Context is not completely clear at this time. May be a surface/ pavement on top of 15053 wall, but may be of some other use. Context continues west unto the sondage wall. SU 15048 is cut by 15046 and its fill 15047 partially covers 15048. 15048's tiles which were cut by 15046 remind ELM of broken tiles sticking out of a bulk wall.
SU 15048: view toward the north