Scientists at the University of Manchester have developed a method of dating archaeological objects - using water and fire to open their 'internal clock'.
A simple method promises to be an important technique in dating ceramic materials, like radio carbon dating for organic materials like wood or bone.
A group of scientists from Mancherster University and Edinburgh University have discovered a new technique they call 'rehydroxylation dating method' that can be used for baked ceramics such as bricks and tiles, and handmade ceramics.
Working with the London Museum, the team was able to identify brick patterns from the Roman, Medieval and modern times very accurately.
They claim that this technique can be used to date objects up to 2000 years old - but believe that this method is capable of dating the 10 000-year-old artifacts. .
This method is based on the fact that baked ceramic materials will start to react chemically with moisture in the air as soon as it is removed from the furnace. This process continues to cause the weight of artifacts to increase gradually - the higher the age of the material, the greater the weight added.
In 2003, the team of Manchester and Edinburgh discovered a new law that can accurately determine the rate of reaction between ceramics and water changes over time.
Applying this rule is fundamental to the new dating method because the amount of water associated with ceramics provides 'internal clocks ' that can be used to determine the age of artifacts.
This technique involves determining the mass of a ceramic specimen and heating it to 500 degrees Celsius in a furnace to remove water.
The specimen is then controlled in a precise special measurement device called microbalance, to determine the speed at which the ceramic material combines with water over time.
Using the rule of time, it is possible to analyze the collected information to calculate the time it takes to achieve the weight lost when baked, thereby determining the age of the specimen.
The lead author, Dr. Moira Wilson, lecturer in the School of Mechanical and Aviation Engineering (MACE), said: 'These findings are the result of research for many years. We are very excited about the potential of this technique. It can become the main dating method for ceramic materials'.
'This method can also be used to bring out the average temperature of the material, if the exact firing time is known. This may be useful for climate change studies'.
'In addition, the study offers many other applications, such as the detection of forged ceramics'.
The 3-year project, with a £ 100,000 grant, is funded by the Leverhulme Trust, with a microbalance device measuring a tenth of a millionth of a gram - funded by the Physical Science Research Council (ESPRC). support
Researchers are now planning to find out whether new age determination techniques can be applied to terracotta or porcelain artifacts.
The team includes Dr. Moira Wilson, Dr. Margaret Carter, Professor William Hoff, Ceren Ince, Shaun Savage, and Bernard McKay from Manchester University, Professor Chris Hall from the School of Engineering and the Center for Materials Science and Mechanical engineering of Edinburgh University and Ian Betts of London Museum.
References:
Dating fired-ceramics using long-term power-law rehydroxylation kinetics.Proceedings of the Royal Society A, May 20, 2009