Old Town Railway Cutting, Swindon

Site of Special Scientific Interest · 51.5468, -1.7820

Also within

Wiltshire County

Condition (Natural England)

Unfavourable Declining (2)
UnitFeatureConditionArea (ha)Assessed
SU152831 Unfavourable Declining 1.84 2023-01-18
SU154833 Unfavourable Declining 1.84 2023-01-18

Geology & landscape

Geological Feature: Rock Outcrop · Geological Period: Jurassic

Description

Description A key late Jurassic locality spanning the Kimmeridgian and Portland Stages from the Shotover Grit Sands pectinatus zone to the lower Swindon Sand and Stonekerberus zone. It includes two marked non sequences, marked by pebble horizons, the Lower and Upper Lydite Beds, which may be traced from Wiltshire to Buckinghamshire but are normally obscured at outcrop. One of a very few outcrops of late Jurassic age, showing the only Kimmeridgian Exogyra Bed Swindon Clay section and the most extensive lower Portland Bed succession in the famous Swindon outlier. Unique exposures showing the final episodic phase of deposition characterising the late Kimmeridgian and Portlandian and enbling correlations with the fuller, standard sections in Dorset.