Sandstones of the Dunvegan Formation from the type area are described with respect to texture, composition, and K-Ar dates from K-feldspars. Investigations on grain size distribution indicate that the sandstones are submature and medium-grained. On the basis of size parameters it is inferred that the provenance was not restricted to one type of rock and that the sorting effect of the environment was poor. The composition of the sandstones suggests that sedimentary rocks were probably major contributors to the sediment, and igneous and metamorphic rocks supplied a lesser proportion of the detritus.

K-Ar dates from the K-feldspars of two samples agree with the Late Jurassic age assigned to early orogenies in the Cordillera to the west. Differences in the two dates support the hypothesis that the Dunvegan sediments were derived by unroofing of rising Cordilleran batholiths to the west.

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