Geology for ELR SDI1 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 |
|---|---|---|---|
| 206M 0228y to 206M 0279y | Clay, Silt and Sand | Alluvium | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 206M 0279y to 206M 0935y | Diamicton | Till | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 206M 0935y to 206M 1375y | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete | ||
| 206M 1375y to 207M 1265y | Clay, Silt and Sand | Alluvium | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 207M 1265y to 207M 1375y | Diamicton | Till | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 207M 1375y to 207M 1705y | Diamicton | Till | |
| 207M 1705y to 209M 0055y | Diamicton | Till | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 209M 0055y to 209M 1290y | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |