Once human remains have been carefully excavated on site, the skeletons are brought to the office. At the time of excavation, each skeleton is divided into several bags to keep the different elements separate.
Here, they are washed within our processing facilities with soft bristled toothbrushes and sponges. This is done delicately to make sure that any bone abnormalities, stains and/or lumps aren’t scrubbed away by accident, as a specialist will need to see these to identify if there are any indications of disease or injury present on the remains.
Occasionally, neonate (infant) skeletons are lifted in a block of soil, known as a ‘block lift’. This is where the soil surrounding the bones is scooped up with the bones themselves. This is often done when the remains are too fragile and/or too tiny to be picked up by hand due to the young age at which the individual died. Neonate bones are not fused, as our skeletons fuse as we grow, a process which finishes in early adulthood. This means that block lifting can help recover all the tiny bones, such as the unfused vertebrae and finger bones.
Some adult bones are also occasionally block lifted. This may include the hands and feet in order to have a higher chance of recovering all the small bones contained within them. Skulls might be block lifted as well to retain teeth and to have a higher chance of the recovery of tiny ear bones that can be lost during excavation.
Once all the bones have been washed, the remaining soil in the bag is gently rinsed over a 500-micron sieve to wash away all the sediment and see if any small bones or bone fragments remain. If there are, they are picked out and put with the rest of the skeleton to dry.
With block lifted neonate remains, our Siraf tank can be used to wet sieve for bone retrieval. This is where the soil is put into a 500-micron mesh within the Siraf tank, and any obvious bits of bone are picked out before the water is turned on. Once the water is flowing, the soil is then gently aggregated and some bone may float to the surface and be caught in the sieve at the end of the tank or, once all the clay/silt is flushed away, the remaining clean residue is then examined and any fragments of bone are picked out. This can also be done by bucket floatation, which is often a good option if processing needs to be done onsite. The stony residue is then discarded.
Once the skeletons are dry, they are bagged up into fresh clean bags, again ensuring that individual elements are separated ready to be assessed by a specialist.