Cranford St John
Also within
Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| SP921765 | — | Favourable | 1.76 | 2022-02-02 |
| SP925762 | — | Favourable | 1.01 | 2022-02-02 |
Geology & landscape
Mining / Industrial: Quarry · Geological Period: Jurassic · Rock Type: Limestone
Description
Description The quarry face at Cranford St John exhibits a section through middle Jurassic strata from the lowerpart of the Rutland Formation to nearly the top of the White Limestone Formation. It is a key site for studying middle Jurassic strata and their environments of deposition and illustrates their transitional nature between those seen to the north at Ketton and Spireswood and those seen to the south at Irchester and Wellingborough. This locality is the type section for a freshwater clay bed believed to have represented an extensive storm deposit. It is also the only exposure at this stratigraphical level, in eastern England showing the lateral passage of the Finedon beds, seen at the tops of the Rutland Formation, into the base of the White Limestone Formation. The White Limestone Formation is in part very fossiliferous and also contains a regionally developed ancient erosion surface.