• X-ray fluorescence reveals: The story behind ceramic artefacts

    26 September, 2014 | Arkeologi, Bevarande, Föremål, Samlande | 0 kommentarer

    Den nyzeeländska forskaren Josh Emmitt gästbloggar om sitt besök hos oss den senaste månaden. Vad berättar analyserna av skärvor från det fördynastiska Egypten? (PÅ ENGELSKA).

    Hello everyone, I am a PhD Student at the University of Auckland and have been working this past month at the off-site storage facility of the Medelhavsmuseet in Tumba. I am currently in the third year of my PhD and am investigating the ceramics from a number of Neolithic and Predynastic sites in Egypt, to find out more about settlement and mobility during this time. Since the end of July I have been travelling around the United Kingdom and Sweden examining ceramics in museum collections. Next month I will be in Vienna doing the same before returning home to New Zealand. Over the course of the month I have analysed 2531 ceramic artefacts from the Neolithic occupations of Merimda and the Fayum that are in the collection here in Sweden. I have also used a portable x-ray fluorescence (pXRF) machine to take readings from 1038 of those analysed artefacts over the month (Figure 1).

    Figure 1: Me using the pXRF to take a reading from a ceramic sherd

    Figure 1: Me using the pXRF to take a reading from a ceramic sherd

    The pXRF was kindly lent to me by Bruker UK for the duration of my research. The machine, with the right settings and calibrations, records the elemental composition of an object. In some cases readings can be used to tell if an object is real or fake, such as in art museums. For ceramics, it is useful for identifying groups of artefacts, what sources of clay were being used, and potentially identifying trade between sites. The benefit of the pXRF is that it is small and light, looking like a ray gun from Star Trek and weighing under 10kg. This is good because it can easily be transported on planes and carried to different museums.

    I have been a part of the University of Auckland team on the UCLA/RUG/UOA Fayum Project since 2009 and completed my Honors and Masters theses on subjects related to this area. The project has been conducting a large-scale surface survey of the area to identify artefact density and also investigate mobility, settlement, and environmental change in the area during the middle Holocene. This involves looking at all types of artefacts, not just the ceramics I am analysing.

    The challenge with working in Egypt is the inability to remove objects from Egypt for further analysis. This restriction was introduced in the 1970’s to help stop the illegal trade of antiquities, but it also had a negative effect on research. As a result the types of analyses which can be done on artefacts in the field can be limited, especially when specialised machinery which is heavy and/or expensive is required. This is where the collections in museums are important.

    The collections housed in museums from Egypt across the world represent a vast wealth of information and in some cases is available for analysis which could otherwise not be done. As well as this the collections have two other important aspects for researchers. One is that a number of the sites which these artefacts come from, like Merimda, are now largely or wholly destroyed or under modern agriculture and therefore not accessible. The other reason is that these collections in some cases represent the only complete examples of artefacts which have been found to date. For example in the Fayum the ceramic vessels in museums are the only known examples from the Neolithic occupation, meaning that they are important for the interpretation of the thousands of sherds which we find in the field today. While some of these ceramic artefacts housed in museums may not look particularly nice or be in the best condition, in some cases they are more important than the objects of gold and silver on display.

    The collection of Merimda ceramics in the Medelhavsmuseet is important for Sweden as well. The excavation which took place in the 1930s, although run by an Austrian team, also consisted of a large number of archaeologists from Sweden and this was one of the first times that Sweden had had an involvement in Egyptian archaeology. As a result of this involvement the Medelhavsmuseet has the largest collection of Merimda material anywhere and a substantial collection of Neolithic and Predynastic objects from around Egypt. A fraction of these artefacts are housed in one of the best displays of those artefacts which I have seen at the Medelhavsmuseet. If you visit, make sure to have a look at the impressive collection of Merimda ceramic vessels which are on display, and know that those are only the tip of the iceberg (Figure 2). The staff at the Medelhavsmuseet have been very welcoming and facilitating to my research, and for that I owe them my heartfelt thanks.

    Figure 2: The Merimda vessels on display at the Medelhavsmuseet

    Figure 2: The Merimda vessels on display at the Medelhavsmuseet

    To find out more about my previous research and that of the project you can find it in the links in the text above or at my Academia page. Also, the University of Auckland team keep a blog of our work in Egypt and of our experiences in the field and has more entries from this research trip by me, which you can find at http://digdiaries.ac.nz/fayum/. I will be posting more blogs there about my research in Vienna!

    Josh Emmitt, PhD Student at the University of Auckland.