Geology for ELR BJR 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 |
|---|---|---|---|
| 0M -181y to 0M -146y | Clay, Silt and Sand | Alluvium | Pridoli Rocks Ⓤ - Mudstone, Siltstone and Sandstone |
| 0M -146y to 0M 0275y | Diamicton | Till | Pridoli Rocks Ⓤ - Mudstone, Siltstone and Sandstone |
| 0M 0275y to 0M 1595y | Clay, Silt and Sand | Alluvium | Pridoli Rocks Ⓤ - Mudstone, Siltstone and Sandstone |
| 0M 1595y to 1M 1265y | Diamicton | Till | Pridoli Rocks Ⓤ - Mudstone, Siltstone and Sandstone |
| 1M 1265y to 2M 0605y | Diamicton | Till | Lower Devonian Rocks Ⓤ - Mudstone, Siltstone and Sandstone |
| 2M 0605y to 2M 1705y | Lower Devonian Rocks Ⓤ - Mudstone, Siltstone and Sandstone | ||
| 2M 1705y to 3M 0275y | Lower Devonian Rocks Ⓤ - Sandstone and Conglomerate, Interbedded | ||
| 3M 0275y to 3M 0605y | Upper Devonian Rocks Ⓤ - Sandstone and Conglomerate, Interbedded | ||
| 3M 0605y to 3M 0935y | Dinantian Rocks Ⓤ - Limestone with Subordinate Sandstone and Argillaceous Rocks | ||
| 3M 0935y to 3M 1705y | Upper Devonian Rocks Ⓤ - Sandstone and Conglomerate, Interbedded | ||
| 3M 1705y to 4M 0275y | Dinantian Rocks Ⓤ - Limestone with Subordinate Sandstone and Argillaceous Rocks | ||
| 4M 0275y to 4M 0495y | Millstone Grit Group - Mudstone, Siltstone and Sandstone | ||
| 4M 0495y to 4M 0825y | Pennine Lower Coal Measures Formation and South Wales Lower Coal Measures Formation Ⓤ | ||
| 4M 0825y to 4M 1265y | Pennine Middle Coal Measures Formation and South Wales Middle Coal Measures Formation Ⓤ | ||
| 4M 1265y to 4M 1620y | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |