Fill of the cut (SU 6256) in the bedrock. Its deposition may be associated with either the construction of the wall SU 6231 which was an addition to the total length of the north-south wall on the western side of the room or with the well head SU 6236 to the east of the later wall addition. However given the position of the wall it is not possible to tell which the stone is in phase with without further undercutting excavation of the wall.