BRISTLECONE PINE AND ANCIENT EGYPT: A RE-APPRAISAL

Previous comparisons of the radiocarbon dates of tree-ring-dated bristlecone pine samples and historicallydated samples from Egyptian archaeological sites have led to conflicting conclusions regarding the validity of the bristlecone pine calibration of radiocarbon dates. However, the new statistical analysis presented in this paper shows that the bristlecone pine calibration of the radiocarbon time-scale is not incompatible with the given Egyptian historical chronology in the period 3000–300 B.C. (calendar years). This analysis is the first to allow for possible additional variability in the radiocarbon dates of short-lived samples (due to short-term fluctuations in the atmospheric carbon-14 level), and to examine the effect on the analysis of any changes in the precision ascribed to the historical dates of the samples. Furthermore, the paper examines the reasons for the conflicting conclusions obtained in previous analyses, and uses the differences in the paired radiocarbon dates on the Egyptian samples to investigate the overall repeatability of these radiocarbon measurements.     

Radiocarbon Dating and the Historical Archaeology of Korea: An Alternative Interpretation of Hongryeonbong Fortress II in the Three Kingdoms Period,Central Korea

Relying heavily upon historical records to build archaeological chronologies, many Korean historical archaeologists question the utility of radiocarbon dating. To challenge this tendency, we test a model based on historical records by analyzing radiocarbon dates. We dated two bulk samples from Hongryeonbong Fortress II, Seoul, South Korea, which is known historically to have been occupied between a.d. 500 and 551. By dividing bulk samples into smaller aliquots, we dated 40 subsamples and statistically estimated consensus dates. The consensus dates do not support expectations of the historical model, as they do not lie within the temporal range provided by historical records. We propose an alternative model that explains both the radiocarbon dates and the historical records. It is suggested that radiocarbon dating can be successfully applied to the reconstruction of historical periods and is a way of mitigating possible biases of models based solely on historical records.     

RADIOCARBON DATING OF MORTARS FROM ANCIENT GREEK PALACES

This study deals with radiocarbon dating of lime mortars which were used as supports for Mycenaean and Minoan paintings. The ¹⁴C dates are. on the whole, compatible with the historical data. and thus show that a large proportion of the Mycenaean surficial coatings can be dated by the radiocarbon method. However. in order to determine the age of the mortars accurately. it is necessary to evaluate the amount of sedimentary carbonate which may have been added to them. It is shown here that the oxygen and carbon isotope compositions of lime mortars are significant indicators that such a mixing actually took place.     

DATING ANCIENT LIME MORTARS BY GEOCHEMICAL AND MINERALOGICAL ANALYSIS

This paper proposes a method of dating based on the study of the mineralogy and geochemistry of lime mortars. If the mortars used in constructing the various parts of a building are made from limestones of distinct geochemistry (minor elements) and mineralogy (clay content), such differences should be identifiable in their compositions. Furthermore, if some parts of the building can be reliably dated, the mortars used in their construction can be compared with mortars taken from parts of the building whose dates are unknown. Under certain conditions, a relationship can be established between the mortars, and a date may be proposed. An experimental procedure, based on identification of mortar phases, is proposed. The method was tested on two historical monuments, built in the eleventh to twelfth and nineteenth centuries respectively, which illustrate different dating problems.     

Investigating the likelihood of a reservoir offset in the radiocarbon record for ancient Egypt

Some radiocarbon dates for ancient Egypt have been significantly offset from the established historical chronology (see Bonani et al., 2001). In this paper, short-lived plant species collected in Egypt between 1700 and 1900 AD were used to investigate the possibility that the radiocarbon record had been influenced by reservoir effects. AMS radiocarbon measurements were made on 66 known-age samples, resulting in an average offset from expected values of 19 years. The implications of this minor discrepancy on the likelihood of a reservoir process are discussed, and the agreement of the data with recent models of radiocarbon seasonality is also considered.     

