Since we discovered the ditch with a channel made of pitched tiles, we have been asking ourselves three questions: what was the channel’s function, how far does it it extend, and what is its relationship to the wall in B2? By the end of last week, we had traced the tile feature west from operation B1 to operation B2. When we realized that the channel extends beyond the edge of the wall and likely beyond the western edge of B2, we decided to section B2 in order to save time and to address the question of the stratigraphic relationship between the channel and the wall.
As we cleared the fill off the top of the tile feature, we realized that portions of the wall had collapsed on top of the channel, indicating that at least the top of the channel remained open up until the period of abandonment of the site. However, the wall itself was constructed after the channel. The top of the tiles are several centimeters below the bottom of the wall and the wall was founded on the natural (i.e., geological) sediment, which in this area of the site is clay rather than sand. Unlike B1, where the channel is cut into sand, in B2 it was cut into clay. Those sedimentary layers overlap each other almost exactly at the line between our two operations (B1 and B2).
But what was the purpose of the channel? When we first exposed the pitched tiles in B1, we had several theories: a burial, a drain, a stokehole for a kiln or a bath house. Given the length of the feature, it was most likely a drain. But it was clearly blocked by an end tile on the eastern end. We removed the fill on either side of the last set of tiles and then removed both of those tiles and the end tile. To our surprise, the ‘drain’ had no bottom! On the eastern end it was constructed directly on the sand sediment. To know for sure, we even dug out a section of the sand. There is nothing there.
Now that we have exposed the channel across most of B2, we have sectioned off another set of tiles next to the portion of the wall that was constructed more systematically and founded at a deeper level than the western end. Here our plan is to excavate the fill on either side of the tiles and then to lift them (as we did on the eastern end) to see whether there is a bottom, or whether this section was also constructed on the natural sediment (in this case, clay).
We also extended the excavation area to the south (operation C2). Here we encountered a dense deposit of roof tiles and other building material (including a chunk of cocciopesto flooring) but no pottery at all. We found 69 fragments of pan tiles, 74 pieces of imbrices (rounded tiles that fit over the joins of the pan tiles to keep rain from coming in). Altogether, we removed 153.24 kilograms (337.13 lbs) of tile, all from an area of only 1×4 meters. This material either collapsed from a building very close by or was redeposited here from somewhere else on the site. We will have to wait until next year to find out where that building might be.
The students will spend the next week helping to process the finds and working with the museum in Castiglione del Lago.