. . . . "Apparently 1500m thick in Glen Turret and vicinity, but this is probably inflated by tectonic thickening. Thins rapidly south-westwards and is absent on Auld Craig (NO 455 782)."@en . . "1000.0"^^ . . . "stable"@en . "Psammite, mostly feldspathic and slightly micaceous, interbedded with and transitional to muscovite-biotite-semipelite with low magnetic susceptibility: contains beds of calc-silicate rock and rare limestone."@en . "Glen Turret Psammite And Semipelite Member"@en . "GTP"@en . . "Incoming of beds of dark biotitic semipelite with high magnetic susceptibility at base of Glen Effock Schist Formation."@en . "Psammite and semipelite with subsidiary calcsilicate-rock and trace limestone and metalimestone. Stratified bedrock. Occurs onshore. Deposited during the Neoproterozoic Era (Precambrian) (1000-541 Ma BP)."@en . "Glen Turret Psammite And Semipelite Member"@en . "541.0"^^ . "Change from more massive and quartzose psammite at top of Glen Tanar Quartzite Member; this change is typically gradational."@en .