Yesnaby Sandstone Group

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Yesnaby Sandstone Group
Stratigraphic range: Givetian (Devonian)
Yensaby castle 1.JPG
Dune cross-bedded aeolian Yesnaby Sandstone exposed in the cliffs at Yesnaby and on Yesnaby Castle sea stack
Unit ofOld Red Sandstone Supergroup
Sub-unitsQui Ayre Sandstone, Harra Ebb Sandstone
UnderliesCaithness Flagstone Group
Overliesunconformable on 'basement'
OtherSiltstone, conglomerate
ExtentWest coast of Mainland, Orkney
Type section
Named forYesnaby

The Yesnaby Sandstone Group is a Devonian lithostratigraphic group (a sequence of rock strata) in west Mainland Orkney, Scotland. The name is derived from the locality of Yesnaby where the strata are exposed in coastal cliffs.[1]


These strata are only exposed on either side of the Garthna Geo Fault in the Yesnaby area of west Mainland, Orkney.

Lithology and stratigraphy[edit]

The Group comprises the Qui Ayre Sandstone and the Harra Ebb Sandstone. The basal beds are talus and alluvial fan facies deposited in a fluvial or lake marginal environment probably during the Emsian Stage of the Devonian Period.[2]


  1. ^ (BGS on-line lexicon of rock units)
  2. ^ British Geological Survey 1:100,000 scale geological map (Scotland) Orkney Islands (special sheet)

External links[edit]