Appendix A classifications vs published lacustrine OD (~15–28 m). Sheet 293 / DigMap TILMP covers head on the Hele–Bickington ridge (BH9–11 clay tops ~38–40 m OD), above the lacustrine basin.
Section A · Higher Gorse / Lake → Roundswell · holes within ~420 m of the line.Section B · N–S across Hele–Bickington ridge · holes within ~450 m of the line.