Comments on relations West Norway ‐ Western Europe documented in petroglyphs

Dendrochronologic calibration of radiocarbon dates, which is of vital importance when such dates are compared with historical records, is discussed.

The nature and causes of variations in the past atmospheric radiocarbon content are briefly described. Different calibration curves are compared with available high‐precision data on radiocarbon in tree rings, and also with preliminary results from the joint efforts of U.S. scientists to establish an optimal calibration scheme.     

Cretaceous aggregate and reservoir effect in dating of binding materials

Lime mortars may contain carbon from different origins. If the mortars are made of totally burnt lime, radiocarbon dating yields the true age of building construction. The presence of carbonaceous aggregates gives the so-called dead carbon effect, which may generate older ages. Another source of carbon is charcoal present in mortars. An attempt has been made to apply the radiocarbon method to mortars of archaeologically estimated age from the Dead Sea region. Petrographical analyses of these samples show the carbonaceous character of the binder and large amounts of limestone aggregate. Determination of the mineral composition of the mortars and comparison with the geology of the surrounding, allows the provenance of the raw materials to be identified. They probably represent the Cretaceous rocks of the Judea Group. Separate radiocarbon dates were made on bulk mortar samples, binder, charcoal fragments and separated fractions from mortars. In the case of binder-aggregate mixture the reservoir effect correction has been applied.     

EFFECTS OF MILLING: A POSSIBLE FACTOR INFLUENCING THE DURABILITY OF HISTORICAL MORTARS

In their literary texts, some classical Roman authors such as Gaius Plinius Secundus and Marcus Vitruvius Pollio stress the importance of milling when preparing mortars. Following these indications, this work describes the effects of milling between lime (calcium hydroxide) and clay brick powder before and after the addition of water. Starting and resulting materials were investigated by XRPD, SEM/EDS, differential scanning calorimetry and thermogravimetry (DSC/TC), colorimetry, densimetry and porosimetry. Prolonged milling changes the mineralogy of the starting materials and increases their reactivity. The final lime pastes, starting from materials milled for varying periods of time, had different mineralogical and physical characteristics. These results may help to clarify the reasons for the marked differences in durability of some historical mortars.     

Radiocarbon Dating of Architectural Mortar: A Case Study in the Maya Region,Quintana Roo,Mexico

Abstract

The use of radiocarbon dating to analyze mortar and charcoal inclusions within mortar or plaster is a useful way to date the construction of architecture, particularly when options for other chronometric methods are limited. In the Yalahau region of northern Quintana Roo, Mexico, members of the Yalahau Regional Human Ecology Project have faced challenges in dating buildings made of large blocks of stone in the Megalithic architectural style. The Megalithic style poses serious problems for any analysis, as excavating into structures with stones weighing several tons can be dangerous, expensive, and time consuming. Additionally, there are no associated sculptures, texts with dates, or other traditionally accessible chronological markers. These factors have resulted in a reliance on a ceramic chronology despite the uncertainty of the dating of many ceramic types in this region, as well as the questionable contextual associations between recovered ceramics and architectural construction phases. Megalithic-style structures at the ancient Maya site of El Naranjal have residual mortar with charcoal inclusions left behind during the mortar-making processes that can be extracted and dated with AMS ¹⁴C methods. Several samples of mortar and charcoal were obtained from structures 1 and 10 from exposed exterior walls and an interior vault. The resulting dates confirm the date for the construction based on ceramics excavated from the same site.     

Interpreting,dating, and reevaluating the botanical assemblage from tell Kedesh: a case study of historical contamination

Botanical assemblage including charred and mineralized macro plant remains were examined from tell Kedesh in the Upper Galilee, Israel. Flotation samples were collected from various contexts within and outside a large Persian-Hellenistic administrative building complex at tell Kedesh, dated to the 5th to the 2nd century BC, based on the archaeological material. Four AMS radiocarbon dates were obtained on plant macro remains recovered from the flotation samples from the complex. The radiocarbon dates range from the 9th century BC to 17th century AD. The discrepancy among the radiocarbon dates obtained from plant remains and those based on archaeological material can be attributed to bioturbation, including the deep burrowing of harvester ants. The study demonstrates the need for direct radiocarbon dating of the charred plant remains generally assumed to be of ancient origin. This research improves the understanding of depositional and postdepositional processes of plant macro remains and explains their mode of arrival, relevant for the sites with a long occupational history by humans and animals.     

