THE DATING OF ANCIENT CHINESE CELADON BY INAA AND PATTERN RECOGNITION METHODS*

In 2005, sherds of a special type of ancient Longquan celadon ware were excavated at Maojiawan, in the city of Beijing, China. Although archaeologists agree that these sherds were fired in the period between the Yuan and Ming Dynasties, their specific date is unclear. In order to solve this problem, five other groups of ancient Longquan celadon sherds of known date were selected as reference samples. The elemental body composition of all the sherds was determined by Instrumental Neutron Activation Analysis (INAA). Using the same principles as in provenance research, pattern recognition methods were used to build classification functions to specify the date of the unknown sherds. After analysing the experimental data by discriminant analysis, three classification functions were built. All the unknown sherds were classified as Ming Dynasty. This prediction is well in accordance with the fact that these sherds are similar to other Longquan Ming celadon, and so they should be fired in the same dynasty. This also verified the judgement of the Beijing Institute of Cultural Relics.     

A NEW DATING METHOD FOR HIGH‐CALCIUM ARCHAEOLOGICAL GLASSES BASED UPON SURFACE‐WATER DIFFUSION: PRELIMINARY CALIBRATIONS AND PROCEDURES*

The first European settlers came to North America in the early 17th century using glass in the form of containers and decorative objects. Thus, glass is a horizon marker for all historic period settlements and a potential source of chronometric dates at archaeological sites belonging to the historic period in the Americas. We have developed a new absolute dating method based upon water diffusion into the surface of manufactured glasses that predicts diffusion coefficients based upon variation in glass chemical constituents. Low‐temperature (< 190°C) hydration experiments have been performed on a set of five high‐calcium (21.7–28.3%) glasses that were used to manufacture wine bottles from the 17th?19th centuries. Infrared spectroscopy and secondary ion mass spectrometry was used to model the water diffusion/alkali exchange process. The ability of the model to accurately predict archaeological ages was evaluated with artefacts recovered from ceramic‐dated contexts at Thomas Jefferson's plantation known as Monticello.