In SLT5 we started locus 20 at light colored clayey layer at -115cm b.d. Much decreased artifact count. Clay floor at the bottom of this locus is locus 21.
In SLT4 baulk removal locus 13 is light tan layer. Arkadi is on site with some colleagues and confirmed this layer is fine silty clay, not ash. At floor level under baulk is a burn feature just east of (and probably contiguous with) locus 9 burn feature. Took a large radiocarbon sample from this locus and sketched in notebook. Doorway in northwest corner of structure is emerging nicely.