XIV.—The Igneous and Metamorphic History of Cromar, Deeside, Aberdeenshire

Abstract

Middle and Lower Deeside lie within the belt of injection and high-temperature metamorphism made famous by the pioneer researches of Mr George Barrow. In this paper are recorded the results obtained from a study of Cromar, an area small enough to admit of detailed petrographical treatment and yet large enough to exhibit a considerable variety of igneous and metamorphic phenomena. Of the three great phases of igneous activity there displayed, one is older than the epoch of maximum crustal movements, the second is closely connected with these, and the third is later; the rocks of each period have their own quite definite chemical, petrographical, and geological characteristics. Whilst here most attention will be directed towards the second group, that associated with the movements, an account of the other two groups will be given adequate for a discussion of the full igneous history of the area.