The paper describes a study undertaken to examine the dispersion pattern of gaseous emissions, as indicated by 14C uptake in natural materials, around the nuclear reprocessing plant at Sellafield, Cumbria, UK. The extent and directional dispersion of the released 14C is established and its variability over an extended period assessed. Results of measurements taken during three sampling seasons (1981, 1982, 1983) of the 14C activity in hawthorn berries collected over a wide area are presented and the dispersion pattern contours constructed from them are examined. Only limited agreement of the results with the theoretical relationship 1/r is found and both meteorology and topography are seen to be important in determining the shape of the observed patterns.

The present list includes 74 dates of geologic samples determined using the liquid scintillation 14C method at the Geobiochemical sector of the Institute of Zoology and Botany, Academy of Sciences, Estonian SSR.

Results presented in this date list have been obtained from Jan 1977 to Dec 1977, but some earlier measurements are also included. All calculations are based on a contemporary value equal to 0.95 of the activity of NBS oxalic acid standard and on the Libby value for the half-life of radiocarbon. Ages are reported as conventional radiocarbon dates in years before AD 1950. No corrections for 13C/12C ratio were made for measurements reported in this list. Errors quoted (±1σ) included estimated overall standard deviations of count rates of the unknown sample, contemporary standard and background (Pazdur & Walanus, 1979). Counting equipment and experimental procedures have been described earlier (Mościcki & Zastawny, 1976, 1977; Pazdur et al, 1978; Pazdur & Pazdur, 1979a). Sample descriptions are based on information provided by the submitters.

Nitrogenous compounds of soil organic matter constitute a major N reservoir on Earth. Both the world food protein supply produced by agriculture and the global contamination by reactive nitrogen species rely on the dynamics of these compounds. To investigate their dynamics, we used both natural 13C labeling and accelerator mass spectrometry (AMS) 14C dating of the α-carboxyl amino carbon, which is specific of the amino acid fraction that was extracted from bulk soil organic matter by ninhydrin hydrolysis. We applied this isotopic approach to investigate the age of carboxyl carbon in a maize-cultivated Cambisol chronosequence. Based on a few measurements, we demonstrate the feasibility of this new compound-specific method of investigation of soil carbon dynamics. We show that soil organic matter amino acids can be split into two very distinct dynamic compartments: the majority having a mean age of a few years and a minority having a mean carbon age of several millennia. The latter fraction can be either strongly stabilized in soils, or can arise from microbial utilization of old carbon resources, as predicted by the priming effect theory.

In January 1975 a radiocarbon dating laboratory was established at the Marine Resources Research Institute for geochemical and geologic studies. A liquid scintillation system is employed according to the method of Noakes, Kim, and Akers (1967). A Searle (Nuclear Chicago) Isocap 300 liquid scintillation counter is currently being used for counting. This system is a duplicate of the one formerly used at Texas A & M University except for the counter (Mathews et al, 1972)

The otoliths (ear stones) of fishes are commonly used to describe the age and growth of marine and freshwater fishes. These non-skeletal structures are fortuitous in their utility by being composed of mostly inorganic carbonate that is inert through the life of the fish. This conserved record functions like an environmental chronometer and bomb-produced radiocarbon (14C)—a 14C signal created by atmospheric testing of thermonuclear devices—can be used as a time-specific marker in validating fish age. However, complications from the hydrogeology of nearshore marine environments can complicate 14C levels, as was the case with gray snapper (Lutjanus griseus) along the Gulf of Mexico coast of Florida. Radiocarbon of these nearshore waters is influenced by freshwater input from the karst topography of the Upper Floridan Aquifer—estuarine waters that are 14C-depleted from surface and groundwater inputs. Some gray snapper likely recruited to this kind of environment where 14C levels were depleted in the earliest otolith growth, although age was validated for individuals that were not exposed to 14C-depleted waters to an age of at least 25 years with support for a 30-year lifespan.