RADIOCARBON DATING OF KILL SITES

Age determinations of kill sites, where charcoal is generally absent, has usually depended on radiocarbon analyses of bone material. However, it has been seen with known-age samples that these dates are often in error due to contamination by plant products or ground water carbonates. The use of soil samples from strata both above and below, as well as the level containing the artifacts, offers important advantages. The soil profiles present sequences of dates, whereas the bones are only individual samples. The distribution of the soil date values can indicate upper and lower limits for the age of the kill site. The Taima-taima paleo-indian site in the state of Falcón, Venezuela is presented as an illustration of the application of radiocarbon dating of soil to archaeological problems. A total of 22 samples were processed. It is seen that soils from two profiles indicate a dating of 13 000 years for the kill. Taking into account reasonable extents of error, uncertainties of ± 2000 years can be estimated. The non-carbonate fraction dates are in agreement with the earth samples, but this is probably due to the organic matter extracted from these materials being mostly soil contamination in the porous bone matrix. Fluorine measurements on the bones confirm the Pleistocene origin.     

FRESCO AND LIME‐PAINT: AN EXPERIMENTAL STUDY AND OBJECTIVE CRITERIA FOR DISTINGUISHING BETWEEN THESE PAINTING TECHNIQUES

Identification of the painting technique adopted by an artist is often debated in studies on the characterization, restoration and conservation of mural paintings. However, objective criteria to identify the two main lime‐based painting techniques, fresco and lime‐paint, have not yet been systematically verified on replicas. Replicas were painted following both fresco and lime‐painting techniques. A comparison of microstratigraphic sequences and distribution of chemical elements reveals systematic differences between the two techniques, providing objective distinguishing criteria. Samples from the Abbey of Chiaravalle (Milan, Italy) and Pompeii were also analysed, and the results were compared with experimental data to validate the recommended criteria.     

Chemical and Microscopic Study of Masonry Mortar in Ancient Pagodas in East China

Ancient mortars played a crucial role in the construction of historical architectures due to their physical and chemical compatibility with traditional building materials such as stones and bricks. Therefore, the analysis and optimization of the ancient mortar formula are significant in the restoration and preservation of historical sites. In this work, 20 mortar samples selected from five ancient stone pagodas in Zhejiang Province, China, were analyzed. The results showed that mud, lime-soil mortar, lime-sand mortar, and lime-gypsum mortar were used as binders in these pagodas. The Ca(OH)₂/aggregate ratio ranging from 0.3 to 2.7 was usually used to prepare lime mortar. Protein and polysaccharide were also found in some samples.     

Radiocarbon dates for the late Middle Palaeolithic at Pech de l'Azé IV,France

This paper reports a series of radiocarbon dates on bone samples coming from the Mousterian of Acheulian Tradition (MTA) Layer 3 at the top of the Pech de l'Azé IV (Pech IV, France) Middle Palaeolithic sequence. All of these samples showed evidence of human impact, and they were prepared using current pre-treatment techniques to remove or identify contamination. The results indicate that the MTA at Pech IV started prior to the current limit of radiocarbon calibration (circa 50 ka BP) and ended by 45 ka cal. BP. These dates are supported by additional TL and ESR dates from the sequence, confirm previously suggested correlations between Pech I and IV, and generally fit within the known age range for the MTA. The oldest dates reported here may also lend support to still older TL dates for the MTA that taken together suggest that the MTA extended from late MIS 4 or early OIS 3 through to the end of the Middle Palaeolithic in southwest France.     

