The general locus, SLT9.12, is a pit feature that Roman Hovsepyan came out to systematically sample for flotation. This including sampling soil layers in the pit at 10cm depths. The 12b designation is this layer of the pit from which he recovered a pea seed that we radiocarbon dated. In that sense 12b is sort of a sub-locus of the pit. I will need consult Roman's notes see how many sacks of soil he took for sampling, but it was around 3, which I denote below. The soils was floated, which I indicated as 'screened' below.