In WSL we spent the morning breaking a large boulder that we removed from the NE wall. The rest of the day in this trench was spent cleaning. Finally the course of the NE wall is well exposed. We also are coming down onto a clay surface in the extension. A few workers spent the day cleaning the clay in WSL in prep for Arkady's visit. Meanwhile, in WSM we fully exposed the flagstone floor under loci 3 and 4. There is no clay surface above this floor except, oddly, above two rocks. And locus 3 has clay in it's matrix. Carbon sample found in the south corner of room M. When Arkady and his team arrived I gave them a full tour. Ruben says he will submit a report on his observations but for now suffice it to say that the white substance in WSL is not limetone. It's a clay that results from volcanic ash and a lake that would have been here. When the occupants came to the site the decide to carve out of this clay. It's a very pure, clean clay which may have been used either as floor surfaces in other rooms or perhaps even for ceramics. In WSE Arkady is almost certain the bedrock is unworked andesite.