Three ancient artifacts on a grid paper background, including a small rectangular fragment, a larger intact piece with carved lines, a stack of three metal containers with labels, and a small square Roman dice from Quintana Gate, Exeter.

Residue Sorting

Post processing, all residues, flots and finds are quantified and bagged separately.   If required residues can be fractionated and sorted for ecofacts, artefacts and micro-artefacts.  Endocott sieves are used to divide the residues into fractions of 0 – 2mm, 2 – 4mm and >4mm.  A course sort is carried out on the >4mm residue portion to ensure total artefact retrieval. 

Artefact retrieval

Although the primary function of flotation is the retrieval of environmental material, it can also be used very effectively for retrieving particularly delicate or fragile artefacts from bulk samples.  The photograph to the right shows fragments of Beaker pottery which were too fragile to be excavated in the conventional manner.  Bulk samples were taken to deliberately include the pottery sherds which could then be separated from the soil by gently washing in the flotation tank.   

Various small rocks, pebbles, and dirt on a mesh surface.

Bulk samples taken for the recovery of cremated human bone can also be processed by flotation to recover bone and other materials related to pyre technology and cremation burial practice.  Residues are air-dried, fractionated and sorted for cremated boned, charcoal and plant macrofossils.