14C activity of dissolved inorganic carbon (DIC) in water and in recent tufa samples in several karst areas of Yugoslavia and Czechoslovakia was measured. Groundwater from 11 karst springs were measured for their isotopic content (14C, 3H, 13C), chemical composition (HCO3−, Ca2+, Mg2+) and physico-chemical properties (temperature, pH). Seasonal variations of the 14C activity of DIC in two karst springs in Plitvice Lakes area, Yugoslavia, were measured systematically from 1979 – 1987.14C activity of recent tufa samples from several locations downstream were also measured. The activity of DIC in karst spring water in both countries ranged from 63–87 pMC, which is attributed to differences in geologic structure of the recharge area, topsoil thickness and composition. Grouping of 14C activities of DIC ca (82±4)% is evident. Tritium activity at all the springs indicated short mean residence time (1–10 yr). Concentration of HCO3−, Ca2+ and Mg2+ in spring water varied with geomorphology. 14C activity of streamwater and recent tufa increased downstream from karst springs due to the exchange between atmospheric CO2 and DIC.

The object of our investigation was to study a mechanism of water formation in the Surdulica geothermal system (recharge area, age and homogeneity of the waters). We collected 56 samples to determine the chemical, stable isotope, 14C and tritium content of the waters. We found large stable isotope variations in precipitation collected at different altitudes, whereas the geothermal waters are largely homogeneous and seasonally independent. Data on springs and rivers, the local meteoric water line and recharge area were obtained. Three groups of groundwater were identified by age – modern from natural springs, old from mines and very old from the Vranjska Banja. Because the initial 14C activity of infiltrated waters from the recharge area is unknown, the age of thermal waters can only be inferred, from HCO3−, 14C and 3H content, to be 10,000 to 28,000 years old.

We have studied environmental isotopes and noble gases in groundwater samples from various locations in the Great Hungarian Plain along two selected hydrogeological cross-sections of ca 100km. The 14C groundwater ages were corrected hydrochemically and compared with age information derived from excess helium due to 4He from α-decay of U and Th and their daughter nuclides within the aquifer and to He accumulation from the crustal (and mantle) He flux. In correcting the 14C groundwater ages, we considered carbonate dissolution under open and closed system conditions in the infiltration areas. Non-radioactive reduction of the 14C/12C isotope ratio also plays an important role due to the addition of “dead” carbon species to groundwater along its subsurface pathway. High (corrected) 14C ages, which fall into the last global cold period, are supported by significantly lower heavy stable isotope values as well as lower temperatures derived from the noble gases Ne, Ar, Kr and Xe.

Groundwater of the Jakarta Basin aquifer is heavily exploited for drinking water. As a result, the piezometric head has dropped dramatically. Extensive hydrogeologic and numeric model studies have been made to find a reliable basis for managing available groundwater resources. Environmental carbon (14C, 13C) and other isotope analyses (18O, 2H, 3H) were made. Two sampling strategies were employed, which show that using well-defined and representative sampling sites, no matter how few, is the only way to obtain reliable geoscientific information. Large quantities of data from randomly distributed samples of uncertain origin is not recommended.

Measurements of 14C activity as well as determinations of the stable isotope composition (18O, 2H and 13C) of groundwater samples were made to investigate the flow path, origin, recharge and age of the Botucatu Aquifer System in Brazil, between 1984 and 1987. The stable oxygen isotope composition reflects infiltration during several climatic recharge conditions. Measured 14C activities range from 0.4 to 94.2% modern. δ13C values enable us to distinguish two groundwater types of different origins. There is a gradual increase of 14C ages from the outcrop area towards the central part of the basin, associated with a progression of the confining conditions. Anomalous fluoride contents seem to be correlated with high 14C ages of the groundwater. The reliability of the 14C data is discussed.

Extensive investigations of isotope content and hydrochemical parameters in soil gas, soil material, groundwater and seepage water from a Quaternary aquifer show a good correlation between 14C concentration of the groundwater and its mean residence time in the unsaturated zone. The initial 14C concentration varies between 100 and 50% modern. It decreases through solution and dissolution of carbonates to 50% of the 14C concentration of atmospheric CO2.

