Geology for ELR HDS1 is based on British Geological Survey (BGS) low-resolution data sampled at 100 metre intervals along the ELR. The geology presented should not be treated as accurate or complete. Data marked with Ⓤ is classed as undifferentiated by the BGS.
| Mileage | Material | Deposit | Bedrock |
|---|---|---|---|
| 3M 1252y to 4M 0141y | Thames Group - Clay, Silt, Sand and Gravel |