"Grit Sill"@en . . "Grit Sill"@en . . . "330.3"^^ . . . "stable"@en . "Sandstone. Igneous intrusive bedrock. Occurs onshore. Emplaced during the Pendleian Substage (Carboniferous Period) (330.3-327 Ma BP)."@en . "GRS"@en . . . "327.0"^^ . "Sandstone."@en . .