. "Gneissose pelite, gneissose psammite and migmatitic psammite with subsidiary migmatitic semipelite. Stratified bedrock. Occurs onshore. Deposited during the Tonian Period (Precambrian) (1000-720 Ma BP)."@en . "Unknown: cut by Swordly thrust."@en . "stable"@en . "Bettyhill Formation"@en . "Pink-grey psammite, gneissose, locally migmatitic, interlayered on cm-m scale with gneissose semipelite and pelite. Abundant quartzo-feldspathic segregations. At the structural base locally a c. 300 m thick sillimanite-bearing gneissose pelite unit. No sedimentary structures preserved. Abundant thin amphibolite lenses."@en . . . "BTYH"@en . "720.0"^^ . . "Bettyhill Formation"@en . " c. 1000-2000 m (post-deformational thickness)."@en . . . . "1000.0"^^ . . . "Unconformable upon Lewisian Gneiss inlier (L); unconformity highly sheared. In many places, base is cut and deformed by the Torrisdale thrust."@en .