CTSDs

Kilns of Brin Novan

 

 

 

Quoy Geo

Significance: Quoy Geo (HY 382348) shows fine examples of cliff-top storm deposits. These features show that wave action during intense storms can reach heights of 10 or even 20 m OD. Comparable features occur on Orkney at Sacquoy Head and Scabra Head, Rousay (Wilson et al. 1935) and The Nev, Westray.

The cliff top at Quoy Geo is approximately 18 m above sea level and its face is vertical above a stepped base. The cliff-top shows a 40 m wide wave-washed platform which slopes seaward at 3. The platform lacks debris but show scars of recent block removal. To the rear of the platform is the eroded edge of a 4 m-high storm ridge resting on till. The front edge of the ridge is formed of large imbricate sandstone blocks, with slabs of 1 m diameter resting in a breccia matrix. This material shows little sign of weathering or lichen-growth but rests on more weathered breccia. The gentle, landward-facing slope of the ridge shows lichen-covered blocks up to 2 m across which are clearly relatively old, overlain by younger, smaller fresh debris and turned-over blocks. The turf to the rear of the ridge has embedded blocks up to 1.5 m across with clusters of imbricate blocks and also a scatter of air-thrown pebbles.

The cliff-top at Quoy Geo is beyond the range of normal wave attack and the features are a product of winter storms. Waves reached the cliff top platforms during the storm of 24/02/2004 (Woodman-Smith, 2004). Cliff retreat tends to destroy cliff-top storm deposits and waves in recent storms have clearly attacked the storm ridge and moved debris landward, leaving a range of man-made debris. The presence of weathered storm debris and of large lichen-covered blocks is highly suggestive of earlier storm events of very high magnitude, Suitable material for dating these events seems to be lacking at Quoy Geo but the degree of weathering indicates that these storms must surely predate the last few centuries. Sites such as Quoy Geo therefore have the potential to provide a chronology of major storms on the Northern Isles.