In the morning we concentrated on loc 2 in new operation So Stlmnt 1. I started a new locus when the soil started to appear more gravelly, calling this loc 5. We only dug another 6-7 cm before coming down on a really dense clay floor, so I maintain this locus number 5 since the gravelly layer we encountered was likely the beginning of the floor. Very few materials in this layer. Since the floor is a 120cm below datum, we've exposed the entire south face of the loc 3 "wall" and it's clear that there is only one course of stones and that they're not resting on a cultural level. In fact, they are floating about 20cm above a dense very dark gray lens that may be the burn feature that could have caused the anomaly. I didn't catch this lens while going down since the soil here is all pretty dark, but when it dried in the afternoon the lens was quite visible in texture and color in the profile below the "wall". It appears to only be present in the central and eastern profiles, and is not visible in the southern or western baulks so it fits the spatial position of the anomaly. I'm ready to conclude that loc 3 is not a wall, but rather collapse stones, and so will try to remove them on Monday to expose the surface of the burned lens (which I designated loc 6). The lens is situated near the top of the loc 5 floor, so it's certainly possible that they are associated and will hopefully produce some good carbon for dating (though none was visible in profile). Meanwhile on the north side of loc 3 stones, we're still going down in loc 4 wash layer since it's very narrow and I was concentrating on the southern larger portion of the trench. When the stones are gone we'll hopefully be able to close out the trench on Monday. Good LB sherds coming out of the wash layers in all parts of the trench, including a really nice small black jar fragment at the lower end of loc 2 above the loc 5 floor.