This deposit of basalt and tile seems to be part of fill filling a cut into dumping layers (su 5567 for example). The cut edges have been obscured by perhaps backhoe interference and by edges of blocks themselves except along bottom W edge where it may be identified (and will be labelled and shot in at later date). This su is in alignment with su 5561, north of the orthostate slab and thus is probably from the same filling episode. This fill may be a foundation for a later wall or may itself be a retaining wall for the dumping activity in this area.