ARCHAEOMETRY AT SLOWPOKE‐TORONTO

This paper describes the archaeometric research conducted at the SLOWPOKE Reactor Facility of the University of Toronto (SLOWPOKE‐Toronto) during its existence from 1971 to 1998. The contributions to student teaching and research are described, and the total contribution of the facility to studies of an eclectic assortment of ancient and historic materials is addressed.     

POST BUILT STRUCTURES AT DANEBURY HILLFORT AN ANALYTICAL SEARCH METHOD WITH STATISTICAL DISCUSSION

Summary. A computerised search method is described to identify every possible rectangular structure within set parameters from post hole distributions. Results are obtained from a dense distribution within Danebury hillfort and tested statistically by comparison with results from simulations and a mathematical model. The most likely structures are isolated by analyses of size, shape and orientation. A further comparison, with the results of an independent visual analysis of the same area, allows some comment to be made on the efficiency of human pattern perception and the validity of existing preconceptions concerning rectangular post-built structures.     

SYNCHROTRON FTIR MICRO‐SPECTROSCOPY APPLIED TO THE STUDY OF POLISHED SERPENTINITE ARTEFACTS: A NON‐DESTRUCTIVE ANALYTICAL APPROACH

In prehistory, serpentinite was one of the most frequently used raw materials to produce polished stone artefacts. Several conventional analytical techniques can be applied to identify the serpentine minerals, but their application generally requires a powdered sample. This implies that the artefacts to be analysed must be damaged, and the possibility of analysing a mixture of different serpentine polytypes is high. The use of spatially resolved techniques is therefore a necessity to overcome this problem. Several thin sections of serpentinitic rocks and prehistoric axes have been analysed by synchrotron radiation Fourier transform infrared micro‐spectroscopy. The spectra were acquired directly on specific points of polished stone artefacts and this allowed the recognition of the different polytypes of serpentine minerals without causing any damage to the objects. The results show the infrared micro‐spectroscopy technique to be a useful tool for the characterization of archaeological lithic material.     

ANALYSING ARCHAEOLOGICAL BASALT USING NON‐DESTRUCTIVE ENERGY‐DISPERSIVE X‐RAY FLUORESCENCE (EDXRF): EFFECTS OF POST‐DEPOSITIONAL CHEMICAL WEATHERING AND SAMPLE SIZE ON ANALYTICAL PRECISION*

Energy‐dispersive X‐ray fluorescence (EDXRF) has been commonly used to determine geological sources of volcanic glass artefacts, but its ability to discriminate between basaltic sources is less developed. We examine the precision and accuracy of non‐destructive EDXRF for basalt artefacts by analysing varying size and weathering characteristics. The experiments identified no appreciable effect in reproducibility or measured composition due to thickness (down to 1 mm) or natural weathering of pre‐contact flake scars for the 17 elements measured in this study. Samples with surface area less than 100 mm², however, show significant variability in measured composition and reproducibility.     

ANCIENT OMPHALOS AT DELPHI: GEOMETRICALLY A SPACE‐INVERTING ANAMORPHOSCOPE

Whether the artisan who made the Omphalos at Delphi over 2500 years ago recognized the optical transform properties of its shape or not, its geometrical features are nevertheless those of a space‐inverting anamorphoscopic mirror. Specifically, it is similar in shape to a circle‐inverting anamorphoscope. We speculate that select members of the ancient religious sect at the Temple of Apollo at Delphi realized the symbolism of inverting all of space outside the Omphalos into the image field inside its base, thus making it the virtual centre of the World.