Preserving the Past for a Stronger Future: Nuclear Techniques for Cultural Heritage Research
Bringing archaeologists and scientists together
At the mouth of the Amazon River, 1500 years before Europeans arrived in South America, there emerged one of the most intriguing indigenous societies of the Americas, the Marajoaras. An exuberant and aesthetically driven culture, they are known for their pottery, which—both highly complex in form and decoration—has been studied intensively since the 19th century in relation to vessel function, production processes and style.
For archaeologists, the study of such ceramics may provide answers to key questions on diet, technology, social organization and religious beliefs of past civilizations. Nevertheless, they are limited in their availability to identify paste composition and the source of raw materials, as well as aspects of trade and transport. In order to achieve a better understanding of these ceramics and their contexts, an interdisciplinary approach that incorporates different analytical methods and cutting-edge technology is required.
By analysing the chemical properties of ceramic materials, scientists are able to determine the chemical composition and concentration levels of an object’s trace elements, thereby allowing them to better determine the materials from which the pottery was manufactured. Several analytical techniques can be used to determine trace elements, such as instrumental neutron activation analysis (INAA), X-ray fluorescence (XRF) and electron spin resonance (ESR). The IAEA, through its coordinated research projects, works with Member States to spread knowledge and expertise in these areas and therefore help pave the way for future collaboration between archaeologists and nuclear scientists. As a result, during the last decade important work on ceramic studies worldwide, covering important topics such as ceramic production, technological change, ceramic use and distribution and social boundaries have been conducted.
Precision is Key
The aim of this particular project, “The Chemical Characterization of Marajoara Pottery” was to find a signature for archaeological Marjoara pottery which, when compared with contemporary replicas, could be used to verify authenticity and avoid fraud and illegal commerce. The ceramic powder samples were obtained by cleaning the outer surface and drilling to a depth of 2-3 mm using a tungsten carbide rotary file attached to the end of a drill. Finally, these materials (330 ceramic samples in total) were dried in an oven and stored in a desiccator until weighing.
Precision is the basic premise in this kind of study, and if an element is not measured precisely, it may affect the other well measured elements and the interpretation of data. Therefore, in this project, the precision method was studied using the reference material IAEA-Soil-7 (because the IAEA’s reference materials are recognized internationally as a standard of measurement for different elements, this ensured that their obtained results would be accepted around the world). The results showed the existence of two distinct groups of Marajoara archaeological ceramics, indicating that raw materials used in the manufacture of pre-Columbian artefacts were different from the materials used in contemporary ones.
The provenance of pottery is just one of the many applications of nuclear techniques for cultural heritage research. The nuclear techniques developed and supported by the IAEA have also helped Member States with the conservation of paintings, the dating of artefacts and verifying an artefact’s authenticity (see the recent IAEA publication on ‘Nuclear Techniques for Cultural Heritage research' for more info). Sustainably managing cultural artefacts on behalf of present and future generations is important for any society, though not only for historical purposes. As a non-renewable resource, cultural artefacts are the key to economic competitiveness in many parts of the world, particularly for lower and middle income countries. In this regard, the IAEA is dedicated to helping Member States preserve their past in order to bring about a stronger future.