| The city also lies within the north western parts of the Yorkshire Coalfield which is mostly composed of carboniferous coal measures. |
| They are mostly built from the same carboniferous limestone used at the castle. |
| The carboniferous rocks of the Yorkshire coalfield further east have produced a rolling landscape with hills, escarpments and broad valleys. |
| The coal measures are carboniferous rocks laid down between 290 and 354 million years ago. |
| A significant loss occurred when rainforests collapsed in the carboniferous. |
| A limestone pavement is an area of almost bare, flat rock and is arguably the most fascinating feature of any area of carboniferous limestone. |
