A very large quantity of Iron Age pits were discovered during excavations on Plateau 8 of the Thanet Earth site. Sherds from several prehistoric pots were uncovered within these, some may have contained cremation burials and others possibly votive offerings. 176 (of 384) were classified as storage pits, many of the others may have also been cut for storage but were smaller in size, and it is likely that several of those defined as rubbish pits may have started life as storage pits. Alongside the sherds of pottery, finds including loom weights and quern stones were also uncovered in some of the pits, possibly suggesting site specialisms.

The definition here of a storage pit was defined as having a distinct flat base which meets the sides at 60–100 degrees. In general, the Iron Age pits on Plateau 8 were circular, though most featured slight irregularities. There were also differences in the way they were cut. open shaped pits were defined as those where the lower breaks of slope formed obtuse angles. On Plateau 8 this form predominated, accounting for 46 per cent of pits. Cylindrical pits were formed by those features where the sides were generally vertical and bases were flat. Approximately 23 per cent of pits were of this category. Undercut pits were classified as those where the upper break sloped away from the pit interior, forming a reflex angle from the horizontal. In all, this category contained approximately 14 per cent of the total number of pits.

It seems certain then that a large proportion of Iron Age pits at Thanet Earth and elsewhere relate to the storage of seed grain and other goods. What is less clear is why such features appear in far greater numbers at the beginning of the Iron Age. A new set of cultural traditions focussed on the protection offered it by deities of the underworld has been suggested as a reason for the increased number of storage pits. It has also been argued that the increasingly insular power structure, less focused on control of precious metals and more on control of grain surpluses, can explain the preponderance of storage pits in the middle Iron Age. Perhaps more relevant, are the issues of raiding and diversification of storage, such considerations do not seem implausible in the Iron Age, characterised as it was by increased territorial and climatic uncertainty. In France, pits are common across a wide range of sites, but the emergence of ‘pit cluster’ sites apparently isolated from nearby settlement activity has led to speculation such areas were used specifically for the storage of surplus grain. the Plateau 8 site was clearly not of this type, due to the huge quantities of domestic finds recovered from the area, nevertheless, the themes of centralisation and specialisation that have characterised the interpretations of these sites remain consistent with those used to explain similar sites in the United Kingdom.

In sum, it would seem that a large proportion of the pits served as storage silos, with the shallower scoop like features having some other largely unidentifiable purpose. It is likely that the spoil produced during their excavation would have provided a useful raw material, perhaps used during the construction of buildings as daub, or for the manufacture of pottery. Latterly, as they fell out of use they gained a secondary function, being used as refuse pits. Due the nature of their backfills, it is not easy to estimate how long they served in either capacity particularly as both pottery seriation and absolute dating, both rather limited at Thanet Earth, correlates more strongly to their secondary use.

<1> Canterbury Archaeological Trust, 2023, Beneath the Seamark: 6000 Years of an Islands History (Monograph). SKE55405.