Home

Metamorphic Terranes in NW Scotland

The west coast of Scotland and Outer Hebrides have well-exposed Lewisian basement of the North Atlantic Craton. The Scourian Complex is a nucleus of high-grade Archaean gneiss terrane. The remainder of the Lewisian basement is of Proterozoic age and strongly metamorphosed and reworked in the Palaeoproterozoic Laxfordian Orogeny. The remainder of the Scottish Highlands to the east is Neoproterozoic Moine Supergroup that was metamorphosed in the Cambrian Caledonian Orogeny. The Caledonian Orogen is thrust over basement rocks of the west coast at the Moine Thust.
 

 

 

 

 

 

 

 

 

 

 

 

[Map from Baba et al., 1998]                                   [Map from Spear, 1993]

ITAR is undertaking a field program in western Scotland in 2012 as part of an ongoing research strategy to investigate a broad range of ancient and modern terranes (i.e. Galapagos and Andes) from a variety of tectonic settings for comparison with the orogenic systems being investigated in the Yilgarn Craton, Himalayas and Pan-African Orogenic System. Archaean gneisses of the Scourian Complex will be compared with the high-grade gneissic and granulite terranes in the Southwest Terrane of the Yilgarn Craton. Thermobarometric and deformation effects on Lewisian basement due to the Caledonian Orogeny, will be compared with reworking of the Yilgarn Craton margins by the Gascoyne, Pinjarra and Albany Fraser Orogens. Metamorphic field gradients across the Caledonian Orogen will be compared with those in the Damara Orogen, for which the two orogenic systems superficially share many features in common.