This particular pot had been excavated on the final day of our field season, and we had left it filled with its original sediment, thinking there might be something interesting inside (such as someone’s spear points, trousseau or perhaps even an ancestor).
Radiologists ran the pot through a CT scanner, and took the pictures you see on this page. A CT (computed tomography) scan is basically an imaging method that uses X-rays to create pictures of cross-sections of the body, based on the fact that various bodily structures block X-ray beams to differing degrees. The idea is that what works in humans also works in pots; we knew from an earlier classic X-ray that there were areas of different density within the vessel, and we though that the CT scan would tell us what they were.
Unfortunately, although the CT scan did demonstrate the existence of chunks and crevasses within the vessel (see, for instance, the white roundish shadow on the image, below), it showed their shape so clearly that we are quite certain now that they are just rocks, pebbles and cracked clay.
That’s a bit of a shame, but there are still things we can learn. Most particularly, the image can show the uneven thickness of the vessel walls, and thus perhaps indicate how it was made (there exist several pottery-shaping techniques, all of which leave reasonably identifiable micro-traces). It can’t have been easy to shape such a narrow, elongated cylinder.
Also, the manner in which the various layers settled within the vessel can suggest how the remains we’re excavating came to be: did the pot fill quickly, with large chunks of fired earth and charcoal (the collapsing roof and walls of a house in fire)? Or did it become filled with earth over the passage of time, through a natural process of sedimentation, indicating that the vessel lay intact and empty for some period of time?