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.     

THE SUBTRACTION TECHNIQUE OF THERMOLUMINESCENT DATING

Combination of the routine approaches of thermoluminescence dating, the fine-grain and inclusion methods, allows an age to be determined that is independent of knowledge of the environmental dose-rate. This socalled subtraction technique is exampled by several terracottas of museum origin and some pottery collected from archaeological contexts without associated burial media. Age determination is estimated to have an accuracy of around ± 12%, in favourable conditions.     

THERMOLUMINESCENT AUTHENTICITY STUDY AND DATING OF RENAISSANCE TERRACOTTAS

A comparative study is made of the thermoluminescence (TL) of terracottas of the Renaissance era and some known limitations of such ware dating to the middle of the last century. The data shows that conclusions on authenticity of an unknown work can be reliably obtained using this scientific method. Also examples are presented of accurate dating of genuine terracottas despite a lack of knowledge about the environmental circumstances of each piece's archaeological past.     

THERMOLUMINESCENT DATING: ASSESSMENT OF ALPHA PARTICLE CONTRIBUTION

A new system for specifying alpha source strength, in terms of track length per unit volume of sample, is proposed. It is based on the experimental observation that the TL induced per unit length of track is essentially independent of alpha particle energy. The new system avoids the need to make assumptions about sampple stopping power and it is shown to be consonant with the old system as long as up-to-date evaluation of alpha ranges is used. A revised table of dose-rate data is given.     

RADIOCARBON DATING: REVOLUTIONS IN UNDERSTANDING*

Radiocarbon dating has undergone a number of ‘revolutions’ in the past 50 years. This is in part because it is a field in continuous development, but perhaps more because of its profound impact on archaeology and the nature of interdisciplinary research. In order to understand the use of radiocarbon as a dating tool, it is necessary to understand the life cycle of radiocarbon, from its production in the upper atmosphere, through its sequestration in reservoirs and samples and its final decay. Different elements in this life cycle lead to complications, or subtleties that need to be understood if we wish to develop high‐resolution chronologies. Most of the changes that have influenced radiocarbon dating are revolutions in understanding of the natural world in disparate academic disciplines. More than ever, it is necessary for users of radiocarbon to understand and engage with the science that underlies the method.     

THE ASSESSMENT OF ERROR LIMITS IN THERMOLUMINESCENT DATING

This paper discusses known sources of error, both random and systematic; suggests quantitative limits; and proposes a consistent method for compounding them to yield an overall error in age, both for individual sherds and for the weighted average of a number of sherds from the same context. It is proposed that two error limits should be quoted for the date of a context: first, the standard error of the mean value as calculated from the experimentally observed root-mean-square deviation of the individual samples, and secondly, the expected overall error from the sources discussed in the paper. The former can be considered as a lower limit and relevant when comparing contexts on the same or similar sites whereas the latter is more realistic when comparing TL dates with radiocarbon or archaeologic chronology.     

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.     

THERMOLUMINESCENT DATING OF COLOMBIAN POTTERY IN THE YOTOCO STYLE

Two contexts from the Colombian sites, Yotoco Ferry and Moralba, had been linked by archaeological similarities in pottery style, and dated by association with ware from other sites at circaa.d. 1000. However, radiocarbon dating of those contexts set Moralba at circa 800 b.c. , some 2000 yr older than Yotoco Ferry. Thermoluminescent dating of pottery from Yotoco Ferry dated it at circaa.d. 900, and pottery from Moralba was dated at circaa.d. 870. In addition a metal-smelting pottery crucible, thought to be prehispanic, was studied by thermoluminescence and dated, on the contrary, at less than 120 yr old.     

THERMOLUMINESCENT DATING OF FIRED ROCK-CRYSTAL FROM BELLAN BANDI PALASSA,CEYLON

Fired rock-crystal was found within the matrix of a Balangodese (pre-Vedda) burial in a Mesolithic midden in Ceylon; thermoluminescent measurements indicated a date of about 7000 years before present.     

THERMOLUMINESCENT DATING OF EGYPTIAN PREDYNASTIC POTTERY FROM HEMAMIEH AND QURNA-TARIF

Eight sherds from Hemamieh and two from Qurna-Tarif, both Predynastic settlement sites in the Nile valley, have been dated by the thermoluminescence method (quartz inclusion technique). The results put the Badarian phase at Hemamieh in the sixth and fifth millenium b.c. , and the Gerzean phase in the first half of the fourth millenium b.c. The dates for the village of Qurna-Tarif fall around 4000 b.c.