Bierton Clay Pit

Site of Special Scientific Interest · 51.8336, -0.7841

Condition (Natural England)

Unfavourable Declining (1)
UnitFeatureConditionArea (ha)Assessed
SP838156 Unfavourable Declining 0.07 2023-01-27

Geology & landscape

Geological Feature: Rock Outcrop · Geological Period: Jurassic

Description

Area, 0.07 hectares 0.2 ac Description An historic section in late Jurassic strata spanning the Kimmeridgian and Portlandian Stages. Here is exposed the only permanent section in the lower Portland Beds north of Oxford and thus at the northern extremity of the Portland outcrop. This includes the basal Upper Lydite Bed, a transgressive pebble horizon traceable across the south Midlands. This unit rests on P. pallasioides Zone Kimmeridge Clay and thus marks a major non sequence terminated by deposition of glaucolithus Zone, or possibly okusensis Zone strata above. A unique stratigraphic site showing the relationship between Portland Beds and the Hartwell Clay.