Sea, old sculptor, carves from the western ramparts
George Mackay Brown
Image of Duncansby Stacks courtesy of Alan Moar
The coast of Caithness is an outstanding location to study the erosion of hard rock coasts. Together with Orkney, it forms the finest coastline developed on Devonian rocks in Europe, if not the world. Evidence of continuing erosion is not hard to find. Cliffs show scars from rock falls and blocks have been torn from shore platforms. The destruction of the Wick breakwater in the 19th century was a world-renowned example of the power of the sea This dynamism reflects the ferocity of North Atlantic and North Sea storms and major changes at the coast can often be linked to the greatest storms. Rates and styles of marine erosion and cliff retreat can be assessed in Caithness, unlike on many other coasts where change is very slow.
The effects of rock type and structure are also simplified. The Devonian flagstones and sandstones are often flat-lying and divided into cuboidal blocks of various sizes by bedding planes and joints. The flagstone beds have markedly different resistances to weathering and erosion, giving fretted outlines to cliffs and complex geometries to shore platforms. Marine erosion attacks this ancient but simple masonry, allowing classic models of cliff evolution to be tested.
As elsewhere in Scotland, elements of the more sheltered part of the Orkney coastline are inherited from the period before the last ice sheet. Shore platforms often pass below till left by the last ice sheet.