The archaeology of radiocarbon accelerator dating

Accelerator mass spectrometry (AMS) allows radiocarbon dating to be carried out by direct counting of¹⁴C atoms, rather than the conventional counting of radioactive disintegrations. The result is that samples up to 1000 times smaller can be handled. The approach was tested in principle by 1977 and for archaeological operation by 1983. More than 2000 samples per year are now being dated worldwide. The machines can now operate to about ± 80 years or better. Dates older than 40,000 years have not yet been achieved, but the ability to use small samples has already had considerable impact on dating the period 10,000–30,000 years ago. Bone is an ideal material for the new technique, since amino acids can normally be isolated and purified from gram-size samples. Studies of the origins of domestication are aided by the dating of individual grains and seeds. Because small samples can be mobile in the soil, careful sample selection strategies and procedures are required. The full impact of the technique can be assessed only through the rapid and comprehensive publication of archaeological results.     

Exponentially decreasing tooth growth rate in horse teeth: implications for isotopic analyses

A range of archaeological and palaeoclimatic studies use isotopic analyses of ungulate hypsodont tooth enamel. Such studies commonly assume a constant growth rate, though this has not been fully tested. Here, we use stable isotope analyses of sequential enamel samples to study horse tooth growth. We fit the data using models corresponding to constant and exponentially decreasing rates of growth, and compare the results to metrical data showing the geometry and timing of apposition. The results indicate enamel apposition and maturation advances at an exponentially decreasing rate. An understanding of this variable growth rate is crucial for interpreting isotopic data from equid teeth.     

Real‐time quadrupole mass spectrometer analysis of gas in borehole fluid samples acquired using the U‐tube sampling methodology

Sampling of fluids in deep boreholes is challenging because of the necessity of minimizing external contamination and maintaining sample integrity during recovery. The U‐tube sampling methodology was developed to collect large volume, multiphase samples at in situ pressures. As a permanent or semi‐permanent installation, the U‐tube can be used for rapidly acquiring multiple samples or it may be installed for long‐term monitoring applications. The U‐tube was first deployed in Liberty County, TX to monitor crosswell CO₂ injection as part of the Frio CO₂ sequestration experiment. Analysis of gases (dissolved or separate phase) was performed in the field using a quadrupole mass spectrometer, which served as the basis for determining the arrival of the CO₂ plume. The presence of oxygen and argon in elevated concentrations, along with reduced methane concentration, indicates sample alteration caused by the introduction of surface fluids during borehole completion. Despite producing the well to eliminate non‐native fluids, measurements demonstrate that contamination persists until the immiscible CO₂ injection swept formation fluid into the observation wellbore.     

An investigation of soil phosphorus distribution within occupation deposits from a Romano-British hut group

A simple scheme for soil sampling and subsequent analysis for total soil phosphorus using perchloric acid digestion is described and its application illustrated by samples from the native farmstead of the Roman period at Cefn Graeanog in North Wales. The floor deposits of three distinctive buildings were analysed, and the data obtained enhanced by Trend Surface Analysis to produce generalized maps of the phosphorus distribution, together with levels of significance of such distribution patterns. These were then used to clarify the details of the interpretation of the usage of the various types of building. Data for soil phosphorus concentration clearly reveal the pattern of erosion of constructed floors, the presence of features such as hearths and drains, and can be used to reveal patterns not otherwise discernible by excavation techniques.     

Cultural dynamics and ceramic resource use at Late Bronze Age/Early Iron Age Troy,northwestern Turkey

Changes in resource use over time can provide insight into technological choice and the extent of long-term stability in cultural practices. In this paper we re-evaluate the evidence for a marked demographic shift at the inception of the Early Iron Age at Troy by applying a robust macroscale analysis of changing ceramic resource use over the Late Bronze and Iron Age. We use a combination of new and legacy analytical datasets (NAA and XRF), from excavated ceramics, to evaluate the potential compositional range of local resources (based on comparisons with sediments from within a 10 km site radius). Results show a clear distinction between sediment-defined local and non-local ceramic compositional groups. Two discrete local ceramic resources have been previously identified and we confirm a third local resource for a major class of EIA handmade wares and cooking pots. This third source appears to derive from a residual resource on the Troy peninsula (rather than adjacent alluvial valleys). The presence of a group of large and heavy pithoi among the non-local groups raises questions about their regional or maritime origin.     

