DISCRIMINATION BETWEEN ETRUSCAN POTTERY AND RECENT IMITATIONS BY MEANS OF THERMAL ANALYSES

Black bucchero and red pottery of Etruscan production (Cerveteri, seventh-fifth century B.C.), made from the local Pliocene clay, acquire the property of quickly adsorbing and releasing water after heating up to 300°C. Thermal analysis thus allows easy discrimination between ancient artefacts and recent imitations found to be impervious to water.     

Late Glacial and Holocene Vegetation History at Dublin Bog North-Central Tasmania

Percentage and influx pollen analyses of a 9.17 m core from Dublin Bog give a post last glaciation vegetation history (-13.6 to 0 ka BP) for the upper Mersey Valley. Herbaceous vegetation of Gramineae, Compositae and Chenopodiaceae developed rapidly after deglaciation and lasted until 13.2 ka BP. Around 13 ka BP Eucalyptus woodland and forest developed rapidly on the valley floor. At the same time Pomaderris apetala became an important understorey shrub/tree, and Phyllocladus aspleniifolius rainforest developed in the gullies on the upper slopes of the Mersey Valley and in the valleys to the west The major change in climate from late glacial cold (and probably drier conditions) to warm humid conditions similar to present occurred between 13.2 and 13 ka BP. Wet sclerophyll Eucalyptus forest occupied the valley throughout the post glacial and attained its maximum development between 11.7 and 8.4 ka BP. Rainforest never occupied the valley floor extensively. Phyllocladus aspleniifolius sattained an early maximum about 13 ka BP. The peak of Pomaderris apetala and expansion of Dicksonia antarctica suggests that the climate was warmer and wetter between 10.3 and 8.4 ka BP than at other times. Nothofagus attained its maximum development between about 10.3 and 6 ka BP. Both sclerophyll and rainforest vegetation associations in the upper Mersey Valley appear to have been very stable and similar to their present floristic compositions during the Holocene. Aborigines occupied the valley by 10 ka BP. Fire was always present in this marginal area between the wet climate of western and the dry climate of eastern Tasmania. Fire did not cause replacement of rainforest by wet sclerophyll forest on the valley floor, though it could have prevented rainforest establishment     

CORRELATION BETWEEN SPECTRAL,SEM/EDX AND ELECTROCHEMICAL PROPERTIES OF MAYA BLUE: A CHEMOMETRIC STUDY*

Visible spectra, composition from SEM/EDX and solid‐state electrochemical data are correlated for a set of 12 Maya Blue samples from different archaeological sites of Campeche and Yucatán (Mexico). In addition to indigo and dehydroindigo, indirubin and other possibly indigo‐type compounds can be detected in Maya Blue samples. Application of hierarchical cluster analysis techniques allows similarity relationships to be established between samples from different sites, confirming prior results which suggest that the preparation of Maya Blue pigment evolved with time during the Maya culture following a ramified scheme.