Clitheroe Knoll Reefs
Also within
Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| SD769430 | — | Favourable | 16.31 | 2024-02-08 |
| SD773443 | — | Unfavourable Declining | 2.73 | 2024-02-08 |
| SD774433 | — | Favourable | 10.29 | 2024-02-08 |
| SD774443 | — | Unfavourable Declining | 2.73 | 2024-02-08 |
| SD776437 | — | Favourable | 11.39 | 2024-02-08 |
| SD777433 | — | Favourable | 24.96 | 2024-02-08 |
| SD782438 | — | Favourable | 20.02 | 2024-02-08 |
| SD788436 | — | Favourable | 31.79 | 2024-02-08 |
Geology & landscape
Geological Period: Carboniferous · Rock Type: Carboniferous Limestone, Limestone
Description
Area, 115.3 hectares 284.9 ac Description This geological site near Clitheroe is comprised of a road cutting and a series of small hills running east west between the villages of Worston and Downham. The hills are important examples of early Carboniferous knoll reefs. In conjunction with other well exposed Clitheroe sites this site shows the best examples of such reefs which developed during the Chadian Stage in the Craven Basin. The nature and origins of the reefs have always been matters of controversy. This locality provides a unique opportunity to examine such carbonate build ups, here expressed as actual knolls in the topography of the present day. To the north of the knolls a cutting on the A59 road has exposed a seventy metre thick section of the Carboniferous Limestone, represented by the Horrocksford Beds and overlying Bankfield Beds. This important section includes the proposed boundary stratotype for the Chadian Stage, which is placed on the junction of these two rock units. The site has been sampled for foraminifera, which have been used as stratigraphic indicators, including the genus Eoparastafella which makes its appearance a few metres above the boundary. This is a key locality for stratigraphic studies in the Lower Carboniferous.