In comparison with windward coral reefs, the facies and evolution of leeward coral reefs has been discussed to a lesser extent. By accelerator mass spectrometry (AMS) carbon-14 dating of coral specimens collected from the trench excavated across a modern coral reef during a fishery port repair, we revealed the internal facies and Holocene evolution of a leeward reef in Ishigaki Island, Ryukyu Islands, southwest Japan. The reef facies can be split into three facies: the tabular Acropora framework facies, the tabular Acropora reworked facies, and the unconsolidated bioclast facies. The tabular Acropora reworked facies first formed a ridge by 3500 BR Then, the tabular Acropora framework facies grew both upward and seaward. The accumulation rates of the tabular Acropora framework facies ranged from 2.2 to 8.3 m/ka. Thus, the reef framework facies and accumulation rates of this leeward reef is similar to those of windward reefs, although the age of the reef top is younger than that of windward reefs.

Appropriate dating tools are essential for paleoenvironmental studies. Cosmogenic 32Si with a half-life of about 140 years is ideally suited to cover the dating range 30–1000 years. Here we have applied scintillation spectrometry for detection of natural 32Si to date marine shelf sediments. High detection efficiency, combined with stable background, allows for the detection of extremely low 32Si specific activities found in such sediments with counting rates below one count per hour. For a sediment core from the Ganges-Brahmaputra delta 32Si dating yields mean sedimentation rates of 0.7 ± 0.2 cm/yr for 50 to several hundred years BP and 3.1 ± 0.8 cm/yr for the past 50 years. The four-fold increase of the sedimentation rate over the past 50 years may reflect increased sediment loads in the rivers due to increasing human colonization within the rivers' drainage basins.

A geochronological survey of the Bengal shelf area involved results from more than 20 sediment cores dated using gamma spectrometry and the nuclides 137Cs, 228Ra, 226Ra, and 210Pb. In some cores, which contained older sediments, 32Si and 14C were determined to examine the possibility to extrapolate the obtained chronologies to century and millennial scale. Geochronological work in this region is faced with problems of cyclone-induced sediment reworking, grain-size effects on fallout nuclides, scarcity of carbonates, unknown 14C reservoir effect and sedimentation rates that are too high to obtain sediment cores long enough to establish a chronology. Despite these problems, comparison between the results of the different dating methods provided the most reliable sediment balance to date for the submarine delta of the Ganges-Brahmaputra river system and indicated that on a time scale of several centuries at least 35% of the annual sediment load is deposited.

In recent years, the most common technique for radiocarbon dating of deep-ocean sediments has been accelerator mass spectrometry (AMS) analysis of hand-picked planktonic foraminifera (forams). Some studies have exposed age offsets between different sediment size fractions from the same depth within a core and this has important implications when establishing a chronological framework for palaeoceanographic records associated with a particular sediment component. The mechanisms generating the age offsets are not fully understood, a problem compounded by the fact that the fraction defined as “large” varies between different studies. To explore this problem, we dated samples of hand-picked forams from two Biogeochemical Ocean Flux Study (BOFS) cores, for which the presence of an offset between the bulk carbonate and >150 μm foraminiferal calcite had already been demonstrated. The presence of a constant age offset between bulk carbonate and coarse fraction material at the two BOFS sites has been confirmed, but the magnitude of the offset is dependent on whether a simple size-separation technique or hand-picking of well-preserved forams is applied. This may be explained if the selection of well preserved forams biases the sample towards those specimens that have spent least time in the surface mixed layer (SML) or have undergone less size selective mixing. Modeling of the 14C profiles demonstrates that SML depth and sediment accumulation rates are the same for both the bulk and coarse sediment fractions, which is consistent with the hypothesis that size-selective mixing is responsible for the age offset.

Variability in surface and deep ocean circulation in the North Atlantic is inferred from grain-size characteristics and the composition of terrigenous sediments from a deep-sea core taken on Reykjanes Ridge, south of Iceland. End-member modeling of grain size data shows that deep-ocean circulation in this area decreased significantly during periods of maximum iceberg discharge. The episodes of reduced circulation correlate with the cold and abrupt warming phases of the Dansgaard-Oeschger cycles as recognized in the Greenland ice cores.

Compound-specific radiocarbon analysis of five fatty-acid biomarkers was conducted for marine sediments collected from the western North Pacific. The fatty acids (C12 to C34) showed a typical bimodal distribution pattern with two maxima at C16 and C26. Their carbon isotopic compositions ranged from −25.1‰ (C16) to −31.8‰ (C28), suggesting that they derived from terrestrial higher plants and marine organisms. A large variations of 14C ages were found among the fatty acids detected in the same sedimentary horizon of the core, ranging from 530 BP (C18) to 3250 BP (C28). The results of 14C analysis of fatty acids could be divided into two groups, i.e., lower molecular weight (LMW) fatty acids (C16, C18) derived from marine organisms and higher molecular weight (HMW) fatty acids (C24, C26, C28) derived from terrestrial higher plants. The HMW fatty acids showed older ages, ranging from 2550 BP (C24) to 3250 BP (C28), than LMW fatty acids (530 BP [C18] to 1,820 years BP [C16]). On the other hand, bulk-phase total organic matter (TOM) showed the age of 2260 BP that is between those two groups, suggesting that it was likely a mixture of organic matter derived from marine and terrestrial sources. The compound specific 14C ages and δ13C data of sedimentary fatty acids presented here could provide useful information to decipher the fate and transport process of terrestrial organic matter to marine sediments.

