What is the Hebridean Terrane?
Q: What is the Hebridean Terrane?
A: The Hebridean Terrane is one of the terranes that form part of the Caledonian orogenic belt in northwest Scotland. Its boundary with the neighbouring Northern Highland Terrane is formed by the Moine Thrust Belt.
Q: What type of rocks make up its basement?
A: The basement rock is formed by Archaean and Paleoproterozoic gneisses of the Lewisian complex.
Q: What sedimentary layers are present on top of this basement?
A: They are overlaid unconformably by Neoproterozoic Torridonian sediments, which in turn are unconformably overlain by a sequence of Cambro-Ordovician sediments.
Q: How did it form during continental collision?
A: It formed part of the Laurentian foreland during the Caledonian continental collision.
Q: Where can similar rocks be found outside Scotland?
A: Similar rocks are also thought to be present on Shetland. They have been proved west and north of the Outer Hebrides by BGS shallow boreholes and hydrocarbon exploration wells.
Q: How far does this terrane extend to the west?
A: The full extent of this terrane to the west is obscured by the effects of Mesozoic rifting.
Q: Are there any other areas where similar rocks occur outside Scotland? A: Some similar rocks occur in Shetland, which are the northern outpost of the Caledonian orogeny.
