. "Ashfell Limestone Formation"@en . "Thickness The formation is 40-50 m thick at Penrith and Brough, but thickens to 100 m in the Stainmore Trough."@en . "Hillbeck Limestone [Obsolete: use AFL]"@en . "Limestone with subsidiary mudstone, sandstone and siltstone. Stratified bedrock. Occurs onshore. Deposited during the Holkerian Substage (Carboniferous Period) (343-337 Ma BP)."@en . "AFL"@en . . . . "The distinctive Ashfell Limestone Formation is characteristically dark grey to dark blue-grey and mainly a packstone, shelly grainstone or lime mudstone. Strongly cross-bedded units, with thin interlaminae of siltstone and fine-grained sandstone occur at the base of the formation. Convolute beds and nodules of dark grey chert occur locally, and partial dolomitisation is common. The top of the formation is marked by the presence of dark grey, cross-bedded, coarse-grained crinoidal grainstone, grey mudstone with bivalves, and vuggy porcellanous limestone (the Bryozoa Band of Garwood, 1913). \r\n\r\nShallow marine, perhaps slightly restricted carbonate environment. Holkerian."@en . "The mainly packstone, shelly grainstone or lime mudstone of the Ashfell Limestone Formation conformably overlies the sandstones, mudstones and thin limestones of the Ashfell Sandstone Formation."@en . . "343.0"^^ . . "Ashfell Limestone Formation"@en . "stable"@en . . . . . "337.0"^^ . "On the northern margin of the Stainmore Trough, the Bryozoa Band (BZB) at the top of the Ashfell Limestone Formation is overlain either conformably by the mainly sparry packstone of the Potts Beck Limestone Formation, or disconformably by the rhythmically bedded limestone (mainly wackestone and packstone) of the Knipe Scar Limestone Formation."@en .