The Corallian Limestone aquifer is present at outcrop in Yorkshire and in the Cotswolds.
In Yorkshire it consists of limestones and grits up to about 110 m thick, thinning to about 20 m towards the south of the region, where the limestones are progressively replaced by clay. It is typically well jointed and gives rise to numerous springs. Here it yields up to 15 l/sec.
In the Cotswolds the aquifer is up to 40 m thick, give yields of 5 to 10 l/sec, with water quality becoming increasingly saline down dip as the aquifer becomes confined in the Wessex Basin.
See also the Corallian Limestone in the BGS lexicon of named rock units.
Yorkshire and southern England.
In Yorkshire the base of the Corallian Limestone unit dips from the west where it is at about 300 m above OD to the south east coast where it is below OD. In southern England the base of the aquifer is highest at its outcrop in the Cotswolds, at about 50 to 100 m above OD, and it dips into the centre of the Wessex Basin to a depth of about 1500 m below OD.
Please contact BGS Enquiries for more information.