period is due to a lot of background experiments which have been carried out in the last half-year.

With a few exceptions the datings done before the period mentioned have been previously published (Marstrander, 1956–1957; Nydal and Sigmond, 1957; Skjelsvik and others, 1957–1958).

This date list includes those series of samples completed in this laboratory as of August 1968. The B.P. ages are based upon A.D. 1950, and are calculated with a half-life value of 5568 yr. All samples were counted at least twice for periods of not less than 1000 min each. Errors quoted are derived from measurement of sample, background, and modern age calibration, but do not include any half-life error. All samples were pretreated with 3N HC1, and some, where noted, were given additional pretreatment with 2% NaOH for the removal of possible humic contaminants.

This list includes many of the datings done from September 1964 to October 1965. The instruments and techniques used for this work are essentially the same as those used previously (Gakushuin III). Bone samples were dated on the organic materials obtained by the following procedure. After washing with distilled water the powdered bone samples were boiled with 10% H2SO4 solution 10 to 40 hours. The extract, a clear solution, was exaporated to almost dryness, and, after concentrated H2SO4 was added, heating was continued until most of the organic compounds became insoluble carbonized or polymerized material. The black residue was washed in water and treated as the usual charcoal sample for dating.

Radiocarbon (14C) can be used to build absolute chronologies and reconstruct ocean ventilation over the last 40 ka. Sample size requirements have restricted 14C measurements in marine cores with low foraminifer content, impeding 14C-based studies focused on abrupt climate events. Recent developments have demonstrated that small-sized foraminifer samples can now be dated using a gas introduction system at the cost of a small decrease in precision. We explore the potential of gas measurements on benthic and planktonic foraminifers from core SU90-08 (43°03′1″N, 30°02′5″W, 3080 m). Gas measurements are accurate, reproducible within 2σ uncertainty and comparable to graphite measurements. Both techniques yield negative 14C benthic-planktonic (B-P) age-offsets after Heinrich event 1. We argue that negative B-P ages result from bioturbation and changes in foraminifer abundances, with the chance of negative B-P especially increased when the 14C age gradient between the deep and surface waters is decreased. Small-sized 14C measurements seem to capture the variance of the foraminifera age distribution, revealing the active mixing in those archives. Sediment deposition and mixing effects possibly pose a greater obstacle for past 14C-based dating and ocean ventilation reconstructions than the measurement precision itself, particularly in relatively low sedimentation rate settings.

This laboratory is now a part of the Bureau of Economic Geology, The University of Texas at Austin. The present list reports C14 measurements made in dating projects completed in the year ending November, 1967, and some measurements for projects still in progress. Age calculations are based on C14 half-life of 5568 yr and a modern standard of 95% of NBS oxalic acid. The deviations reported are based on the counting statistics of the sample, background, and modern, and are ± 1σ except that when the sample count approaches either the modern or the background, 2σ limits are reported. The laboratory continues to use liquid scintillation counting of benzene, using Li2C2 and vanadium activated catalyst in preparation, as described in Texas IV and earlier lists. Chemical yields now average 85%.

Rightmire's caliche dating (done for an M.A. thesis in the Dept. of Geol.) is the principal project reported in this list; in addition to the research he prepared the samples in our laboratory and wrote the statements which accompany the list. Valastro is in charge of all technical operations in the laboratory, and he and Davis share the administrative responsibilities. Davis, who handles sample screening (with the aid of an Advisory Committee) and archaeological appraisal, compiled the list.

The prehistoric site of Cornia Nou (Menorca) features a number of well-preserved architectural structures belonging to the Talayotic culture. Over the last 6 yr, a team linked to the Museum of Menorca has conducted an archaeological excavation project of a large rectangular building attached to the south side of a substantial and massive talayot, which is considered the western talayot. The main objective of this paper is to present the chronological framework of this building, specifying the period of use and the time of abandonment of the building, as well as the dating of the different phases of its construction. A total of 27 14C analyses were obtained from samples of the stratigraphic layers and architectonic structures inside the South Building (SB). This research has provided new insights concerning the early stages of the Talayotic culture. The 14C dates allow us to place the first recorded occupation phase of the SB in an interval dated within 1100–900 BC (phase 4). A second phase in the occupation of the SB dates to ∼900–800 BC (phase 5). A final occupation phase could be situated between 800–600 BC (phase 6). However, this record provides evidence to suggest that the construction of the west talayot may pertain to a time before the beginning of the 1st millennium cal BC.

The following list covers samples measured at the Uppsala radiocarbon laboratory during 1960. The technique used has been described by the senior author (Olsson, 1958). Pretreatment has not been changed since the last dating list was published (Uppsala II).

Archaeological sites in the Canadian Arctic often contain substantial quantities of marine mammal bones and in some cases completely lack terrestrial mammal bones. A distrust of radiocarbon (14C) dates on marine mammal bones among Arctic archaeologists has caused many sites to be insufficiently dated. The goal of this study was to investigate the marine reservoir effect on Atlantic walrus in the Foxe Basin region of the Canadian Arctic through a two-pronged approach: dating of live-harvested specimens of known age collected prior to AD 1955 and dating of pairs of animal remains (walrus and caribou) from stratigraphically contemporaneous levels within archaeological features. 14C dates on pre-bomb, live-harvested walrus indicate that a ΔR value of 160±50 yr be used in calibrating dates on walrus from this region. These results differed significantly from a similar set of pre-bomb mollusks, which argues against applying mollusk-based corrections to marine mammals. The results of comparative dating of caribou and walrus from archaeological features provided maximum estimates of reservoir ages that were more varied than the directly measured ages. Although about half of inferred ΔR values overlap the museum specimen results, the others indicate that the assumption of contemporaneity does not hold true.