Radiocarbon dating was carried out in the sediment profiles of four marine sediment cores taken from Iskenderun Bay, Turkey. The bay is quite shallow in the present day, and a previous tectonic study had considered that the bay floor might have been subsiding. However, this cannot be so, for the 14C ages would thereby lead to the apparent paradox of normal marine sedimentation having taken place during times when glacio-eustatic sea level lowering would have exposed the bay floor. Rather, we conclude that the floor of Iskenderun Bay on the whole has been experiencing rapid uplift since the end of the Last Glacial, due to a combination of tectonic factors linked to the compression between the Anatolian and African plates.

A human skeleton recovered near Kennewick, Washington, USA in 1996 has been dated to the early Holocene on the basis of multiple radiocarbon determinations, an analysis of a style of a temporally diagnostic projectile point found embedded in the ilium of the skeleton, and geological investigations of the locality where the skeleton was recovered. Based on morphological criteria, the Kennewick skeleton, which is one of the most complete early Holocene human skeletons recovered so far in the Western Hemisphere, appears to be more similar to those of modern South Asians and Europeans than to modern Native Americans or to contemporary indigenous populations of Northeast Asia.

Advances in radiocarbon dating by accelerator mass spectrometry (AMS) have made it possible to date prehistoric cave paintings by sampling the pigment itself instead of relying on dates derived from miscellaneous prehistoric remains recovered in the vicinity of the paintings. The work at the Laboratoire des Sciences du Climat et de l'Environnement (LSCE) concentrated on prehistoric charcoal cave paintings from southern France and northern Spain. In most caves, pigment samples were collected from several paintings, and in some instances the sample size allowed for multiple independent measurements on the same figure, so that the coherence of the calculated dates could be tested. Before being dated, each specimen was subjected to a thermal treatment preceded by an acid and basic treatment of intensity commensurate with the sample size.

Nine bison drawings from three caves in the Cantabrian region of Spain—two from Covaciella, three from Altamira, and four from El Castillo—were sampled and dated. The 27 dates fell between 13,000 and 14,500 BP, allowing us to attribute the drawings to the Magdalenian period. The 24 dates for 13 drawings in the Cosquer cave indicated two distinct periods of painting activity—one around 28,000 BP and the other around 19,000 BP. The Chauvet cave paintings turned out to be the oldest recorded to date, as five dates fell between 32,000 and 31,000 BP. After discussing the sample preparation protocol in more detail, we will discuss the ages obtained and compare them with other chronological data.

The oldest traces of Velzeke go back to the Late Bronze Age and Early Iron Age, followed by a Gallo-Roman settlement and a later medieval village. Although the excavations document the history of the site in general, radiocarbon was used to clarify the successive phases within each feature. The results showed that the ditches at the Roman settlement and the neighboring temple area were already used during the Late Iron Age. The filling up of the ditches could be 14C correlated to a Gallo-Roman occupation phase. The oldest Christian cemetery at the site of the medieval church predates the construction of an important Carolingian stone building (9th to 10th centuries.). The stratigraphically lowest sediments of the ditches, surrounding the Carolingian church, are synchronous with the latest fill of the Iron Age ditch. According to historical and top-onymical sources the area of the Iron Age ditch becomes at that time part of a medieval agricultural field system.

The wetland site of Verrebroek “Dok” situated in northern Belgium is one of the largest and best dated locations of Mesolithic material in northwestern Europe. Salvage excavations organized since 1992 at this large, unstratified open-air settlement have revealed more than 50 spatially independent artifact concentrations with traces of numerous fireplaces. Single entity dating of charred hazelnut shells from surface-hearths and charcoal from hearth-pits was used to obtain information not only on the sites duration, but also on the relation between the surface hearths and the hearth-pits. The dates were also used to look at discrepancies between the radiocarbon chronology and the typo-chronology of the lithic artifacts.

This paper outlines a dating program designed to test the reproducibility of radiocarbon dates on different materials of Late-Glacial age (plant macrofossils, fossil beetle remains, and the “humic” and “humin” chemical fractions of limnic sediments) using a combination of radiometric (beta counting) and accelerator mass spectrometry (AMS) techniques. The results have implications for the design of sampling strategies and for the development of improved dating protocols, both of which are important if a high-precision 14C chronology for the Late-Glacial is to be achieved.

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.

