Geology for ELR SDI2 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 -022y to 0M 0825y | Diamicton | Till | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 0M 0825y to 1M 0385y | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete | ||
| 1M 0385y to 2M 0275y | Diamicton | Till | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 2M 0275y to 2M 0825y | Peat | Peat | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 2M 0825y to 3M 0275y | Clay, Silt and Sand | Alluvium | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 3M 0275y to 4M 0715y | Diamicton | Till | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 4M 0715y to 4M 1155y | Sand and Gravel | Glacial Sand and Gravel | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 4M 1155y to 5M 1595y | Diamicton | Till | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 5M 1595y to 6M 0385y | Sand and Gravel | Glacial Sand and Gravel | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 6M 0385y to 8M 0825y | Diamicton | Till | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 8M 0825y to 9M 0715y | Sand and Gravel | Glacial Sand and Gravel | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 9M 0715y to 9M 1265y | Clay, Silt and Sand | Alluvium | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 9M 1265y to 9M 1595y | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete | ||
| 9M 1595y to 10M 0385y | Clay, Silt and Sand | Alluvium | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 10M 0385y to 10M 1155y | Sand and Gravel | Glacial Sand and Gravel | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |
| 10M 1155y to 10M 1434y | Clay, Silt and Sand | Alluvium | South Wales Upper Coal Measures Formation - Mudstone, Siltstone, Sandstone, Coal, Ironstone and Ferricrete |