Bitumen-painted ceramics from Tell Sabi Abyad: an unexpected discovery
The excavations between 1996 and 1999 in the
, which was destroyed in a violent fire at around 6000 BC, have yielded an intriguing group of ceramics. The vessels are decorated in a most curious manner, always with a very distinctive mat, fugitive black pigment. The rough, primitive-looking decorative style differs remarkably from any other found in the Burnt Village, showing simple vertical stripes, rough 'fish-hook'-like designs and thick dots. We suspected that there was something special about these vessels. What kind of paint could this be?
Loe Jacobs and Bram van As, archaeologists associated with the Department of Pottery Technology of Leiden University, decided to submit some of the sherds to a 'refiring test', which means firing them in a potters' kiln at a temperature of 750 °C . Usually this treatment does not affect the Late Neolithic painted designs significantly. In this case, however, the painted decoration simply disappeared. The suspicion arose that we were dealing with an organic pigment. We contacted Jaques Connan, Research Director of the Laboratory of Geochemistry at the Centre National des Recherches Scientifique in Strasbourg, France. Connan quickly discovered that the pigment was, indeed, an organic substance. In fact, it was bitumen.
Bitumen is an organic natural resource that closely resembles asphalt. In the Near East bitumen erupts naturally at a number of locations. Well-known sources are found near Hit in northern Iraq (see photo). In antiquity people used bitumen for a wide range of purposes. The imposing temple mounds (ziggurats) were sometimes strengthened with layers of bitumen. It was commonly applied as glue, for instance to assemble
composite flint tools
, or to repair a broken pot. At Susa (western Iran) people used a bituminous rock (not bitumen mastic, as was thought in the beginning) for artistic sculpture. The natural bituminous rock is found at a distance of about 150 km from Susa. Recently, British archaeologists in Kuwait made a unique discovery: a
made waterproof with bitumen.
In the ancient Near East people attributed all sorts of magical and medicinal properties to bitumen. In Kuwait people used it until very recently as a medicine against stomach problems - although it may be doubted if this really worked. In our own, western, society we still use bitumen in the form of asphalt to waterproof roofs, to secure dikes, for instance at the Oosterschelde dam in southwestern Holland, and to cover pavements and, of course, our highways. Daily millions of Europeans travel over endless stretches of contemporary bitumen.
How did people make this pottery?
In this period all pottery was still made by hand. The potter's wheel was invented about 3000 years later. The potter selected good clay somewhere close to the village, and mixed it with copious amounts of chopped straw. This was necessary to improve its strength and to prevent cracks during drying. The vessel was built up step by step, by adding one ring of clay after another. This shaping method, termed the 'coiling' technique, is still being practised today by modern studio ceramists and by traditional, non-western potters. After drying the vessels were fired in a simple pit.
A bitumen paint can only be applied after firing. After all, because bitumen is an organic pigment it would simply disappear during firing. In all likelihood, people decorated the vessels immediately after firing, when they came hot out of the kiln. They may have used elongated lumps of bitumen to scratch the stripes and dots on the still warm surface. The heat partly melted the bitumen, so that the design attached itself to the vessel surface.
As an international expert in Petroleum Geochemistry, Jacques Connan was connected for most of his professional career to the French petroleum company Elf Aquitane (now Total). This company, with a long experience of petroleum exploration in the Near East, has gathered through time analyses on the chemical properties of quite a number of natural oil seeps and reservoir oils in the region. A perfect source of references! The organic components of oils and bitumens differ from source to source, giving each source its specific 'finger-print'. Using statistical procedures, Connan can investigate which natural sources match the chemical composition of the archaeological bitumen best.
The graph shows the Sabi Abyad bitumen-painted sherds (Sabi) together with bitumens from a range of other archaeological sites, and from a number of contemporary sources. The more closely two samples resemble each other chemically, the more closely they are situated to each other in the graph. A comparison suggests that the bitumen sources that we had expected most of all, those near the modern town of Hit, were not used. The Hit sources were used very frequently throughout antiquity, but in our case the chemical compositions are simply too different. Two other sources, however, do give a good match: those near Zakho and near Kirkuk, two modern towns in northern Iraq. The prehistoric inhabitants of Tell Sabi Abyad apparently got their bitumen from far: the material covered a distance of about 500 km before reaching the site.
The bitumen shows that the Late Neolithic occupants of Tell Sabi Abyad were certainly no isolated peasants. More and more we discover how successfully they were able to reach communities living in other parts of Syria and surrounding countries. Through these social networks they gained access to a range of goods that were locally unavailable: volcanic glass (obsidian) and raw copper from Turkey, costly stone from Iran and Afghanistan, and also bitumen from northern Iraq. These bitumen-painted ceramic vessels represent the oldest currently known from the Near East.
Archaeologists are also highly interested in the symbolic meaning of decorative styles. In our own society, too, using the right type of gear shows who you are (or wish to be): Nike shoes, a hip Swatch wristwatch, a costly Bentley parked where the neighbours can just see it, and so on. In prehistoric Syria, too, people tried to shape their own way of life by using particular objects. Around this time, at about 6000 BC, the pottery changed dramatically. All across Syria and northern Iraq, people began using complexly decorated, high-quality ceramics, so-called Fine Ware. The coarse, bitumen-painted style, on the other hand, technologically falls within the older, 'traditional', way of making pottery. Did certain groups of people perhaps reject the new, fashionable Fine Ware by adopting bitumen-painted ceramics? Does the bitumen-painted style represent a last-ditch resistance by local die-hards? Whatever may have been the reason to apply this special decorative technique, the bitumen-painted style disappeared entirely and foregood soon after.
Currently we are broadening our research with the investigation of additional samples of bitumen-painted sherds. We have also included some vessels that were repaired with bitumen in antiquity: could this be the same material that was used for painting? Recently the excavations have yielded some lumps of raw bitumen: could there be the instruments people used to decorate the vessels? We hope to gain an answer to these questions soon.
Those who wish to see the bitumen-painted vessels for themselves ... must come to Syria! All archaeological finds from Tell Sabi Abyad must remain in the country. The study was done on a small sample of sherds for which an export permit was obtained.
J. Connan, O.P. Nieuwenhuyse, A. van As and L. Jacobs, 2004, 'Bitumen in Early Ceramic Art: Bitumen-Painted Ceramics from Late Neolithic Tell Sabi Abyad (Syria)', Archaeometry 46: 115-124.
O.P. Nieuwenhuyse, J. Connan, A. van As and L. Jacobs, 2003, 'Painting Pots with Bitumen at Late Neolithic Tell Sabi Abyad (Syria)', Neo-Lithics 2/03: 22-25.
J. Connan, 1999, 'Use and Trade of Bitumen in Antiquity and Prehistory: Molecular Archaeology Reveals Secrets of Past Civilizations', Philosophical Transactions of the Royal Society London B 353: 33-50.