Bulk environmental samples are routinely taken from every viable soil deposit on site. We process all of our soil samples using our own flotation tank next to Trench 3. The floated residues are then dried and hand sorted where applicable.
The flotation process allows us to separate soil particles from small objects that aren't recovered by eye during trowelling.
Seeds, carbonised grains, small finds, macrofossil flora and fauna, and metallic particles such as hammerscale can all be recovered from the floated residues. Sorted samples are added to the database and sent away for specialist analysis under the microscope.
The soils we excavate from the site are all processed through the dry sieves on site - when your bucket is full, you sieve the contents before discarding your spoil.
This gives you the chance to find some of the smaller items that might be missed as you trowel a layer or dig a feature.
By sampling deposits in 20 cm squares, we can plot the distribution of hammerscale - the metallic particles produced by hammering hot metal in a forge. This will help us determine the focus of metalworking activity, and the shape and size of the scale itself is evidence for the type of metalworking from blacksmithing to high temperature welding.