Geology for ELR BAC3 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 |
|---|---|---|---|
| 149M 0503y to 152M 0275y | Zechstein Group - Dolomitised Limestone and Dolomite | ||
| 152M 0275y to 155M 0165y | Pennine Middle Coal Measures Formation and South Wales Middle Coal Measures Formation Ⓤ | ||
| 155M 0165y to 155M 0515y | Clay, Silt and Sand | Alluvium | Pennine Middle Coal Measures Formation and South Wales Middle Coal Measures Formation Ⓤ |