A sequence of annually laminated sediments of the Gościαz Lake spans ca 13,000 yr and is actually the longest known continuous sequence in the world. 14C age measurements were performed on organic and carbonate fractions of bulk samples of laminated sediments from core GO. Accurate measurements of varve thickness performed on the lower part of cores G1 and G2 were used to establish a floating varve chronology covering ca 10,000 yr. Matching of cores GO, G1 and G2 permits comparison of 14C dates with varve chronology. Good agreement of calibrated 14C dates with the varve time scale suggests annual lamination of the sediment. Analysis of periodicities in varve thickness indicates solar 11-and 22-yr cycles, as well as a 200-yr cycle over a good part of the investigated sequence. Results of 14C measurements of carbonate fractions are used to study changes in the water depth of the lake during its history.

Kau Bay Halmahera, Indonesia is a small marine basin that is separated from the adjacent SW Pacific Ocean by a shallow sill, 40m deep. Radiocarbon dating on piston cores in combination with a study on microfossils demonstrate that Kau Bay was a freshwater lake in Weichselian times. At 10,000 BP, the Bay became reconnected with the open ocean. It sill depth did not change in the intervening years, sea level at 10,000 BP stood 40m below the present level.

This study was carried out to determine time controls of erosion and sedimentation in the catchment area and lakes of the Naini Tal district in the Kumaon Himalayas. We present here our preliminary data from five lakes, Beon Tal, Garud Tal, Sukha Tal, Bhim Tal and Kamal Tal (Naukuchia Tal). A number of 14C dates are now available to estimate the sedimentation rate of the five lakes and magnetic susceptibility (xL; xfd) variation to determine the signature of sediment source. High xfd values indicate a higher proportion of soil component generally characterized by a slower rate of deposition, and low xfd values with a higher rate of sedimentation indicate rock-debris-derived sediment. A 14C chronology enables us to estimate the mean sedimentation rate whereas rock magnetic properties help us to characterize the type of source responsible for sedimentation.

An account is presented of the current status of the project to radiocarbon date the cloth of the shroud of Turin. The procedures dictated by the Turin ecclesiastical authorities to accomplish this are discussed. It will be concluded that the original protocol, as agreed to by all parties at the Turin Workshop in 1986, suggested a preferable procedure. However, if the three laboratories, who accepted the task of dating the shroud, obtain the same age for the shroud and the three control samples within a standard deviation or two completely independently, most knowledgeable scientists will probably accept the results.

An important Etruscan linen “book,” the Liber linteus Zagrabiensis, was preserved in wrappings of an Egyptian mummy. Stylistic estimates for the date of composition of the text vary. Three possible centuries were suggested, the 3rd and the 1st centuries BC and the 1st century ad. Radiometric and AMS dating of the linen book and the mummy has demonstrated multiple uses for differing aged materials. There seem to be at least two sets of linen wrappings of markedly contrasting ages, while separate fractions of the embalming unguent seemed to contain carbon of differing dates. 14C results suggest the most probable age range for the linen book is ca 360–210 cal BC, making the 3rd century BC stylistic date the most likely time of inscription.

Recent progress in high-precision calibrations of radiocarbon dates has led to evaluations of earlier research. This has been the case with dates from the Norse settlement at L'Anse aux Meadows which was discovered by Helge Ingstad in 1960. The most problematic feature of this series up to now was the use of sample material which partly derived from driftwood. The present paper concludes that charcoal from this site demonstrated no greater errors than normal from other settlement sites. With an assumed total systematic error of 30 ± 20 years, as a mean for various tree rings, the calibrated age range of L'Anse aux Meadows is AD 975–1020. This agrees well with the assumed historical age of ca AD 1000, a result which has also been recently corroborated by high-precision accelerator dating at the University of Toronto.

During an excavation of 1986 and 1987, a joint team from Utrecht, Siena and the Soprintendenza di Sassari e Nuoro, found a pre-Neolithic lithic industry in Corbeddu Cave, Oliena, Sardinia, which was dated to 8000–17,000 bp. The artifact typology is different from that of the mainland of the same period. The lithic and bone artifacts suggest an endemic isolated economy of the Upper Pleistocene in Sardinia.

