Where and when did Stone Age people begin to make life easier by inventing the wheel and getting civilization rolling? Researchers from Mainz, Stuttgart and Lucerne hope to make a contribution to answering this question.
They are currently testing a new method for determining the age of archaeological wood finds as precisely as possible. "The results so far look very promising," says project manager Ingrid Stelzner from the Leibniz Research Institute for Archeology in Mainz.
The restorer is particularly interested in the non-destructive dating of finds. In order to determine the age using the radiocarbon method (C14 dating), which has often been the norm up to now, a sample must be taken from the precious wood find. The C14 dating of finds that have already been treated with a preservative is a particular challenge.
Alternatively, dating by annual rings is possible: With such a dendrochronological age determination, under certain circumstances it can be precisely dated up to half a year when the tree was felled for the piece of wood. The project, financed by the German Research Foundation (DFG), therefore also includes experts from the dendrochronological laboratory in the State Office for the Preservation of Monuments in Stuttgart.
However, it may be necessary to saw up an object in order to make the growth rings visible. The valuable piece of wood remains intact when it is examined with a computer tomograph. CT scanners have been used in archaeological research since the 1990s.
Devices are used that enable a particularly high image resolution with a high voltage. While devices with a voltage of 70 to 170 kilovolts are usually used in medicine, the new device that has now arrived at the future headquarters of the Leibniz Research Institute has a voltage of 450 kilovolts.
A computer tomograph from the Lucerne University of Applied Sciences and Arts is used for the project with eight Stone Age wheels from southern Germany, Switzerland and Slovenia. This makes it possible to examine the archaeological finds of wood inside as well, explains Lucerne physicist Philipp Schütz. "This happens without interfering with the substance and changing or destroying the object."
If the contrast is good enough, all growth rings can be detected and measured in the CT examination, explains project manager Stelzner. It has been shown that this is much easier to do with oak than with maple, for example. In addition, the optical analysis is made more difficult by preservatives, which were used soon after the salvage of the wooden finds for their permanent preservation.
"During the CT examination, we can look inside the wooden objects, even recognize the traces of tools and thus discover the construction instructions, so to speak," explains the restorer from Mainz. The oldest wheel in the project is probably one from Slovenia, which so far can only be dated to around the second half of the 4th millennium BC.
So far it has been assumed that the first wheels were made in the 4th millennium in the northern Black Sea region, roughly in what is now Ukraine. "People back then were definitely happy that they had discovered a way of no longer having to carry heavy things, but being able to roll them," reflects project manager Ingrid Stelzner. "Life must have been pretty tough in the Stone Age."
The first results of the evaluation of the wheel finds are expected by the end of the year. A scientific publication is planned after completion of the project, which is planned for mid-2023.
