THE DESIGN OF EVALUATION OF ASSAYS OF TRACE ELEMENTS IN A FOSSIL BONE*

The flame atomic absorption spectroscopy method of analysis of trace elements (Mn, Sr, and Cu) in a mammoth's bone and the method of estimation of the data using regression analysis are described. The concentration fields of the single elements in a cross-section through the bone are well described by a fourth degree polynomial. The minimum values and their coordinates have been determined. A method of determination of the original concentrations of trace elements in fossil bones is described further. The approximating features of the regression exponential equations and of the diffusion functions of various shapes were determined and a method for calculating the concentrations and diffusion properties of the bones once deposited in the soil is suggested. The original trace element concentration can be estimated by extrapolation of a suitable exponential or diffusion function.     

A MAGNETIC SURVEY OVER LA MAJA,AN ARCHAEOLOGICAL SITE IN NORTHERN SPAIN

A Roman archaeological site in northern Spain (La Maja, province of La Rioja) includes pottery workshops, part of an important ceramic industry that developed from about the first century BC to the first century AD. A geophysical study was planned to determine the extent of the industrial complex in the vicinity of an excavated kiln. Magnetic observations were done on a grid of 30 × 36m, with a sampling interval of 1m. Two dipolar-shaped anomalies were found: one in the north-east and the other in the south-west of the area. Low-pass and band-pass filters were used in the Fourier domain to enhance the characteristics of the magnetic data and to remove noise and undesirable shallow features. Three-dimensional polygonal prisms were used to model the magnetic anomalies based on palaeomagnetic measurements performed over an uncovered kiln that helped to constrain the induced and remanent parameters of the magnetizing fields.     

3D Digital Documentation,Assessment, and Damage Quantifi cation of the Al-Deir Monument in the Ancient City of Petra,Jordan

Abstract

The rock-cut monuments in the ancient city of Petra in Jordan form an outstanding tangible heritage site. Unfortunately, this important part of the world's cultural heritage is gradually being diminished due to weathering and erosion problems. In this research, an approach combining in situ surveying and laboratory analysis is applied in order to provide sufficient and comprehensive data regarding the documentation and evaluation of the status of the Al-Deir monument in Petra. The purpose was not only to quantify the damage, but also to make a first step towards creating a 3D monitoring programme of the deterioration rate. The approach presents a correlation study between the environmental condition and the surface weathering damage, using 2D mapping of the weathering form and accurate 3D realistic modelling from laser scanning and digital photogrammetry. The 2D mapping provides detailed weathering damage information for the entire stone surface of the monument, whereas the 3D modelling provides information on the spatial distribution and texture of the damage. Additionally, the 3D digital model can provide reference data as an exact guide to the restoration needed. In order to support the visual presentation of 3D surface details, a hybrid approach combining data from laser scanning and digital imagery was developed.

Studies of stone texture and spatial distribution of soluble salts were carried out at the monument in order to explain the mechanism of the weathering problem. Relative humidity, temperature, and wind are the main factors in the salt damage process. In order to study the effect of these conditions in the salt crystallization process a series of fieldwork investigations and laboratory work were undertaken. The results show that visible zoning of weathering damage is correlated to different salt concentrations.     

ALTERATION PROCESSES OF POTTERY IN LAGOON‐LIKE ENVIRONMENTS

Post‐depositional processes in pottery can give rise to chemical and mineralogical alterations, the extent of which is closely related not only to the microstructure and composition of the potsherds, but also to the chemical–physical conditions of the burial environment. The present paper describes the characterization of post‐depositional alterations and identification of processes involving pottery buried in lagoon‐like environments. A set of various types of Roman transport amphorae and African Red Slip ware (ARS), collected from two archaeological sites characterized by a lagoon‐like depositional environment and showing evident changes in the original colours, was analysed by a combination of microstructural, mineralogical and microchemical approaches. The formation of pyrite after hematite, jarosite after pyrite and microstructural substitution features are interpreted here in terms of the chemico‐physical conditions of the burial environment and their evolution in time.     

MATCHING PAST AND PRESENT CERAMIC PRODUCTION IN THE BANDA AREA (GHANA): IMPROVING THE ANALYTICAL PERFORMANCE OF NEUTRON ACTIVATION ANALYSIS IN ARCHAEOLOGY USING MULTIVARIATE ANALYSIS TECHNIQUES*

The transfer of advances in chemometrics into archaeometric research opens up a wide range of new application possibilities in this rapidly developing field. Neutron activation analysis (NAA) of ceramic samples from the Banda Traditional Area (west‐central Ghana) combined with chemometrics allowed us to establish a link between current and ancient systems of ceramics production in the historic settlements of Kuulo Kataa and Makala Kataa. Principal component analysis (PCA) and the soft independent modelling of class analogy (SIMCA) method were applied to the Das Dores Cruz data set in order to unequivocally determine the geographical origin of the diverse archaeological samples. After global autoscaling pretreatment, PCA analysis showed a clear difference between samples from different locations. The classification models obtained by SIMCA showed a classification ability of 100% and a prediction ability of 97.7%, with a mean sensitivity of 84% and a specificity of 100% for the three categories. The application of SIMCA showed that some NAA variables (elements) were more important than others in terms of geographical classification. With the class models that we obtained, we were able to determine the origin of the ancient remains. SIMCA has proved to be a powerful technique for the class modelling of archaeological data.     

TOWARDS A NEW APPROACH TO ARCHAEOMAGNETIC DATING IN EUROPE USING GEOMAGNETIC FIELD MODELLING*

We introduce a new approach to producing secular variation curves for archaeomagnetic dating, using global geomagnetic field modelling techniques. Using published palaeosecular variation curves for five European locations as input, and a previous global model for regularization, we produce a model for the period ad 0–1900, which reproduces the input curves within their 95% confidence intervals, and successfully fits data from other regions in Europe. Our global model performs as well as a previous regional model, but additionally ensures consistency with physical constraints. We show that the curves currently used for dating are not mutually consistent, and therefore that in the future this new approach will provide more reliable curves for archaeomagnetic dating.