The cave of Theopetra is located on the northeast side of a limestone rock formation, 3 km south of Kalambaka (21°40′46′′E, 39°40′51′′N), in Thessaly, central Greece. It is a unique prehistoric site for Greece, as the Middle and Upper Paleolithic, Mesolithic, and Neolithic periods are present here, bridging the Pleistocene with the Holocene. Several alternations of the climate during the Pleistocene are recognized in its stratigraphy. Among the most striking finds, two human skeletons, one from the Upper Paleolithic period after the Last Glacial Maximum and one from the Mesolithic period, should be emphasized, while in a deep Middle Paleolithic layer, the oldest human footprints, with remains of fire, were uncovered.

During the 13 years of excavation, evidence of human activity suitable for radiocarbon dating was collected, such as charcoal samples from hearths and bones from the two human skeletons. The use of proportional counters for the measurement of 14C in combination with the recent improvement of the calibration curve has enabled the production of high-precision reliable ages. Sixty 14C-dated samples, originating from 19 pits and from depths ranging from 0.10 m to 4.20 m, have already provided an absolute time framework for the use of the cave. The earliest limit of human presence probably exceeds 48,000 BP and the latest reaches World War II. Within these limits the 14C dating of samples from consecutive layers, in combination with the archaeological data, permits the resolution of successive anthropogenic and environmental events.

During the period between the IVth and IIIrd millennia BC, profound changes for the ancient populations inhabiting the northern region of Italy occurred. The first Indo-European migrations were altering the ethnographic characteristics and, with the production of the first copper artifacts, the Neolithic Age was drawing to an end. The most significant testimony of that dramatic period is unquestionably the Ötztal iceman. In addition, many other valuable archaeological sites, such as Alba (Cuneo, Italy), have been discovered. Although Alba produced the oldest evidence of copper objects in a Neolithic context (5380 ± 40 BP; GX-25859-AMS), more recent discoveries have underlined the importance of this archaeological site. In this paper we will report on a series of radiocarbon measurements of bone remnants which, combined with morphologic, stratigraphic, paleoanthropologic, and paleopathologic studies, have allowed us to gain new insights into the culture and chronology of the European Copper Age.

The Baden Culture is a widely spread culture of the Young Neolithics in east-central Europe. In southeast Europe, several parallel cultures are found at different places. The main innovations in east-central Europe associated with the Baden Culture were traditionally thought to originate in southeast Europe, Anatolia, and the Levant. However, in recent years, doubt about this theory has arisen among archaeologists.

Here, we try to contribute to this question by increasing the radiocarbon data set available for the Baden Culture. Thirty-two age determinations of samples from different sites assigned to the Baden Culture were performed by accelerator mass spectrometry (AMS) 14C dating. The new data were combined with previously published 14C dates. Data from the individual cultural phases of the entire Baden period and the parallel cultures in southeast Europe (Sitagroi, Cernavoda, and Ezero) were analyzed by sum calibration. Comparison of the results indicates that the southeastern cultures cannot be synchronized with the Boleráz period, the early phase of the Baden Culture. It seems that these cultures were parallel to the Baden Classical period. This finding, which has to be verified by more data from the southeastern cultures, contradicts the theory of the east-west spreading of these cultures.

Icon painting in the Ukraine is rooted in the Byzantine culture, after the conversion to the Christian religion. During the medieval epoch, Kiev became the artistic center for highly skilled icon painters. The icons were painted on wooden boards, specially made for this purpose. Historic dating of some even well-known icons is uncertain or not precise. Here we present for the first time radiocarbon dates for selected icons. Both liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS) dating methods were applied, allowing intercomparison.

This paper discusses the comparative chronology of Upper Paleolithic sites in the Middle Dnieper River basin, based on archaeological and radiocarbon evidence. Three chronological periods of the development of the Upper Paleolithic are distinguished in this area. According to the data obtained, the third period is similar to the European Magdalenian, yet its economies were different. The base of the subsistence economy for Dnieperian hunters was the procurement of mammoth, while reindeer was the most important for the subsistence of European Magdalenian. The abundance of mammoths and the raw material in the form of mammoth tusks made a deep impact on both the economy and material culture of the hunters in the Dnieper River basin. The 14C dates confirm the chronological subdivision.

The paper is compares the chronology of the monuments of the Scythian epoch located in the east and west of the Eurasian steppe zone on the basis of both archaeological and radiocarbon data. The lists of 14C dates for the monuments located in different parts of Eurasia are presented according to the periods of their existence. Generally, the 14C dates are confirmed the archaeological point of view and allow us to compare the chronological position of the European and Asian Scythian monuments on the united 14C time scale.

Tianma-Qucun is the biggest site of Western Zhou Dynasty discovered in Shanxi Province, China. It has been recognized as the early capital of Jin, a vassal state of Western Zhou. The territories were granted to the first Marquis of Jin with the title in the early days of Western Zhou. Bone sample series from the site were radiocarbon-dated by accelerator mass spectrometry (AMS) and calibrated with the Oxford calibration program OxCal 3.5. Bayesian analysis of the calibrated ages shows that the earliest residents of the Western Zhou came to Tianma-Qucun area in 1020–940 BC and the lower boundary of the Western Zhou is 796–754 BC, which corresponds well to the historical record 770 BC.