New Archaeological Dating Method Uses Water and Fire

A new archaeological dating technique could become as useful for dating ceramic materials as carbon dating has become for testing organic materials over the years. By using two of the basic elements on Earth, water and fire, a research team from the University of Manchester managed to devise a new process to determine the age of the ceramic material, by breaking down its “internal clocks.” With the new “rehydroxylation dating” process, experts could soon get a better idea of the age of the ancient pottery, clay vessels and other ceramic ornaments.

For a long time, researchers have noticed that burnt clay will begin to react with the moisture in the atmosphere around it after it's removed from the fire, and that it would continue to do so over the course of its lifetime. Calculations have also shown that the mass gain is larger when the material is older, and so they used a slightly tweaked version of the law to create their new dating method, e! Science News reports.

The investigators hypothesized that, by heating a piece of clay from a vessel at about 500 degrees Celsius, and then placing it in an ultra-sensitive microbalance, they could assess the amount of mass the clay acquired, which in turn hinted at its age. Using a law inferred from previous experiments, the team could then extrapolate the results obtained over a short period of time, and see the approximate age of their study object.

“These findings come after many years of hard work. We are extremely excited by the potential of this new technique, which could become an established way of determining the age of ceramic artifacts of archaeological interest. The method could also be turned on its head and used to establish the mean temperature of a material over its lifetime, if a precise date of firing were known. This could potentially be useful in climate change studies. As well as the new dating method, there are also more wide-ranging applications of the work, such as the detection of forged ceramic,” UM School of Mechanical, Aerospace and Civil Engineering (MACE) Senior Lecturer Dr. Moira Wilson explained.

Wilson has also been the lead author of a new study detailing the remarkable process, published in the May 20th issue of the respected journal Proceedings of the Royal Society A. The investigation was funded by the Leverhulme Trust and the UK Engineering and Physical Science Research Council (EPSRC). At this point, the experts are weighing the possibility of them using the new technique to assess the age of porcelain, earthenware, and bone china as well.