Reed's Farm Pit
Also within
Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| ST212003 | — | Unfavourable No Change | 0.76 | 2010-08-11 |
Climate exposure
This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.
Coastal habitats are exposed to sea-level rise and storm erosion. Where hard sea defences sit behind them, there's nowhere landward to retreat to — a squeeze that keeps compressing the habitat no matter how well it's managed.
Geology & landscape
Mining / Industrial: Quarry · Geological Period: Cretaceous · Rock Type: Chalk, Greensand, Limestone
Landscape processes: Coastal
Description
Description This well known old locality has several alternate names Hutchins Pit, Waterworks Pit but still exhibits important exposures of Cretaceous sediments. The base of the sequence recorded is the Eggardon Grit 'Member', part of the Upper Greensand Formation, the top surface of which is a mineralised hard ground possibly equivalent to the Small Cove Hardground of the Devon coast. The overlying basement bed of the 'Wilmington Sands' is a rich shell bed with many bivalves including trigoniids and an important and unusual ammonite fauna of the couloni horizon at the top of the caritanense Subzone of the mantelli Zone Lower Cenomanian. The succeeding sands contain rare specimens of the ammonite Austiniceras, but overlying calcareous sandstones, known locally as 'Grizzle', yield a richer fauna of the dixoni Zone. Exact correlation of the 'Wilmington Stands' with coastal sequences in South East Devon remains unclear, but there is general equivalence at least in part, to the Pounds Pool Sandy Limestone and the Hooken Nodular Limestone members of the Beer Head Limestone Formation. A succeeding limestone unit capped by a mineralised hardground yields a sparse fauna of the rhotomagense Zone Middle Cenomanian correlation with the Little Beach Bioclastic Limestone Member Beer Head Limestone Formation of coastal sections is often assumed. The overlying glauconitic chalk although often correlated with the Pinnacles Glaunconitic Limestone Member of the coastal Beer Head Limestone Formation, is already lithologically' Lower Chalk'. It yields a derived phosphatised fauna with elements of the jukes brownei Zone Middle Cenomanian and the guerangeri Zone Upper Cenomanian. An indigenous fauna however, indicates the younger geslinianum Zone also Upper Cenomanian. The richness of some of the internationally important faunas, especially the correlative elements such as ammonites makes Reed's Farm Pit of national and international significance. Although the succession is broadly similar to that of the nearby Wilmington Quarry White Hart Sandpit SSSI, many significant differences are present and Reed's Farm Pit has yielded better preserved specimens of certain faunal elements. Both sites are stratigraphically complementary.