The Aqueduct is one of the city landmarks of Skopje, Republic of North Macedonia. It was part of a water-supply system, with a total original length of about 10 km, while its surface remains are about 385 m long. The age of the Aqueduct is not known—several hypotheses place it to periods between the 6th and 16th centuries. Six mortar samples from different positions of the eastern façade were taken for radiocarbon (14C) dating. In order to extract only the carbon associated to the time of building, three strategies for sample preparation were used: (1) mechanical separation of lime lumps formed during mortar hardening (2) selection on the basis of particle size and the ability to suspend in water induced by ultrasonic shock, and (3) collection of two gas CO2 fractions produced from the same bulk in reaction with acid. Characterization of fractions was performed by isotopic carbon composition and FTIR-ATR analyses. The most plausible results were obtained from lime lump fractions that were dated in the timeframe of 15th to 17th century.

The peat bog at Homoródszentpál Kerek-tó (Round Lake), situated in Homoród Hills of the Eastern Carpathians in Romania, provides a continuous record of paleoclimatic and paleoenvironmental changes from the Early Holocene. In this study, we present a 7500-year-long high-resolution record of past climatic changes and signs of human impact recorded in a peat bog via integrating sedimentological, paleoecological and geochemical proxies. The basin of Round Lake formed around the Pleistocene–Holocene border when the permafrost thawed. Ponded water accumulated in the catchment basin from the beginning of the Holocene but ca. 7500 cal BP years ago lacustrine sedimentation was exchanged for peat accumulation. The 570-cm-long core was subsampled at 2–4 cm intervals and subjected to grain-size, loss-on-ignition (LOI), pollen, and radiocarbon (14C) analyses. Our findings were correlated with and interpreted in the light of paleobotanical records deriving from archaeological sites and the newest bioclimatological models of the nearby areas. Sedimentological analysis document erosion and accumulation events which were influenced by more complex processes like climate change. Based on environmental historical and climatic data we aimed to reconstruct the environmental changes of forested areas in the Homoródi Hills.

Northeastern North America has produced an incredible number of late Pleistocene faunal remains; however, many of these were discovered and excavated prior to the development of radiocarbon dating. Moreover, many of the 14C dates that do exist for such specimens were assayed prior to the development of purified collagen extraction methods, were performed on botanical remains of unspecified association with the faunal remains, or were accepted without concerns of young-carbon contamination from museum preservatives. Here, we present a set of high-precision accelerator mass spectrometry (AMS) dates obtained on Pleistocene faunal specimens from Connecticut, New Jersey, and Pennsylvania. Our data contain both newly discovered specimens and specimens that have resided in museum collections for over a century.

Lime (grouting) from old structures near city of Khar'khov [50° 00′ N Lat, 36° 10′ E Long]. Subm. [n.d.] by L. P. Papkova.

The following list sums up the results of radiocarbon dating of geologic samples obtained mostly during 1978 and 1979. Measurements have continued with the same proportional counters, pretreatment procedures, carbon dioxide purification, measurement and calculation as described previously (Pazdur et al, 1982). Ages are reported as conventional radiocarbon dates in years before ad 1950. No corrections for 13C/12C ratio were made for samples reported in this date list. Infinite dates are based on a 2-sigma criterion (Pazdur and Walanus, 1979). Sample descriptions and comments are based on information provided by the submitters.

This paper presents a set of accelerator mass spectrometry (AMS) radiocarbon dates obtained from various archaeological samples collected from 3 shellmounds—CA-MRN-114, CA-MRN-115, and CA-MRN-328—within China Camp State Park, Marin County, California, USA.

Vitória Bay is located in the south-central part of the State of Espírito Santo (SES). Multiproxy analyses were performed on samples from a 490-cm-long sediment core collected at the coordinates 40°18′23′′W and 20°14′48′′S. The objective of this study was to identify and integrate the multiproxy data to determine the environmental dynamics during the Holocene. The material was subsampled every 10 m and submitted to standard methodological processing. The sediment core was dated to two depths: the oldest age was between 9396 and 9520 cal yr BP at a 480-cm depth, and the youngest age was from 7423 to 7511 cal yr BP at a 304-cm depth. The integrated analysis revealed evidence of three major environmental changes in Vitória Bay. The first phase had a fluvial influence (depth of 490–480 cm; 9396–9520 cal yr BP). This was followed by a transitional period (depth of 480–290 cm; 7423–7511 cal yr BP) with a salt influence due to the Last Marine Transgression (LMT). Later, the environmental stability was similar to that of today (290 cm to the core top). This was a reflection of the Last Marine Regression (LMR) in the Holocene.

