"Beinn Mheadhoin Pebbly Psammite Formation"@en . . "541.0"^^ . . "Gairbeinn Psammite Formation [Obsolete: use BMPP, GABR]"@en . . "Feldspathic psammite (arkosic) with thin semipelite beds and gritty beds with abundant quartz and feldspar clasts."@en . "BMPP"@en . . . . . "1000.0"^^ . "stable"@en . "Conformably overlain by Ruthven Semipelite Formation, sharp disconformity and marked lithological change from psammitic sequence to gneissose semipelite."@en . "Psammite with subsidiary quartzite and semipelite. Stratified bedrock. Occurs onshore. Deposited during the Neoproterozoic Era (Precambrian) (1000-541 Ma BP)."@en . . "Beinn Mheadhoin Pebbly Psammite Formation"@en . "Not exposed; unknown."@en . .