Abstract

On the north coast of the Inishowen peninsula, Ireland, the Fahan slates and grits (upper Dalradian), which are not inverted, show a sequence of inverted graded beds. The beds range from less than an inch to five inches in thickness and are interspersed among siltstones, quartzites, and cherty limestones. They have a laminated dark gray argillaceous basal portion overlain by a lighter colored, fine-grained, sandy portion, the two usually separated by a sharp junction. It is suggested that either two main periods of river flow during an annual cycle could account for these reversed beds, or that the climatic, geographic, and geologic environment might have made clay sediments available at an early stage in the main period of an annual cycle. As these reversed beds are much more noticeable because they are wave-washed, it is suggested that the phenomenon may be more common in inland exposures than has been recognized and caution should be used in ascribing reversed graded bedding to

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