. . . . "344.5"^^ . "Upper Clifton Down Limestone Formation [Obsolete: use CDL]"@en . . . "Drybrook Limestone Formation [Obsolete: use HBO]"@en . "337.0"^^ . "stable"@en . "Cheddar Limestone Formation [Obsolete: use CDL, CDRL]"@en . . . "In the Bristol area taken at the sharp contact between the interbedded dolomite and calcite mudstones of the underlying Clifton Down Mudstone Formation and the basal sandy limestone of the Clifton Down Limestone Formation. The boundary needs further investigation. In Broadfield Down and the Mendip Hills it is taken at the incoming of calcite mudstones of the Clifton Down Limestone Formation above the oolitic and oolitic/bioclastic limestones of the Goblin Combe Oolite Formation and undivided Burrington Oolite Subgroup respectively."@en . "Limestone and trace chert, dolomitic limestone and mudstone. Stratified bedrock. Occurs onshore. Deposited during the Arundian Substage - to - Holkerian Substage (Carboniferous Period) (344.5-337 Ma BP)."@en . . . "Clifton Down Limestone Formation"@en . . "Splintery dark grey calcite and dolomite mudstones, pale grey oolitic, dark grey bioclastic and oncolitic limestones and some mudstones. Scattered cherts and silicified fossils in lower half. Sandy limestone at base in Bristol area. Deposited in a barrier/back barrier/shelf lagoon setting."@en . "Lower Clifton Down Limestone Formation [Obsolete: use CDL]"@en . "Taken at the top of the last calcite mudstones of the formation, above which occur the dark grey crinoidal and bioclastic limestones and paler oolitic limestones of the Oxwich Head Limestone Formation."@en . . "CDL"@en . "266 m in the Avon Gorge at Bristol, thinning northwards to 137 m north of Bristol and thinning southwards to 150-200 m in the Mendip Hills."@en . "Clifton Down Limestone Formation"@en .