Technology,chronology and the role of crucible steel as inferred from iron objects of the ancient site at Junnar,India

Ordinary iron objects from an ancient habitation site at Junnar in India, dating to the 2nd BC to AD 2nd century, were examined for their microstructure, chemical composition and age. The objects were mostly made of high carbon steel with a homogeneous microstructure consisting of fine spherical particles of carbide in the ferrite background, free of non-metallic inclusions. Their carbon concentration ranged from 0.7% to over 1.6% with one exception at 0.2%. Some of them contained trace amounts of silicon, manganese and sulfur while one object retained cavities due to volume contraction during solidification reactions. These features indicate that the objects examined constitute an early example of Indian steel making in crucibles. Evidence was found that basic techniques needed for the success of crucible steel technology were mostly available at Junnar at the time. The radiocarbon measurement on carbon samples extracted from one of the iron objects placed its date between 176 BC and AD 20, in agreement with the radiocarbon dates of three charcoal samples from the same site. The forgoing results support that crucible steel was produced in India at a much earlier date than previously supposed, to serve as a material for specific needs arising in daily life.     

Methods for the Study of Ancient Hair: Radiocarbon Dates and Gene Sequences from Individual Hairs

Genetic data from archaeological specimens provides a potent new approach for addressing questions in prehistory. Hair from archaeological sites is an important but overlooked data source amenable to molecular analysis. To date DNA identification from hair is limited to modern samples. Our study is the first to report DNA recovery from a 9800-year-old specimen. We report methods used to extract mitochondrial DNA and obtain accelerator mass spectrometry radiocarbon dates (AMS-¹⁴C) from hairs plucked from a piece of ancient bighorn sheep (Ovis canadensis nelsoni) skin found at Smith Creek Cave, Nevada. The ability to obtain reliable radiocarbon dates and DNA sequences from single ancient hairs opens new possibilities for addressing biological questions in prehistory.     

RADIOCARBON DATING OF MESOLITHIC OPEN‐AIR SITES IN THE COVERSAND AREA OF THE NORTH‐WEST EUROPEAN PLAIN: PROBLEMS AND PROSPECTS

This paper discusses the problems with sampling materials and sampled contexts in the framework of radiocarbon dating of Mesolithic sites situated in generally dry, acid and bioturbated coversand deposits within north‐western Europe. The case studies presented all relate to the coversand regions of northern Belgium and the Netherlands, two areas for which very large sets of radiocarbon dates performed on different organic components are currently available. The study points out that charred hazelnut shells from surface hearths and charcoal from hearth pits guarantee the most secure dating results, while the dating of calcined bones and food crusts from Final Mesolithic pottery so far remains problematic.     

Fluvial sediments, correlations and palaeoenvironmental reconstruction: The development of robust radiocarbon chronologies

Multiple sequences of radiocarbon dates extracted from organic materials are increasingly being used to provide robust chronologies for landscape development, particularly the timing and correlation of significant climatic and ‘process’ events. Whilst the validity of using such frameworks in sedimentary environments such as lake basins and raised bogs has been the focus of much attention, such debates have not extended to fluvial systems. Using examples from three lowland, vertically accreting river valleys in East Anglia, UK, this paper assesses the robustness of their associated radiocarbon chronologies by assessing the contrasting age estimates that are obtained by dating different parts of the same organic sample (humic, humin and plant macrofossils) at a variety of stratigraphic levels. Overall, the humin and humic acid fraction results were statistically consistent, whilst the plant macrofossil remains were found to be of a slightly younger age. In these examples, it is argued that the younger ages appear to be the result of Phragmites (common reed) roots pushing plant macrossils through the sedimentary sequence or opening up voids for material to fall through, although studies in lacustrine and mire environments suggest alternative explanations may also be possible. Whichever explanation is preferred, this study demonstrates clearly that the complexity of valley floor stratigraphy and processes is such, that using single radiocarbon dates, whether AMS or bulk samples to reconstruct chronologies of ‘geomorphic system response’ may need to be refined and subjected to the same level of assessment that has been applied in other sedimentary systems.