In total 200, 000 tonnes of soil material was treated on site.

BBC: Work to decontaminate Hauxton site completed

Soil is a highly attenuating material, meaning that it is difficult for sound waves to travel far in it.

ECONOMIST: Archaeology

Capable of resolutions better than 0.1mm - the diameter of a human hair - it allows archaeologists to carefully examine material while still encased in soil.

BBC: Technology

If we were doing it again now, the material would be taken out in its soil matrix, put in a plastic bag and kept cool.

BBC: NEWS | Science/Nature | Team widens search for 'Hobbits'

Soil samples from around the stone's socket will be analysed and any organic material found radio-carbon dated if possible.

BBC: Human remains found in Bronze Age pots

Filter material: layer of fine gravel used in slope stabilization structures that allows water to escape and retains soil particles.

UNESCO: L O S S A R Y