of Pladda Island, south-east coast of Arran, opposite Kildonan,
south-east coast of Arran, opposite Kildonan. Buteshire. A Tertiary
columnar quartz-dolerite sill is intrusive into the Triassic sandstone.
The photograph also gives a good view of the lighthouse.
The island, 800 metres long and 21 metres high is composed almost
entirely of sill. The cliff represents an old cliff line formed
by marine erosion, below which is a raised beach of the Main Postglacial
Shoreline times, a time when the sea level was higher.
ID: 000-000-146-231-C; British Geological Survey