The following radiocarbon measurements are a partial list of projects and samples dated since January 1975. The technique used is described in R, v 16, pp 402-408 and R, v 18, pp 210-220. Dates are calculated using 14C half-life of 5568 yr and errors are reported as one-standard deviation.

Travertine deposits occur abundantly at past and present sites of waterfalls in the Arbuckle Mountains region of Oklahoma. This area (1600km2) consists of folded and faulted Prepaleozoic and Paleozoic rocks, with abundant outcrops of Paleozoic carbonate rocks. Samples of recently deposited and old travertine from the Turner Falls area were collected during a 1987 field trip and analyzed for 13C, 14C and 18O content. The aquatic chemistry of travertine depositing creeks was investigated systematically and compared with those of similar areas in SE and central Europe.

When ancient hearths at open archaeological sites do not yield carbonized annual plant remains or other high-quality samples, wood charcoal is commonly used for radiocarbon dating. Sagebrush (Artemisia tridentata Nutt.), a shrub frequently used for fuel across much of the western United States, seems a potentially better candidate for 14C dating than tree wood since the possibility for significant age discrepancy might be less. A comparison of multiple assays from single features reveals that sagebrush can overestimate age more than even tree wood charcoal. A plausible cause of this appears to be persistence of the shrub on the ground surface for an extended interval after death, such that use as fuel almost invariably occurs hundreds of years after fixation of carbon. The potential for age discrepancy may decrease as population density increases because the demand for fuel wood would have resulted in a more rapid turnover of the fuel biomass. This is not true for Archaic period foragers of western North America when population levels were likely quite low and residential mobility quite high.

A major collective effort was made to develop a data base for establishing the relationship between 14C and calendric ages (Stuiver, 1982). The early “cosmic schwung” fit between the two ages (Suess, 1970a, p 310) and the 10,350 yr period of the grand trend (Suess, 1970b, p 596) have recently been replaced by the period of 12,100 yr (Suess, 1980). The period of the grand trend was estimated by correlating the data with an a priori postulated sine function (Suess, 1970, p 596), or more recently a polynomial fit of the sixth degree was used (Klein et al, 1982). In the detrended data, periods (wiggles) of between 2400 yr and 104 yr were identified by conventional time series analysis. This approach could not be used to estimate the period of the grand trend, because the time series includes less than one cycle, whereas several cycles are required in order to get a meaningful result.

Radiocarbon measurements mainly on soil samples and soil organic matter fractions are being continued. Sample benzene preparation follows Scharpenseel & Pietig (1969; 1970a). Radioactivity is measured in single screw cap quartz vials using a Packard Tri-Carb 3075 as well as a Berthold Betaszint BF 5000.

The Chalk River Tandem Accelerator Mass Spectrometry System has reached a state of reliable measurement of 14C using 2 to 5mg elemental carbon prepared by Mg reduction of CO2. For two comparisons of a near-modern unknown with the NBS oxalic acid standard we obtain a total error of ∼±4.5%, consisting of a random system error of about ±3.5% combined with the statistical counting error. Measurements have been made on 70 samples in 30 days of running time during the past year. Samples included deep rock carbonates, cosmogenic 14C in meteorites, charcoal from earthquake fault zones, collagen of bone artifacts and fossil beetle-fragments.

Karst springs are abundant in Hungary, and many are thermal (temperatures >30°). As thermal springs are a significant part of Hungary's water resources, it is important to quantify their travel times in the karst systems. Thus, we chose to measure T and δ18O in the water and δ13C and 14C in dissolved inorganic carbon (DIC) in water from 50 thermal and nonthermal springs and wells in the Bükk Mountains, northeastern Hungary. Environmental isotope data confirm the karst water-flow pattern implied by earlier studies. We found the water in warm springs and boreholes to be mixtures of cold young and old thermal water. We also determined short mean-residence times for some large cold springs. The 14C activities measured in these springs indicate that the recharge area of the karst aquifer is open to the atmosphere, and atmospheric CO2 contributes to the 14C activity of these groundwaters. We observed good correlation between 14C and 3H activities and we determined negative correlations between 14C concentration and δ13C values and temperature. From the δ18O values of the oldest thermal waters, we attribute their origin to precipitation during colder temperatures than at present.