Spent most of the day creating loci for the features and walls in WSN. We also closed locus 65 because we established that the clay deposit beneath the black layer described yesterday is sterile. Rather than continuing to waste time screening sterile clay, I decided to move further into the room, trying to dig only the floor matrix above the clay, which is not level across the room. This also allows us to control for material densities in these lower levels beneath the floor. The new locus is 92. Collected some possible slag samples. Also opened a new locus, 6, in WSM3, which is the level just beneath 3 and also measures 3 x 3, apart from the massive stone boulder in the east corner. The matrix is a tannish brown clay-y silt. Also spent part of the day reading WSAC2 pottery.