Table 1.

Units encountered in the boreholes and the range of elevations of the top and base

StratumTop (m ATD)Base (m ATD)
Alluvium/Kempton Park Gravel100.0 – 96.085.5 – 95.5
London Clay Formation95.5 – 85.575.2 – 56.6
Harwich Formation75.2 – 56.674.2 – 61.6
Lambeth GroupSand Unit74.2 – 60.456.9 – 56.6
Sand Channels56.9 – 56.661.8 – 55.6
Laminated Beds74.2 – 59.868.8 – 55.1
Lower Shelly Beds68.8 – 55.166.6 – 53.2
Lower Mottled Beds66.6 – 53.159.9 – 48.1
Upnor Formation59.9 – 48.157.1 – 44.6
Thanet Sand Formation57.1 – 44.630.2 – 27.7
Chalk30.2 – 27.8n.a.

n.a., not analysed.