Selecting and Sampling Shipwreck Timbers for Dendrochronological Research: practical guidance

In this article, we provide practical and straightforward guidance for the selection and sampling of shipwreck timbers for dendrochronological research. We outline sampling strategies and present informative figures that illustrate how to proceed in a variety of scenarios that archaeologists regularly encounter. However, in order to fully exploit the potential of tree‐ring research on these objects, we would urge archaeologists to involve dendrochronologists during the project planning phase to carefully plan and conduct adequate sampling of shipwreck assemblages.     

Sampling and analysis of geothermal fluids

Sampling of geothermal fluids presents some problems not encountered when sampling surface and nonthermal ground waters. Specific collection techniques are required to obtain representative samples because of the elevated temperature and boiling of these fluids, the effect of exposing them to the atmosphere and cooling of the samples. Sample treatment during collection depends on the analytical method to be used. When sampling wet‐steam wells, both the liquid and the vapour fractions should be collected at the same fluid separation pressure. When sampling fumarole steam, maximum information is obtained if the total discharge is collected into a single container without separating the gas and the steam condensate fractions. Silica polymerization affects the solution pH. The only way to obtain reliable pH measurement of a water sample supersaturated with respect to amorphous silica is to measure it on site, before the onset of polymerization. This paper provides an outline of the geothermal sampling techniques and analytical methods currently in use in Iceland. Sampling of hot‐water and wet‐steam wells is described, as is sampling of hot springs, fumaroles and gas bubbling through hot‐spring waters. Detailed procedures are given for the analysis of total carbonate carbon and total sulphide sulphur in geothermal water and steam condensate samples.     

New approaches to the study of tourist experiences in time and space

Nowadays, a growing number of researchers are investigating subjective attitudes of people toward their environment with ever-increasing spatial and temporal resolutions. It seems that researchers' interest in daily experiences is not merely a passing research fad, but rather that individuals in current societies find more interest in their own momentary experiences. They talk about their affective states, they spend considerable portions of their income on intangible experiences, and they instantly share personal ‘moments’ through various online social media platforms. These trends are even more apparent in the tourism and leisure industries which aim to generate positive experiences among individuals. This research note points out new directions in the exploration of experiences during tourism and leisure activities. It discusses a new relevant concept, subjective momentary experiences on one hand and presents novel methodological opportunities on the other. In order to portray these new trends, a case study that describes the episodic experiences of festival attendants in a high tempo-spatial resolution is presented.     

Functional analysis of prehistoric flint tools by high-power microscopy: A review of West European research

The present paper is a review of the functional analysis of prehistoric flint tool edges by means of high-power microscopy. The article, which focuses exclusively on West European research, discusses a series of methodological issues and problems related to the development and distinctiveness of the so-called wear polishes, produced by the various materials with which prehistoric stone tools came in contact. A selection of functional observations on tool use from the Upper Paleolithic, the Mesolithic, and the Neolithic periods is presented. The archaeological part of the review is concerned with two trends in functional analysis, namely, (1) controlled site-specific studies with different levels of foci and (2) thematic studies of particular tool types, e.g., endscrapers, burins, and unmodified débitage. Finally, problems concerning the interpretation of hafting and of multiple tool use are discussed.     

Seasonality of birth and diet of pigs from stable isotope analyses of tooth enamel (δO, δC): a modern reference data set from Corsica,France

Since domestication during the mid 11th millennium BP in the Near East and the 8th millennium BP in China, the pig has played an important role in human diet and economy. The objective of this study is to evaluate the potential of stable oxygen and carbon isotopes sequential analyses of pig tooth enamel to investigate pig seasonality of birth and diet, as these are important parameters for the reconstruction of pig herding strategies in ancient societies.