Yesnaby Sandstone Group
|Yesnaby Sandstone Group
Stratigraphic range: Givetian (Devonian)
|Unit of||Old Red Sandstone Supergroup|
|Sub-units||Qui Ayre Sandstone Formation, Harra Ebb Sandstone Formation|
|Underlies||Caithness Flagstone Group|
|Overlies||unconformable on 'basement'|
|Extent||west coast of Mainland, Orkney|
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.
These strata are only exposed on either side of the Garthna Geo Fault in the Yesnaby area of west Mainland, Orkney.
Lithology and stratigraphy
The Group comprises the Qui Ayre Sandstone Formation and the Harra Ebb Sandstone Formation. 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.
- (BGS on-line lexicon of rock units)
- British Geological Survey 1:100,000 scale geological map (Scotland) Orkney Islands (special sheet)