Geology for ELR WEL1 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 |
|---|---|---|---|
| 6M 1026y to 7M 0385y | Thames Group - Clay, Silt, Sand and Gravel | ||
| 7M 0385y to 7M 1595y | Sand and Gravel | River Terrace Deposits Ⓤ | Thames Group - Clay, Silt, Sand and Gravel |
| 7M 1595y to 9M 0352y | Thames Group - Clay, Silt, Sand and Gravel |