Southerham Works Pit
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Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| TQ426094 | — | Unfavourable Declining | 0.95 | 2022-03-30 |
Geology & landscape
Geological Period: Cretaceous · Rock Type: Chalk, Flint
Description
Description The Lewes area has the thickest and most complete chalk sequence in southern England. The chalk pits in the area are therefore particularly important for defining the lithostratigraphy of the chalk succession. Southerham Works Pit, which is located on the northern limb of the Kingston Beddington Anticline, exposes Middle and Upper Chalk of Turonian to Coniancian age c. 90 87 Ma. The site provides the best remaining exposures through the Ranscombe, Lewes and Seaford Members, this being the only remaining locality to expose the Lewes Member. The Ranscombe and Lewes Members are characterised by nodular chalk and hardgrounds notably Strahan's Hardground and the overlying Seaford Member is more typically a soft white chalk with numerous and laterally persistent flint horizons. The Lewes area has also long been famous for the exceptional diversity of fossil fish from its chalk pits. The fish fauna from this area was figured in detail by Woodward in his 190212 monograph which is still the standard work on the fossil fish of the English chalk. Individual species from Lewes are frequently represented by large numbers, many of which comprise complete, articulated skeletons without serious distortion. At least twenty seven type specimens have been described from the Lewes area; most commonly these include the Chondrichthyes including sharks, skates and rays and Osteoichthyes bony fish. The precise origin of much of this type material is unknown usually cited as 'Lewes area', however, the near complete sequence through Middle and Upper Chalk at Southerham Works Pit makes this an important site for the continued study of Upper Cretaceous fish. Southerham Works Pit is therefore a key locality for defining Upper Cretaceous lithostratigraphy, understanding the environments of the Upper Cretaceous chalks and understanding the community structure, evolution and taxonomy of Upper Cretaceous fish.