I closed locus 46 at the beginning of the day, and happened upon a charcoal sample as I was doing so (Ar/Ts.WSM2.46.C14.01 -- a good-sized piece). Then we dug another course in the ring of stones in the middle of the trench (locus 48), and hit bedrock. Locus 49 was dug to examine the way that the SW wall was worked into the bedrock. The locus ran the width of one stone at the bottom course of the wall. From this probe it was evident that the bedrock was much further down on the SW side of the trench than on the NE -- somewhat surprising, since the red clay matrix appeared at a much higher elevation against the SW wall.
I assigned locus numbers to the features and to the walls, and took final measurements for them. The square alignment of stones in the middle of the trench (in which loci 29, 42, and 48 were dug) is locus 50; the flagstone floor locus 51; and the large stone that may have been a column base locus 52. I ran out of time before I could take measurements for the walls -- heavy rain ended work early.