07.18.06 Today we removed 40 cm from 14 of the 20 trenchettes, and this method seems to be good, because it allowed us to find trenchettes that bottomed out quickly. 3 (f, g, and n) hit what appears to be bedrock, or at any rate, rock that is too big to remove. The morning sun makes shadows too deep to be able to see into the trenchettes, so we will knock out the last 6 in the morning tomorrow. We are focusing on the trenchettes near the trench WSK, to see whether we can find the same clay surface. In S, which we dug deeply today, we have gone down to about 90 cm below ground and found a clayey matrix but no surface yet. Hopefully tomorrow!