SU 8221 is a post hole for a structure that pre-dated the majority of the area I structure. It is possibly to be associated with floors SU 8167, 8214, 8265, and the surface into which it is cut (SU 8225).
cut for post hole filled by SU 8219
SU_8221_8225_3.JPG
Surface cut by SU 8065; Cut for post hole filled by SU 8219