Archaeometry 18

The technique is useful for the analysis of both major and trace elements in archaeological objects, as it provides accurate analyses of the internal composition of an object from c 10mg samples. Systematic schemes of analysis are described for ancient metals and silicate-based materials (one operator can analyse over 20 bronze objects for 10 elements within 5 days). Examples of the application of flameless atomization are given. Au(abr)

Trace element concentrations are used at present for the identification of samples of a large variety of materials. However, many problems may be encountered, especially wlth respect to sample preparation and interpretation of the results. For instance, an identification procedure cannot give a probability of membership of a group, only a probability of non-membership. The argument is demonstrated statistically. Au

A large number of oak planks that formed the sides to the well indicated, when examined, the design and technical skill involved. The ring-widths of those planks that were made from slow-grown oaks form a valuable long floating chronology for S England. Au(abr)

Calculations allowing for heat losses show that it would be very difficult to exceed 900 C by burning charcoal under reducing conditions in a simple kiln. Much higher temperatures can be reached under oxidizing conditions and hence one could smelt and melt copper in a covered crucible, containing some charcoal, placed in an oxidizing flame above the fuel. Au

Because zircon grains separated from ceramics are more radioactive by orders of magnitude than typical ceramics or soil, no burial information is needed. Nearly all of the natural dose is from internal alpha particles so effects of ground water and supralinearity are negligible. In a test programme on potsherds of known age (including RB sherds), determinations for individual homogeneous (unzoned) grains were within 20% of the archaeological ages; the mean ages of 2 to 5 grains from a potsherd lay within 7% on average of the archaeological age. The main limitations are that zoned zircon grains must be avoided (which makes the procedure somewhat laborious) and a sample at least 1g in size is required. Au

Gas chromatography and mass spectrography were used to test the hypothesis that amphorae which had once contained olive oil would retain traces within the porous walls. Contamination due to environment was checked, and the hypothesis proved correct. Even in doubtful cases the existence of a concentration gradient within the amphora wall will provide confirmation.

Lead levels in ribs from the Poundbury and Henley Wood cemeteries were measured by atomic absorption spectroscopy. The Poundbury bones contained a mean concentration of 112.7 ppm of lead whereas the mean in those from Henley Wood was 65.7 ppm. In both series, mean levels in males were higher than in females but an increase in lead content with age was noted only in the Poundbury bones. At both sites people were exposed to lead levels higher than those of today. Au

Specially-adapted radiation monitoring film is used to detect the natural radioactivity of the characteristic potash content of the glass, using a three-month exposure. Glass of 12th to 15th century date is cheaply and reliably distinguished from that of 18th-19th century; glass of 16th and 17th centuries occupies the middle range of activity. A scintillation probe, while giving good immediate results, requires a low level of background radiation.