Near Macduff on the Banffshire coast of northeast Scotland, the Macduff group of the Dalradian shows a 15-foot zone of graywackes which contains boulders of igneous and metamorphic rocks. The available evidence indicates that the boulders fell into the bedded deposit, and the disparity of size between the boulders and the grains of the matrix points to depositional conditions other than those of the graywacke. It is suggested that the boulders were carried by floating ice. The composition of the boulders is given (including the chemical composition of a syenitic boulder), comparable occurrences are described, and the possible age (late Precambrian or Eocambrian) is discussed.

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