Direct dating by simultaneous independent physical methods is of particular interest to prehistoric archaeology in central Europe. Radiocarbon and thermoluminescence measurements were made to date two tell settlements in the Carpathian Basin: the Late Neolithic site at Gorzsa (southeast Hungary) and the Eneolithic site of Vučedol (east Croatia, Yugoslavia). Samples from Gorzsa span from the Szakalhát to the Proto-Tiszapolgár periods, while most important cultural layers from the Vučedol site belong to the Baden, Kostolac, and Vučedol cultures. By including some of our earlier dates from the Tiszapolgár-Basatanya Copper Age site, a chronological framework, spanning the period from Late Neolithic to Early Bronze Age can be established. The quartz inclusion technique was used for TL dating of pottery. Beta and gamma dose rates were determined by TL dosimetry. Allowances were made for supralinearity, water content, and beta attenuation in quartz grains. The TL ages range from 1900 to 4300 BC and 3600 to 2900 BC, for the Gorzsa and Vučedol sites, respectively.

Radiocarbon dates of the Vučedol culture range from its earliest beginnings at Vučedol and Pivnica to its late phase at Vinkovci, Eastern Slavonia, Hrustovača, northwest Bosnia, Parte, Slovenia and Rudine, northwest Croatia. Recent 14C analyses are discussed and compared to corresponding dates outside the scope of the Vučedol culture. Findings provide evidence for the expansion of the late Vučedol culture both in time and space.

A large number of early boats discovered in the waterways of England are presently displayed in museums and as public monuments. In some cases conservation practices have caused problems in the radiocarbon dating of these otherwise undated artifacts. Specimen pretreatments are described and the chronology of the boats in different regions of England are presented with approximate calibration to calendar date ranges.

Progress in radiocarbon dating and calibration accuracy should lead to the development of a calibrated radiocarbon chronology of Near Eastern archaeology, particulary for historical times. The lack of such an independent and impartial chronology is a major constraint, not only in archaeological studies, but also for interdisciplinary research involving the history of man, landscape and climate in the Near East and adjacent regions.

Unlike wood charcoal, as found admixed to other cultural remains, ostrich eggshells can be of more direct significance in 14C dating, especially if they were processed to form, eg, eggshell beads. Normally the time span between laying the egg and working the shell beads is short enough to be negligible for 14C dating purposes. Another advantage of eggshell dating is that the carbonate of the shell seems to keep exceptionally well over the millennia, whereas, especially in surface sites in a desert environment, organic material such as wood, charcoal or bone protein tends to decompose. With few comparative test samples, we thought ostrich egg samples would yield 14C dates somewhat too young. The deviation is, however, balanced by performing 13C analyses and a correction for isotope fractionation of ca 350yr.

The Tehuacán region in Central Mexico is thought to be the locale of origin of Zea mays, or maize, a cultivated plant pivotal in the development of agriculture in the Americas (MacNeish, 1981, 1985). The age of the earliest maize, and its rate of dispersal are thus important components of cultural development in the New World. We have secured permission from the Federal Government of Mexico to date critical specimens from Tehuacán, which represent what are probably some of the earliest known stages of maize evolution. Twelve Zea mays samples have been dated, six from Cueva San Marcos and six from Cueva Coxcatlán. These were selected as having the best stratigraphic control and correlation with previously dated charcoal samples, and to represent the most ancient maize. Corn from Cueva San Marcos is oldest: four of the six specimens from this cave were within statistics of 4700 BP (uncalibrated). The oldest known domesticated corn is thus no older than 3600 cal BC (dendro-calibrated in calendric years).

Several approaches to dealing with the problem of mixed-age fossil assemblages are presented. These involve the use of amino-acid epimerization analysis (D-alloisoleucine/L-isoleucine ratio, or A/I) and are illustrated by deposits of land snail shells. This method requires only very small samples, so shells can be analyzed individually. Mixed-age deposits are indicated when variation in A/I among individual shells within the deposit exceeds the analytical error. Methods are presented for 1) estimating the true time of deposition of slightly-mixed-age assemblages based on bulk 14C dates and epimer analyses, 2) selection (for 14C analysis) of a set of individual shells that are uniform in age and represent the true time of deposition, and 3) estimating ages of individual shells within a mixed-age deposit based on their A/I ratios.