. . . . . . "School Limestone"@en . "stable"@en . "Limestone with subsidiary calcareous mudstone. Stratified bedrock. Occurs onshore. Deposited during the Brigantian Substage (Carboniferous Period) (330.9-330.3 Ma BP)."@en . "GGL"@en . "330.9"^^ . . . "Penton Limestone"@en . "Pale grey compact even-bedded limestone and subordinate shaly calcareous mudstone."@en . "Greengate Well Limestone"@en . "330.3"^^ . . . "c. 10 m maximum, thinning eastwards to about 5 m; locally split by c. 1.5 m of calcareous shaly mudstone."@en . "Greengate Well Limestone"@en .