In 2008 a small archaeological evaluation was carried out at Knockhall County Primary School in advance of the construction of temporary structures related to a children's centre. A single trial trench was excavated with two geoarchaeological test-pits, one at each end of the trench.

No archaeological features were discovered but a small assemblage of six pieces of worked flint was found as well as a single piece of unworked burnt flint. The assemblage contained a mixture of debitage and implements including flake cores, struck flakes, a blade core and scrapers . One flint dates to the mesolithic and the rest ot the neolithic and bronze age.

The geology consisted of topsoil, subsoil, a gravel deposit and natural sand and clays.

The geoarchaeological test-pits were excavated to a depth of c. 4m. They discovered no palaeolithic artefacts but did identify pleistocene deposits. From the specialist report (Dr Francis Wenban-Smith) : "The upper c. 0.7 m of deposits at the site comprised clean gravel which was interpreted as made ground on the basis of contained Late Prehistoric flint artefacts and fire-cracked flint. Beneath this, undisturbed Pleistocene deposits were present at the west end of the evaluation trench, bottomed on to Thanet Sand at a depth of 4 m below the ground surface. There were also Pleistocene deposits present at the east end of the evaluation trench, but these seemed to have been affected by some sort of geological disturbance, and did not contain a well-defined terrace sequence.

Despite sieving 640 litres of gravel from the well-defined gravel bed at the west end of the trench, no artefacts were found. The work at the site has provided a useful record of in situ terrace deposits in the key Swanscombe area. The deposits are probably attributable to the Swanscombe Boyn Hill terrace, probably mostly equivalent to the Lower Middle Gravel, despite the absence of archaeological finds.

Two gravel samples were taken for clast lithological analysis, by David Bridgland (Department of Geography, University of Durham). The results indicate a post-Anglian Thames gravel, which supports the suggested correlation above with the Swanscombe Lower Middle Gravel." (1)

<1> Archaeology South-East, 2008, An archaeological evaluation at Knockhall School, Greenhithe, Kent (Unpublished document). SKE30844.