Stratigraphy and structure of the western Moine and the problem of Moine orogenesis

Abstract

The stratigraphy and major structure of some 650 km 2 of Precambrian, Moine metasediments in western Scotland are discussed and it is shown that at least four major deformation phases involving primary isoclinal folding with fold amplitudes of at least 20 km, and two major metamorphic episodes affect both the Lewisian basement and the Moine cover. It is argued that there is sufficient evidence to regard the first two deformation phases together with the earlier metamorphism as Precambrian in age and the subsequent deformations and metamorphism as Caledonian.